Full text data of XG
XG
(PBDX)
[Confidence: high (a blood group or CD marker)]
Glycoprotein Xg (Protein PBDX; Flags: Precursor)
Glycoprotein Xg (Protein PBDX; Flags: Precursor)
BGMUT
xg
787 xg XG XG Reference Reference 8054981 AF380356 Ellis et al. Nat Genet. 1994 6(4) 394-400 Santosh Patnaik, Albert Einstein College of Medicine 2005-10-26 NA
787 xg XG XG Reference Reference 8054981 AF380356 Ellis et al. Nat Genet. 1994 6(4) 394-400 Santosh Patnaik, Albert Einstein College of Medicine 2005-10-26 NA
UniProt
P55808
ID XG_HUMAN Reviewed; 180 AA.
AC P55808; E9PCH1; Q496N8; Q496N9; Q496P0; Q71BZ5;
DT 01-NOV-1997, integrated into UniProtKB/Swiss-Prot.
read moreDT 01-NOV-1997, sequence version 1.
DT 22-JAN-2014, entry version 104.
DE RecName: Full=Glycoprotein Xg;
DE AltName: Full=Protein PBDX;
DE Flags: Precursor;
GN Name=XG; Synonyms=PBDX;
OS Homo sapiens (Human).
OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC Mammalia; Eutheria; Euarchontoglires; Primates; Haplorrhini;
OC Catarrhini; Hominidae; Homo.
OX NCBI_TaxID=9606;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC TISSUE=Bone marrow;
RX PubMed=8054981; DOI=10.1038/ng0494-394;
RA Ellis N.A., Ye T.Z., Patton S., German J., Goodfellow P.N., Weller P.;
RT "Cloning of PBDX, an MIC2-related gene that spans the pseudoautosomal
RT boundary on chromosome Xp.";
RL Nat. Genet. 6:394-400(1994).
RN [2]
RP NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 1).
RA Naoko S., Fujiki K., Kanai A., Tanaka Y., Iwata T.;
RT "Identification of PBDX gene highly expressed in human cornea.";
RL Submitted (MAY-2001) to the EMBL/GenBank/DDBJ databases.
RN [3]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RX PubMed=15772651; DOI=10.1038/nature03440;
RA Ross M.T., Grafham D.V., Coffey A.J., Scherer S., McLay K., Muzny D.,
RA Platzer M., Howell G.R., Burrows C., Bird C.P., Frankish A.,
RA Lovell F.L., Howe K.L., Ashurst J.L., Fulton R.S., Sudbrak R., Wen G.,
RA Jones M.C., Hurles M.E., Andrews T.D., Scott C.E., Searle S.,
RA Ramser J., Whittaker A., Deadman R., Carter N.P., Hunt S.E., Chen R.,
RA Cree A., Gunaratne P., Havlak P., Hodgson A., Metzker M.L.,
RA Richards S., Scott G., Steffen D., Sodergren E., Wheeler D.A.,
RA Worley K.C., Ainscough R., Ambrose K.D., Ansari-Lari M.A., Aradhya S.,
RA Ashwell R.I., Babbage A.K., Bagguley C.L., Ballabio A., Banerjee R.,
RA Barker G.E., Barlow K.F., Barrett I.P., Bates K.N., Beare D.M.,
RA Beasley H., Beasley O., Beck A., Bethel G., Blechschmidt K., Brady N.,
RA Bray-Allen S., Bridgeman A.M., Brown A.J., Brown M.J., Bonnin D.,
RA Bruford E.A., Buhay C., Burch P., Burford D., Burgess J., Burrill W.,
RA Burton J., Bye J.M., Carder C., Carrel L., Chako J., Chapman J.C.,
RA Chavez D., Chen E., Chen G., Chen Y., Chen Z., Chinault C.,
RA Ciccodicola A., Clark S.Y., Clarke G., Clee C.M., Clegg S.,
RA Clerc-Blankenburg K., Clifford K., Cobley V., Cole C.G., Conquer J.S.,
RA Corby N., Connor R.E., David R., Davies J., Davis C., Davis J.,
RA Delgado O., Deshazo D., Dhami P., Ding Y., Dinh H., Dodsworth S.,
RA Draper H., Dugan-Rocha S., Dunham A., Dunn M., Durbin K.J., Dutta I.,
RA Eades T., Ellwood M., Emery-Cohen A., Errington H., Evans K.L.,
RA Faulkner L., Francis F., Frankland J., Fraser A.E., Galgoczy P.,
RA Gilbert J., Gill R., Gloeckner G., Gregory S.G., Gribble S.,
RA Griffiths C., Grocock R., Gu Y., Gwilliam R., Hamilton C., Hart E.A.,
RA Hawes A., Heath P.D., Heitmann K., Hennig S., Hernandez J.,
RA Hinzmann B., Ho S., Hoffs M., Howden P.J., Huckle E.J., Hume J.,
RA Hunt P.J., Hunt A.R., Isherwood J., Jacob L., Johnson D., Jones S.,
RA de Jong P.J., Joseph S.S., Keenan S., Kelly S., Kershaw J.K., Khan Z.,
RA Kioschis P., Klages S., Knights A.J., Kosiura A., Kovar-Smith C.,
RA Laird G.K., Langford C., Lawlor S., Leversha M., Lewis L., Liu W.,
RA Lloyd C., Lloyd D.M., Loulseged H., Loveland J.E., Lovell J.D.,
RA Lozado R., Lu J., Lyne R., Ma J., Maheshwari M., Matthews L.H.,
RA McDowall J., McLaren S., McMurray A., Meidl P., Meitinger T.,
RA Milne S., Miner G., Mistry S.L., Morgan M., Morris S., Mueller I.,
RA Mullikin J.C., Nguyen N., Nordsiek G., Nyakatura G., O'dell C.N.,
RA Okwuonu G., Palmer S., Pandian R., Parker D., Parrish J.,
RA Pasternak S., Patel D., Pearce A.V., Pearson D.M., Pelan S.E.,
RA Perez L., Porter K.M., Ramsey Y., Reichwald K., Rhodes S.,
RA Ridler K.A., Schlessinger D., Schueler M.G., Sehra H.K.,
RA Shaw-Smith C., Shen H., Sheridan E.M., Shownkeen R., Skuce C.D.,
RA Smith M.L., Sotheran E.C., Steingruber H.E., Steward C.A., Storey R.,
RA Swann R.M., Swarbreck D., Tabor P.E., Taudien S., Taylor T.,
RA Teague B., Thomas K., Thorpe A., Timms K., Tracey A., Trevanion S.,
RA Tromans A.C., d'Urso M., Verduzco D., Villasana D., Waldron L.,
RA Wall M., Wang Q., Warren J., Warry G.L., Wei X., West A.,
RA Whitehead S.L., Whiteley M.N., Wilkinson J.E., Willey D.L.,
RA Williams G., Williams L., Williamson A., Williamson H., Wilming L.,
RA Woodmansey R.L., Wray P.W., Yen J., Zhang J., Zhou J., Zoghbi H.,
RA Zorilla S., Buck D., Reinhardt R., Poustka A., Rosenthal A.,
RA Lehrach H., Meindl A., Minx P.J., Hillier L.W., Willard H.F.,
RA Wilson R.K., Waterston R.H., Rice C.M., Vaudin M., Coulson A.,
RA Nelson D.L., Weinstock G., Sulston J.E., Durbin R.M., Hubbard T.,
RA Gibbs R.A., Beck S., Rogers J., Bentley D.R.;
RT "The DNA sequence of the human X chromosome.";
RL Nature 434:325-337(2005).
RN [4]
RP NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 1).
RA Naoko S., Tanaka Y., Iwata T.;
RL Submitted (AUG-2002) to the EMBL/GenBank/DDBJ databases.
RN [5]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] (ISOFORMS 1; 2 AND 3), AND
RP VARIANT ASN-60.
RX PubMed=15489334; DOI=10.1101/gr.2596504;
RG The MGC Project Team;
RT "The status, quality, and expansion of the NIH full-length cDNA
RT project: the Mammalian Gene Collection (MGC).";
RL Genome Res. 14:2121-2127(2004).
RN [6]
RP SUBCELLULAR LOCATION.
RX PubMed=7533029; DOI=10.1038/ng1194-285;
RA Ellis N.A., Tippett P., Petty A., Reid M., Weller P.A., Ye T.Z.,
RA German J., Goodfellow P.N., Thomas S., Banting G.;
RT "PBDX is the XG blood group gene.";
RL Nat. Genet. 8:285-290(1994).
RN [7]
RP TISSUE SPECIFICITY.
RX PubMed=10688843;
RA Fouchet C., Gane P., Huet M., Fellous M., Rouger P., Banting G.,
RA Cartron J.P., Lopez C.;
RT "A study of the coregulation and tissue specificity of XG and MIC2
RT gene expression in eukaryotic cells.";
RL Blood 95:1819-1826(2000).
CC -!- SUBCELLULAR LOCATION: Cell membrane; Single-pass type I membrane
CC protein.
CC -!- ALTERNATIVE PRODUCTS:
CC Event=Alternative splicing; Named isoforms=3;
CC Name=1;
CC IsoId=P55808-1; Sequence=Displayed;
CC Name=2;
CC IsoId=P55808-2; Sequence=VSP_037319;
CC Note=No experimental confirmation available;
CC Name=3;
CC IsoId=P55808-3; Sequence=VSP_037320;
CC Note=No experimental confirmation available. Ref.5 (AAI00766)
CC sequence is in conflict in position: 131:L->P;
CC -!- TISSUE SPECIFICITY: Expressed in erythroid tissues, including
CC thymus, bone marrow and fetal liver, and in several nonerythroid
CC tissues, such as heart, placenta, skeletal muscle, thyroid and
CC trachea, as well as in skin fibroblasts. Expression is low or
CC undetectable in other tissues.
CC -!- PTM: O-glycosylated (Probable).
CC -!- POLYMORPHISM: XG is responsible for the Xg blood group system.
CC -!- MISCELLANEOUS: The gene coding for this protein is located in the
CC pseudoautosomal region 1 (PAR1) of X and Y chromosomes.
CC -!- SIMILARITY: Belongs to the CD99 family.
CC -!- WEB RESOURCE: Name=dbRBC/BGMUT; Note=Blood group antigen gene
CC mutation database;
CC URL="http://www.ncbi.nlm.nih.gov/gv/mhc/xslcgi.cgi?cmd=bgmut/systems_info&system;=xg";
CC -----------------------------------------------------------------------
CC Copyrighted by the UniProt Consortium, see http://www.uniprot.org/terms
CC Distributed under the Creative Commons Attribution-NoDerivs License
CC -----------------------------------------------------------------------
DR EMBL; X96421; -; NOT_ANNOTATED_CDS; Genomic_DNA.
DR EMBL; AF380356; AAL04055.1; -; mRNA.
DR EMBL; AF534880; AAN03481.1; -; mRNA.
DR EMBL; AC006209; -; NOT_ANNOTATED_CDS; Genomic_DNA.
DR EMBL; AC138085; -; NOT_ANNOTATED_CDS; Genomic_DNA.
DR EMBL; BC100765; AAI00766.1; -; mRNA.
DR EMBL; BC100766; AAI00767.1; -; mRNA.
DR EMBL; BC100767; AAI00768.1; -; mRNA.
DR PIR; S43791; S43791.
DR RefSeq; NP_001135391.1; NM_001141919.1.
DR RefSeq; NP_001135392.1; NM_001141920.1.
DR RefSeq; NP_780778.1; NM_175569.2.
DR UniGene; Hs.179675; -.
DR ProteinModelPortal; P55808; -.
DR STRING; 9606.ENSP00000411004; -.
DR PhosphoSite; P55808; -.
DR DMDM; 2499136; -.
DR PaxDb; P55808; -.
DR PRIDE; P55808; -.
DR Ensembl; ENST00000381174; ENSP00000370566; ENSG00000124343.
DR Ensembl; ENST00000419513; ENSP00000411004; ENSG00000124343.
DR Ensembl; ENST00000426774; ENSP00000398503; ENSG00000124343.
DR GeneID; 7499; -.
DR KEGG; hsa:7499; -.
DR UCSC; uc011mhg.2; human.
DR CTD; 7499; -.
DR GeneCards; GC0XP002663; -.
DR H-InvDB; HIX0213635; -.
DR HGNC; HGNC:12806; XG.
DR HPA; HPA021539; -.
DR MIM; 300879; gene.
DR MIM; 314700; phenotype.
DR neXtProt; NX_P55808; -.
DR PharmGKB; PA37405; -.
DR eggNOG; NOG124417; -.
DR HOGENOM; HOG000233665; -.
DR HOVERGEN; HBG086239; -.
DR OMA; GGNIYPR; -.
DR OrthoDB; EOG780RPH; -.
DR ChiTaRS; XG; human.
DR GenomeRNAi; 7499; -.
DR NextBio; 29368; -.
DR PRO; PR:P55808; -.
DR ArrayExpress; P55808; -.
DR Bgee; P55808; -.
DR CleanEx; HS_XG; -.
DR Genevestigator; P55808; -.
DR GO; GO:0005887; C:integral to plasma membrane; IDA:UniProtKB.
DR InterPro; IPR022078; CD99L2.
DR Pfam; PF12301; CD99L2; 1.
PE 2: Evidence at transcript level;
KW Alternative splicing; Blood group antigen; Cell membrane;
KW Complete proteome; Glycoprotein; Membrane; Polymorphism;
KW Reference proteome; Signal; Transmembrane; Transmembrane helix.
FT SIGNAL 1 21 Potential.
FT CHAIN 22 180 Glycoprotein Xg.
FT /FTId=PRO_0000022693.
FT TOPO_DOM 22 142 Extracellular (Potential).
FT TRANSMEM 143 163 Helical; (Potential).
FT TOPO_DOM 164 180 Cytoplasmic (Potential).
FT VAR_SEQ 85 85 G -> GS (in isoform 2).
FT /FTId=VSP_037319.
FT VAR_SEQ 125 125 G -> GRGGYRLNSRYGNTYG (in isoform 3).
FT /FTId=VSP_037320.
FT VARIANT 60 60 D -> N (in dbSNP:rs5939319).
FT /FTId=VAR_054063.
SQ SEQUENCE 180 AA; 19723 MW; DADAA9E6859C4530 CRC64;
MESWWGLPCL AFLCFLMHAR GQRDFDLADA LDDPEPTKKP NSDIYPKPKP PYYPQPENPD
SGGNIYPRPK PRPQPQPGNS GNSGGYFNDV DRDDGRYPPR PRPRPPAGGG GGGYSSYGNS
DNTHGGDHHS TYGNPEGNMV AKIVSPIVSV VVVTLLGAAA SYFKLNNRRN CFRTHEPENV
//
ID XG_HUMAN Reviewed; 180 AA.
AC P55808; E9PCH1; Q496N8; Q496N9; Q496P0; Q71BZ5;
DT 01-NOV-1997, integrated into UniProtKB/Swiss-Prot.
read moreDT 01-NOV-1997, sequence version 1.
DT 22-JAN-2014, entry version 104.
DE RecName: Full=Glycoprotein Xg;
DE AltName: Full=Protein PBDX;
DE Flags: Precursor;
GN Name=XG; Synonyms=PBDX;
OS Homo sapiens (Human).
OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC Mammalia; Eutheria; Euarchontoglires; Primates; Haplorrhini;
OC Catarrhini; Hominidae; Homo.
OX NCBI_TaxID=9606;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC TISSUE=Bone marrow;
RX PubMed=8054981; DOI=10.1038/ng0494-394;
RA Ellis N.A., Ye T.Z., Patton S., German J., Goodfellow P.N., Weller P.;
RT "Cloning of PBDX, an MIC2-related gene that spans the pseudoautosomal
RT boundary on chromosome Xp.";
RL Nat. Genet. 6:394-400(1994).
RN [2]
RP NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 1).
RA Naoko S., Fujiki K., Kanai A., Tanaka Y., Iwata T.;
RT "Identification of PBDX gene highly expressed in human cornea.";
RL Submitted (MAY-2001) to the EMBL/GenBank/DDBJ databases.
RN [3]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RX PubMed=15772651; DOI=10.1038/nature03440;
RA Ross M.T., Grafham D.V., Coffey A.J., Scherer S., McLay K., Muzny D.,
RA Platzer M., Howell G.R., Burrows C., Bird C.P., Frankish A.,
RA Lovell F.L., Howe K.L., Ashurst J.L., Fulton R.S., Sudbrak R., Wen G.,
RA Jones M.C., Hurles M.E., Andrews T.D., Scott C.E., Searle S.,
RA Ramser J., Whittaker A., Deadman R., Carter N.P., Hunt S.E., Chen R.,
RA Cree A., Gunaratne P., Havlak P., Hodgson A., Metzker M.L.,
RA Richards S., Scott G., Steffen D., Sodergren E., Wheeler D.A.,
RA Worley K.C., Ainscough R., Ambrose K.D., Ansari-Lari M.A., Aradhya S.,
RA Ashwell R.I., Babbage A.K., Bagguley C.L., Ballabio A., Banerjee R.,
RA Barker G.E., Barlow K.F., Barrett I.P., Bates K.N., Beare D.M.,
RA Beasley H., Beasley O., Beck A., Bethel G., Blechschmidt K., Brady N.,
RA Bray-Allen S., Bridgeman A.M., Brown A.J., Brown M.J., Bonnin D.,
RA Bruford E.A., Buhay C., Burch P., Burford D., Burgess J., Burrill W.,
RA Burton J., Bye J.M., Carder C., Carrel L., Chako J., Chapman J.C.,
RA Chavez D., Chen E., Chen G., Chen Y., Chen Z., Chinault C.,
RA Ciccodicola A., Clark S.Y., Clarke G., Clee C.M., Clegg S.,
RA Clerc-Blankenburg K., Clifford K., Cobley V., Cole C.G., Conquer J.S.,
RA Corby N., Connor R.E., David R., Davies J., Davis C., Davis J.,
RA Delgado O., Deshazo D., Dhami P., Ding Y., Dinh H., Dodsworth S.,
RA Draper H., Dugan-Rocha S., Dunham A., Dunn M., Durbin K.J., Dutta I.,
RA Eades T., Ellwood M., Emery-Cohen A., Errington H., Evans K.L.,
RA Faulkner L., Francis F., Frankland J., Fraser A.E., Galgoczy P.,
RA Gilbert J., Gill R., Gloeckner G., Gregory S.G., Gribble S.,
RA Griffiths C., Grocock R., Gu Y., Gwilliam R., Hamilton C., Hart E.A.,
RA Hawes A., Heath P.D., Heitmann K., Hennig S., Hernandez J.,
RA Hinzmann B., Ho S., Hoffs M., Howden P.J., Huckle E.J., Hume J.,
RA Hunt P.J., Hunt A.R., Isherwood J., Jacob L., Johnson D., Jones S.,
RA de Jong P.J., Joseph S.S., Keenan S., Kelly S., Kershaw J.K., Khan Z.,
RA Kioschis P., Klages S., Knights A.J., Kosiura A., Kovar-Smith C.,
RA Laird G.K., Langford C., Lawlor S., Leversha M., Lewis L., Liu W.,
RA Lloyd C., Lloyd D.M., Loulseged H., Loveland J.E., Lovell J.D.,
RA Lozado R., Lu J., Lyne R., Ma J., Maheshwari M., Matthews L.H.,
RA McDowall J., McLaren S., McMurray A., Meidl P., Meitinger T.,
RA Milne S., Miner G., Mistry S.L., Morgan M., Morris S., Mueller I.,
RA Mullikin J.C., Nguyen N., Nordsiek G., Nyakatura G., O'dell C.N.,
RA Okwuonu G., Palmer S., Pandian R., Parker D., Parrish J.,
RA Pasternak S., Patel D., Pearce A.V., Pearson D.M., Pelan S.E.,
RA Perez L., Porter K.M., Ramsey Y., Reichwald K., Rhodes S.,
RA Ridler K.A., Schlessinger D., Schueler M.G., Sehra H.K.,
RA Shaw-Smith C., Shen H., Sheridan E.M., Shownkeen R., Skuce C.D.,
RA Smith M.L., Sotheran E.C., Steingruber H.E., Steward C.A., Storey R.,
RA Swann R.M., Swarbreck D., Tabor P.E., Taudien S., Taylor T.,
RA Teague B., Thomas K., Thorpe A., Timms K., Tracey A., Trevanion S.,
RA Tromans A.C., d'Urso M., Verduzco D., Villasana D., Waldron L.,
RA Wall M., Wang Q., Warren J., Warry G.L., Wei X., West A.,
RA Whitehead S.L., Whiteley M.N., Wilkinson J.E., Willey D.L.,
RA Williams G., Williams L., Williamson A., Williamson H., Wilming L.,
RA Woodmansey R.L., Wray P.W., Yen J., Zhang J., Zhou J., Zoghbi H.,
RA Zorilla S., Buck D., Reinhardt R., Poustka A., Rosenthal A.,
RA Lehrach H., Meindl A., Minx P.J., Hillier L.W., Willard H.F.,
RA Wilson R.K., Waterston R.H., Rice C.M., Vaudin M., Coulson A.,
RA Nelson D.L., Weinstock G., Sulston J.E., Durbin R.M., Hubbard T.,
RA Gibbs R.A., Beck S., Rogers J., Bentley D.R.;
RT "The DNA sequence of the human X chromosome.";
RL Nature 434:325-337(2005).
RN [4]
RP NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 1).
RA Naoko S., Tanaka Y., Iwata T.;
RL Submitted (AUG-2002) to the EMBL/GenBank/DDBJ databases.
RN [5]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] (ISOFORMS 1; 2 AND 3), AND
RP VARIANT ASN-60.
RX PubMed=15489334; DOI=10.1101/gr.2596504;
RG The MGC Project Team;
RT "The status, quality, and expansion of the NIH full-length cDNA
RT project: the Mammalian Gene Collection (MGC).";
RL Genome Res. 14:2121-2127(2004).
RN [6]
RP SUBCELLULAR LOCATION.
RX PubMed=7533029; DOI=10.1038/ng1194-285;
RA Ellis N.A., Tippett P., Petty A., Reid M., Weller P.A., Ye T.Z.,
RA German J., Goodfellow P.N., Thomas S., Banting G.;
RT "PBDX is the XG blood group gene.";
RL Nat. Genet. 8:285-290(1994).
RN [7]
RP TISSUE SPECIFICITY.
RX PubMed=10688843;
RA Fouchet C., Gane P., Huet M., Fellous M., Rouger P., Banting G.,
RA Cartron J.P., Lopez C.;
RT "A study of the coregulation and tissue specificity of XG and MIC2
RT gene expression in eukaryotic cells.";
RL Blood 95:1819-1826(2000).
CC -!- SUBCELLULAR LOCATION: Cell membrane; Single-pass type I membrane
CC protein.
CC -!- ALTERNATIVE PRODUCTS:
CC Event=Alternative splicing; Named isoforms=3;
CC Name=1;
CC IsoId=P55808-1; Sequence=Displayed;
CC Name=2;
CC IsoId=P55808-2; Sequence=VSP_037319;
CC Note=No experimental confirmation available;
CC Name=3;
CC IsoId=P55808-3; Sequence=VSP_037320;
CC Note=No experimental confirmation available. Ref.5 (AAI00766)
CC sequence is in conflict in position: 131:L->P;
CC -!- TISSUE SPECIFICITY: Expressed in erythroid tissues, including
CC thymus, bone marrow and fetal liver, and in several nonerythroid
CC tissues, such as heart, placenta, skeletal muscle, thyroid and
CC trachea, as well as in skin fibroblasts. Expression is low or
CC undetectable in other tissues.
CC -!- PTM: O-glycosylated (Probable).
CC -!- POLYMORPHISM: XG is responsible for the Xg blood group system.
CC -!- MISCELLANEOUS: The gene coding for this protein is located in the
CC pseudoautosomal region 1 (PAR1) of X and Y chromosomes.
CC -!- SIMILARITY: Belongs to the CD99 family.
CC -!- WEB RESOURCE: Name=dbRBC/BGMUT; Note=Blood group antigen gene
CC mutation database;
CC URL="http://www.ncbi.nlm.nih.gov/gv/mhc/xslcgi.cgi?cmd=bgmut/systems_info&system;=xg";
CC -----------------------------------------------------------------------
CC Copyrighted by the UniProt Consortium, see http://www.uniprot.org/terms
CC Distributed under the Creative Commons Attribution-NoDerivs License
CC -----------------------------------------------------------------------
DR EMBL; X96421; -; NOT_ANNOTATED_CDS; Genomic_DNA.
DR EMBL; AF380356; AAL04055.1; -; mRNA.
DR EMBL; AF534880; AAN03481.1; -; mRNA.
DR EMBL; AC006209; -; NOT_ANNOTATED_CDS; Genomic_DNA.
DR EMBL; AC138085; -; NOT_ANNOTATED_CDS; Genomic_DNA.
DR EMBL; BC100765; AAI00766.1; -; mRNA.
DR EMBL; BC100766; AAI00767.1; -; mRNA.
DR EMBL; BC100767; AAI00768.1; -; mRNA.
DR PIR; S43791; S43791.
DR RefSeq; NP_001135391.1; NM_001141919.1.
DR RefSeq; NP_001135392.1; NM_001141920.1.
DR RefSeq; NP_780778.1; NM_175569.2.
DR UniGene; Hs.179675; -.
DR ProteinModelPortal; P55808; -.
DR STRING; 9606.ENSP00000411004; -.
DR PhosphoSite; P55808; -.
DR DMDM; 2499136; -.
DR PaxDb; P55808; -.
DR PRIDE; P55808; -.
DR Ensembl; ENST00000381174; ENSP00000370566; ENSG00000124343.
DR Ensembl; ENST00000419513; ENSP00000411004; ENSG00000124343.
DR Ensembl; ENST00000426774; ENSP00000398503; ENSG00000124343.
DR GeneID; 7499; -.
DR KEGG; hsa:7499; -.
DR UCSC; uc011mhg.2; human.
DR CTD; 7499; -.
DR GeneCards; GC0XP002663; -.
DR H-InvDB; HIX0213635; -.
DR HGNC; HGNC:12806; XG.
DR HPA; HPA021539; -.
DR MIM; 300879; gene.
DR MIM; 314700; phenotype.
DR neXtProt; NX_P55808; -.
DR PharmGKB; PA37405; -.
DR eggNOG; NOG124417; -.
DR HOGENOM; HOG000233665; -.
DR HOVERGEN; HBG086239; -.
DR OMA; GGNIYPR; -.
DR OrthoDB; EOG780RPH; -.
DR ChiTaRS; XG; human.
DR GenomeRNAi; 7499; -.
DR NextBio; 29368; -.
DR PRO; PR:P55808; -.
DR ArrayExpress; P55808; -.
DR Bgee; P55808; -.
DR CleanEx; HS_XG; -.
DR Genevestigator; P55808; -.
DR GO; GO:0005887; C:integral to plasma membrane; IDA:UniProtKB.
DR InterPro; IPR022078; CD99L2.
DR Pfam; PF12301; CD99L2; 1.
PE 2: Evidence at transcript level;
KW Alternative splicing; Blood group antigen; Cell membrane;
KW Complete proteome; Glycoprotein; Membrane; Polymorphism;
KW Reference proteome; Signal; Transmembrane; Transmembrane helix.
FT SIGNAL 1 21 Potential.
FT CHAIN 22 180 Glycoprotein Xg.
FT /FTId=PRO_0000022693.
FT TOPO_DOM 22 142 Extracellular (Potential).
FT TRANSMEM 143 163 Helical; (Potential).
FT TOPO_DOM 164 180 Cytoplasmic (Potential).
FT VAR_SEQ 85 85 G -> GS (in isoform 2).
FT /FTId=VSP_037319.
FT VAR_SEQ 125 125 G -> GRGGYRLNSRYGNTYG (in isoform 3).
FT /FTId=VSP_037320.
FT VARIANT 60 60 D -> N (in dbSNP:rs5939319).
FT /FTId=VAR_054063.
SQ SEQUENCE 180 AA; 19723 MW; DADAA9E6859C4530 CRC64;
MESWWGLPCL AFLCFLMHAR GQRDFDLADA LDDPEPTKKP NSDIYPKPKP PYYPQPENPD
SGGNIYPRPK PRPQPQPGNS GNSGGYFNDV DRDDGRYPPR PRPRPPAGGG GGGYSSYGNS
DNTHGGDHHS TYGNPEGNMV AKIVSPIVSV VVVTLLGAAA SYFKLNNRRN CFRTHEPENV
//
MIM
300879
*RECORD*
*FIELD* NO
300879
*FIELD* TI
*300879 XG GLYCOPROTEIN; XG
;;PBDX
*FIELD* TX
CLONING
Ellis et al. (1994) identified XG, which they called PBDX, as the gene
read moreencoding the Xg(a) antigen of the XG blood group (314700). Using rabbit
polyclonal and mouse monoclonal antibodies raised against a peptide
derived from the N-terminal domain of the predicted mature PBDX protein,
they identified the Xg(a) antigen. By its identity with PBDX, therefore,
Xg(a) was recognized as a cell-surface antigen 48% homologous to CD99
(313470), which is encoded in the tightly linked MIC2 gene. Northern
blot and RT-PCR analyses detected PBDX expression in hematopoietic
tissues, including umbilical cord, adult bone marrow, and fetal liver,
thymus, and spleen, as well as in cultured skin fibroblasts. Expression
was low or undetectable in all other tissues and cell lines examined.
Immunoblot analysis using anti-Xg(a) as probe detected bands with
apparent molecular masses from 24 to 29 kD in membrane lysates from
Xg(a)-positive, but not Xg(a)-negative, erythrocytes.
By Northern blot analysis of human tissues, Fouchet et al. (2000)
detected major XG transcripts of 2.3 and 1.0 kb and a minor transcript
of 3.8 kb in erythroid tissues, including thymus, bone marrow, and fetal
liver, and several nonerythroid tissues, including heart, placenta,
skeletal muscle, prostate, thyroid, spinal cord, and trachea. RT-PCR
also detected XG expression in adult lung, kidney, and testis and in
fetal spleen, adrenal gland, brain, pancreas, and small intestine.
Western blot analysis of human erythrocytes, transfected mouse cells,
and somatic hybrids revealed a 26-kD XG protein.
GENE FUNCTION
Goodfellow et al. (1987) presented evidence suggesting the existence of
a pseudoautosomal locus, XGR (314705), that regulates expression of MIC2
and XG.
Ellis et al. (1994) concluded that the XG polymorphism of the XG blood
group system is defined by a difference in the level of the Xg antigen
on the surface of the erythrocyte rather than a difference in the amino
acid sequences of the protein products encoded by the Xg(a) allele and
an alternative Xg(a)-negative allele. They proposed a model in which the
observed XG polymorphism may be due to variation in XGR, which may be
situated between the XG locus proximally and the MIC2 locus distally.
Using flow cytometry and Western and Northern blot analyses, Fouchet et
al. (2000) provided a quantitative estimation of XG and CD99 on human
erythrocytes. Their findings supported the hypothesis of genetic control
of XG and CD99 expression by the hypothetical XGR locus.
Fouchet et al. (2000) examined coexpression of human XG and CD99 cDNAs
in transfected mouse cells, either in double transfectants or in somatic
hybrids from single transfectants. Their findings were consistent with
transcriptional coregulation of XG and CD99 expression, because no
influence of either protein on the surface production of the other was
observed. In addition, Fouchet et al. (2000) found no evidence of
association or complex formation between XG and CD99 on transfected
mouse cells or human erythrocytes.
GENE STRUCTURE
In her review of the XG blood group system, Johnson (2011) stated that
the XG gene contains 10 exons.
MAPPING
In her review of the XG blood group system, Johnson (2011) stated that
the XG gene spans the pseudoautosomal boundary between the 2 regions of
the X chromosome at Xp22.3; exons 1 to 3 are located in the
pseudoautosomal region, and exons 4 to 10 are located in the sex
chromosome-specific region. The MIC2 gene, which encodes CD99, is
located in the pseudoautosomal region at chromosome Xp22.2, adjacent to
the XG gene.
Ellis et al. (1994) stated that the XG and MIC2 genes are arranged head
to tail on distal Xp, with the last exon of MIC2 separated from the
first exon of XG by less than 10 kb.
- Pseudogenes
Transcription from the XG promoter on the Y chromosome has been detected
by cDNA cloning and PCR-based methods. An expressed pseudogene of XG,
designated XGPY1, maps to interval Yq11.21 (Weller et al., 1995). XGPY1
is transcribed and subject to alternative splicing. Sequence comparison
suggested that XGPY1 originated from XG by a gene duplication event in
the primate lineage.
EVOLUTION
Yi et al. (2004) studied the rates of nucleotide substitution in 8
introns of the human and great ape XG gene, which spans the boundary
between pseudoautosomal region-1 (PAR1) and X-specific region. They
found that PAR1 introns of XG had evolved more slowly than X-specific
introns. Only when a New World monkey was compared with hominoids were
the rates slightly increased in PAR1 introns. Although the intergenic
regions of human PAR1 showed a significant increase in G and C
nucleotides, the base composition of the surveyed PAR1 introns was
similar to that of X-specific introns. Evidence indicated that the
recombination rate was much higher in PAR1 introns than X-specific
introns and that the present pseudoautosomal boundary has persisted
since the common ancestor of hominoids. Yi et al. (2004) concluded that
the mutagenic effect of recombination is far weaker than previously
thought, at least in hominoid pseudoautosomal boundaries.
*FIELD* RF
1. Ellis, N. A.; Tippett, P.; Petty, A.; Reid, M.; Weller, P. A.;
Ye, T. Z.; German, J.; Goodfellow, P. N.; Thomas, S.; Banting, G.
: PBDX is the XG blood group gene. Nature Genet. 8: 285-290, 1994.
2. Fouchet, C.; Gane, P.; Cartron, J.-P.; Lopez, C.: Quantitative
analysis of XG blood group and CD99 antigens on human red cells. Immunogenetics 51:
688-694, 2000.
3. Fouchet, C.; Gane, P.; Huet, M.; Fellous, M.; Rouger, P.; Banting,
G.; Cartron, J.-P.; Lopez, C. A study of the coregulation and tissue
specificity of XG and MIC2 gene expression in eukaryotic cells. Blood 95:
1819-1826, 2000.
4. Goodfellow, P. J.; Pritchard, C.; Tippett, P.; Goodfellow, P. N.
: Recombination between the X and Y chromosomes: implications for
the relationship between MIC2, XG and YG. Ann. Hum. Genet. 51: 161-167,
1987.
5. Johnson, N. C.: XG: the forgotten blood group system. Immunohematology 27:
68-71, 2011.
6. Weller, P. A.; Critcher, R.; Goodfellow, P. N.; German, J.; Ellis,
N. A.: The human Y chromosome homologue of XG: transcription of a
naturally truncated gene. Hum. Molec. Genet. 4: 859-868, 1995.
7. Yi, S.; Summers, T. J.; Pearson, N. M.; Li, W.-H.: Recombination
has little effect on the rate of sequence divergence in pseudoautosomal
boundary 1 among humans and great apes. Genome Res. 14: 37-43, 2004.
*FIELD* CD
Matthew B. Gross: 9/11/2012
*FIELD* ED
mgross: 09/11/2012
mgross: 9/11/2012
*RECORD*
*FIELD* NO
300879
*FIELD* TI
*300879 XG GLYCOPROTEIN; XG
;;PBDX
*FIELD* TX
CLONING
Ellis et al. (1994) identified XG, which they called PBDX, as the gene
read moreencoding the Xg(a) antigen of the XG blood group (314700). Using rabbit
polyclonal and mouse monoclonal antibodies raised against a peptide
derived from the N-terminal domain of the predicted mature PBDX protein,
they identified the Xg(a) antigen. By its identity with PBDX, therefore,
Xg(a) was recognized as a cell-surface antigen 48% homologous to CD99
(313470), which is encoded in the tightly linked MIC2 gene. Northern
blot and RT-PCR analyses detected PBDX expression in hematopoietic
tissues, including umbilical cord, adult bone marrow, and fetal liver,
thymus, and spleen, as well as in cultured skin fibroblasts. Expression
was low or undetectable in all other tissues and cell lines examined.
Immunoblot analysis using anti-Xg(a) as probe detected bands with
apparent molecular masses from 24 to 29 kD in membrane lysates from
Xg(a)-positive, but not Xg(a)-negative, erythrocytes.
By Northern blot analysis of human tissues, Fouchet et al. (2000)
detected major XG transcripts of 2.3 and 1.0 kb and a minor transcript
of 3.8 kb in erythroid tissues, including thymus, bone marrow, and fetal
liver, and several nonerythroid tissues, including heart, placenta,
skeletal muscle, prostate, thyroid, spinal cord, and trachea. RT-PCR
also detected XG expression in adult lung, kidney, and testis and in
fetal spleen, adrenal gland, brain, pancreas, and small intestine.
Western blot analysis of human erythrocytes, transfected mouse cells,
and somatic hybrids revealed a 26-kD XG protein.
GENE FUNCTION
Goodfellow et al. (1987) presented evidence suggesting the existence of
a pseudoautosomal locus, XGR (314705), that regulates expression of MIC2
and XG.
Ellis et al. (1994) concluded that the XG polymorphism of the XG blood
group system is defined by a difference in the level of the Xg antigen
on the surface of the erythrocyte rather than a difference in the amino
acid sequences of the protein products encoded by the Xg(a) allele and
an alternative Xg(a)-negative allele. They proposed a model in which the
observed XG polymorphism may be due to variation in XGR, which may be
situated between the XG locus proximally and the MIC2 locus distally.
Using flow cytometry and Western and Northern blot analyses, Fouchet et
al. (2000) provided a quantitative estimation of XG and CD99 on human
erythrocytes. Their findings supported the hypothesis of genetic control
of XG and CD99 expression by the hypothetical XGR locus.
Fouchet et al. (2000) examined coexpression of human XG and CD99 cDNAs
in transfected mouse cells, either in double transfectants or in somatic
hybrids from single transfectants. Their findings were consistent with
transcriptional coregulation of XG and CD99 expression, because no
influence of either protein on the surface production of the other was
observed. In addition, Fouchet et al. (2000) found no evidence of
association or complex formation between XG and CD99 on transfected
mouse cells or human erythrocytes.
GENE STRUCTURE
In her review of the XG blood group system, Johnson (2011) stated that
the XG gene contains 10 exons.
MAPPING
In her review of the XG blood group system, Johnson (2011) stated that
the XG gene spans the pseudoautosomal boundary between the 2 regions of
the X chromosome at Xp22.3; exons 1 to 3 are located in the
pseudoautosomal region, and exons 4 to 10 are located in the sex
chromosome-specific region. The MIC2 gene, which encodes CD99, is
located in the pseudoautosomal region at chromosome Xp22.2, adjacent to
the XG gene.
Ellis et al. (1994) stated that the XG and MIC2 genes are arranged head
to tail on distal Xp, with the last exon of MIC2 separated from the
first exon of XG by less than 10 kb.
- Pseudogenes
Transcription from the XG promoter on the Y chromosome has been detected
by cDNA cloning and PCR-based methods. An expressed pseudogene of XG,
designated XGPY1, maps to interval Yq11.21 (Weller et al., 1995). XGPY1
is transcribed and subject to alternative splicing. Sequence comparison
suggested that XGPY1 originated from XG by a gene duplication event in
the primate lineage.
EVOLUTION
Yi et al. (2004) studied the rates of nucleotide substitution in 8
introns of the human and great ape XG gene, which spans the boundary
between pseudoautosomal region-1 (PAR1) and X-specific region. They
found that PAR1 introns of XG had evolved more slowly than X-specific
introns. Only when a New World monkey was compared with hominoids were
the rates slightly increased in PAR1 introns. Although the intergenic
regions of human PAR1 showed a significant increase in G and C
nucleotides, the base composition of the surveyed PAR1 introns was
similar to that of X-specific introns. Evidence indicated that the
recombination rate was much higher in PAR1 introns than X-specific
introns and that the present pseudoautosomal boundary has persisted
since the common ancestor of hominoids. Yi et al. (2004) concluded that
the mutagenic effect of recombination is far weaker than previously
thought, at least in hominoid pseudoautosomal boundaries.
*FIELD* RF
1. Ellis, N. A.; Tippett, P.; Petty, A.; Reid, M.; Weller, P. A.;
Ye, T. Z.; German, J.; Goodfellow, P. N.; Thomas, S.; Banting, G.
: PBDX is the XG blood group gene. Nature Genet. 8: 285-290, 1994.
2. Fouchet, C.; Gane, P.; Cartron, J.-P.; Lopez, C.: Quantitative
analysis of XG blood group and CD99 antigens on human red cells. Immunogenetics 51:
688-694, 2000.
3. Fouchet, C.; Gane, P.; Huet, M.; Fellous, M.; Rouger, P.; Banting,
G.; Cartron, J.-P.; Lopez, C. A study of the coregulation and tissue
specificity of XG and MIC2 gene expression in eukaryotic cells. Blood 95:
1819-1826, 2000.
4. Goodfellow, P. J.; Pritchard, C.; Tippett, P.; Goodfellow, P. N.
: Recombination between the X and Y chromosomes: implications for
the relationship between MIC2, XG and YG. Ann. Hum. Genet. 51: 161-167,
1987.
5. Johnson, N. C.: XG: the forgotten blood group system. Immunohematology 27:
68-71, 2011.
6. Weller, P. A.; Critcher, R.; Goodfellow, P. N.; German, J.; Ellis,
N. A.: The human Y chromosome homologue of XG: transcription of a
naturally truncated gene. Hum. Molec. Genet. 4: 859-868, 1995.
7. Yi, S.; Summers, T. J.; Pearson, N. M.; Li, W.-H.: Recombination
has little effect on the rate of sequence divergence in pseudoautosomal
boundary 1 among humans and great apes. Genome Res. 14: 37-43, 2004.
*FIELD* CD
Matthew B. Gross: 9/11/2012
*FIELD* ED
mgross: 09/11/2012
mgross: 9/11/2012
MIM
314700
*RECORD*
*FIELD* NO
314700
*FIELD* TI
314700 BLOOD GROUP, XG SYSTEM; XG
;;XG BLOOD GROUP SYSTEM
*FIELD* TX
DESCRIPTION
read moreThe XG blood group system is the only blood group system assigned to the
X chromosome. The system consists of 2 antigens, Xg(a) and CD99, which
are encoded by 2 adjacent genes, XG and CD99 (313470). Xg(a) may be
expressed only on red blood cells, whereas CD99 is expressed on all
tissue cells. The expression level of CD99 on red blood cells is
directly related to the presence or absence of Xg(a). Both anti-Xg(a)
and anti-CD99 are rare. Anti-Xg(a) is considered clinically
insignificant, and the clinical significance of anti-CD99 is unknown
(review by Johnson, 2011).
CLINICAL FEATURES
Mann et al. (1962) identified the first Xg(a) antiserum in a patient
with hereditary hemorrhagic telangiectasia (see 187300) who had received
many transfusions (Mann et al., 1962). The antigen is well developed at
birth. Evidence suggested that homozygotes react as strongly with
anti-Xg(a) as hemizygotes and more strongly than heterozygotes.
INHERITANCE
Mann et al. (1962) demonstrated that the Xg(a) antigen behaves as an
X-linked dominant.
POPULATION GENETICS
Mann et al. (1962) found the Xg(a) antigen in 89% of 188 Caucasian
females and in 62% of 154 males. In the few Blacks tested, the phenotype
frequencies seem to be about the same as in Caucasians.
The efficient estimate of the frequency of the Xg(a) allele in
Caucasians, making use of the data on females as well as males, is 0.651
(Sanger et al., 1962).
MAPPING
In her review, Johnson (2011) stated that the XG gene, which encodes
Xg(a), spans the pseudoautosomal boundary between the 2 regions of the X
chromosome at Xp22.3. The MIC2 gene, which encodes CD99, is located in
the pseudoautosomal region at chromosome Xp22.2, adjacent to the XG
gene.
Ellis et al. (1994) proposed that the observed XG polymorphism may be
due to variation in an XG regulator (XGR; 314705) that may be situated
between the XG gene and the MIC2 gene (see MOLECULAR GENETICS).
MOLECULAR GENETICS
Ellis et al. (1994) demonstrated that XG, which they called PBDX, a gene
found to span the pseudoautosomal boundary on the X chromosome, is the
XG blood group gene. Using rabbit polyclonal and mouse monoclonal
antibodies raised against a peptide derived from the N-terminal domain
of the predicted mature PBDX, they identified the Xg(a) antigen. By its
identity with PBDX, therefore, Xg(a) was recognized as a cell-surface
antigen 48% homologous to CD99. Ellis et al. (1994) concluded that the
XG polymorphism is defined by a difference in the level of the Xg
antigen on the surface of the erythrocyte rather than a difference in
the amino acid sequences of the protein products encoded by the Xg(a)
allele and an alternative Xg(a)-negative allele. They proposed a model
in which the observed XG polymorphism may be due to variation in an XG
regulator (XGR; 314705) that may be situated between the XG locus
proximally and the MIC2 locus distally.
Data on gene frequencies of XG allelic variants were tabulated by
Roychoudhury and Nei (1988).
HISTORY
The Xg(a) blood group proved useful to genetics, especially for study of
linkage (summary by Race and Sanger, 1975) and determination where
nondisjunction occurs leading to X chromosome aneuploidy. Evidence on
lyonization of the Xg locus was conflicting. Evidence for lyonization
came from a study of X-linked hypochromic anemia (300751) by Lee et al.
(1968). Lawler and Sanger (1970) found that a group of females with
Philadelphia-chromosome-positive myeloid leukemia cases had the
frequency of Xg types expected of females. This could mean either that
the Xg locus is not subject to inactivation or that all Ph-positive
cells are not monoclonal. Also assumed, of course, was that the
erythroid cells in the patients studied were derived from a Ph-positive
cell and that no red cells derived from Ph-negative precursors
persisted. Data on linkage of the Xg locus with many other loci are
summarized by Race and Sanger (1975). Ducos et al. (1971) studied a
chimera twin pair in whom 2 red cell populations were easily separable
because of differences in their ABO blood groups. One population was
Xg(a+), the other Xg(a-). Thus the important point was established that
the Xg antigen is made in the red cell precursors and not secondarily
acquired by red cells. Xg can, therefore, give information on
lyonization.
The Xg locus cannot be on the distal third of the long arm of the X
chromosome, because Pearson (1973) observed a family in which the mother
was Xg(a+) and had a balanced translocation of the distal third of the
Xq onto 3p, the karyologically normal father was Xg(a-), and an
unbalanced daughter with deleted distal third of the long arm of one X
chromosome (derived from the mother) was Xg(a+). Bernstein et al. (1977)
presented evidence from an X-Y translocation suggesting that the Xg
locus is at the distal end of Xp and that an X-linked mental retardation
locus is in the same region. From the study of a boy nullisomic for the
terminal portion of Xp, Ferguson-Smith and Aitken (1982) concluded that
the order of loci is STS (300747)--11cM--Xg--?2cM--Xk--OA. The boy
showed sulfatase-deficient ichthyosis and was Xg(a-), although the
family findings suggest that he should be Xg(a+), but he did not have
chronic granulomatous disease or ocular albinism. On the other hand,
Ropers et al. (1982) suggested the order Xg--H-Y repressor--STS--Xk.
That the Xg locus is near one end of the X chromosome was suggested by
the fact that it shows lack of linkage with so many loci. (The genetic
length of the X chromosome is about 200 cM.) Race and Sanger (1975)
pointed out that when the 3-generation linkage data for deutan (303800),
protan (303900), G6PD (305900) and classic hemophilia (306700) (on the
one hand) versus Xg (on the other) are pooled, the score is 236
nonrecombinants and 193 recombinants: a recombination fraction of 45%
(chi square 4.3, expecting 50% recombination).
Positive evidence that Xg is in the Xp2 region comes mainly from 2
sources. In the first place, Evans et al. (1979) reported morphologic
studies suggesting that about 70% of nonmosaic cases of XX males have
arisen by Xp-Yp interchange in paternal meiosis. In such cases, the
short arm of one X is longer, by 0.4% to 22.9%, than the short arm of
the other X chromosome, and its banding profile is altered. Evans et al.
(1979) found a Y-specific fragment in the DNA digest from 1 of 3 XX
males with Xp+ whom they studied. Combined with this morphologic and
biochemical evidence for Xp-Yp interchange are the data on Xg blood
group in XX males and their parents. In 9 of 12 cases the XX male failed
to inherit the Xg+ gene from his father, suggesting that the Xg locus
was lost in the process of Xp-Yp interchange. These cases were not
studied morphologically; thus the cases without anomaly of Xg
inheritance may have had a cause other than interchange, e.g., occult
mosaicism, transfer of Y material to an autosome, or perhaps an
autosomal recessive gene for sex reversal. (De la Chapelle et al. (1979)
could not corroborate heteromorphism of the X chromosomes in 46,XX
males.) During meiosis the X and Y chromosomes show terminal association
of their short arms, including an electron microscopically demonstrable
synaptinemal complex. This may predispose to X-Y interchange. There
should be XY individuals who are Xg-positive, even though the mother is
Xg-negative, as a result of transfer of their father's Xg+ gene to the Y
chromosome that he gave that particular offspring. Such persons might or
might not have an abnormality of sexual development.
A second web of evidence that Xg is on Xp2 comprises (a) the linkage of
Xg to X-linked ichthyosis (308100), (b) the demonstration of steroid
sulfatase deficiency as the fundamental defect in X-linked ichthyosis,
and (c) the assignment of the steroid sulfatase locus to Xp22-Xpter by
study of deleted X chromosomes in mouse-man somatic cell hybrids
(Mohandas et al., 1980). Both the Xg locus (Race and Sanger, 1975) and
the steroid sulfatase locus (Mohandas et al., 1980) do not, it seems,
participate in lyonization. Thus, the distal part of the short arm of
the X chromosome appears to have 2 properties different from the rest of
the X: pairing with the Y and absence of inactivation. Boyd et al.
(1981) studied an instructive family in which the Xg(a-) mother had a
46Xt(X;Y)(p24;q11) karyotype and had transmitted her X-Y translocation
chromosome to both her son and her daughter. The mother and daughter
were monosomic for the region Xq24-Xqter and the son nullisomic for the
same region. The maternal grandfather was Xg(a+) and neither grandparent
carried the translocation chromosome. Thus, in origin of the
translocation, the Xg locus was lost. The son showed generalized
ichthyosis and zero steroid sulfatase activity. His mother had activity
like that of normal males. Thus, the STS locus must have been involved
also in the deletion of Xp. Ferguson-Smith et al. (1964) had predicted,
on the basis of karyotype-phenotype correlations, that a region of Xp
must escape inactivation and contain the Xg locus. Ropers et al. (1983)
estimated the genetic length of the short arm of the X chromosome to be
about 75-90 cM (the Xg-centromere segment). Sarfarazi et al. (1983)
found no linkage between Xg and a proximal Xp DNA polymorphic marker
called L1.28 (DXS7) and no close linkage between Xg and a more distal
RFLP (lambda-RC8, or DXS9). Curry et al. (1984) found that the steroid
sulfatase, Xg, and MIC2X loci as well as the locus for X-linked
chondrodysplasia punctata (302950) were apparently absent in males with
deletion of Xp22.32.
*FIELD* SA
Boyd et al. (1981); Cook et al. (1963); Ellis et al. (1994); Goodfellow
and Tippett (1981); Marsh (1978); Nakajima et al. (1979); Sanger
et al. (1977); Siniscalco et al. (1966)
*FIELD* RF
1. Bernstein, R.; Wagner, J.; Jenkins, T.; Nurse, G. T.: X-Y translocation
in a mentally retarded XXY male child: possible localization of the
Xg locus. (Abstract) Vth Int. Conf. on Birth Defects, Montreal ,
8/1977.
2. Boyd, E.; Ferguson-Smith, M. A.; Ferguson-Smith, M. E.; Jamieson,
M. E.; Russell, J. E.; Aitken, D. A.; Sanger, R.; Tippett, P.: A
case of X;Y translocation which maps the Xg locus to Xp24-pter. (Abstract) J.
Med. Genet. 18: 224 only, 1981.
3. Boyd, E.; Ferguson-Smith, M. A.; Sanger, R.; Tippett, P.; Aitken,
D. A.: A familial X-Y translocation which assigns the Xg blood group
locus to the region Xp24-pter. (Abstract) Sixth Int. Cong. Hum. Genet.,
Jerusalem 150 only, 1981.
4. Cook, I. A.; Polley, M. J.; Mollison, P. L.: A second example
of anti-Xg(a). Lancet 281: 857-859, 1963. Note: Originally Volume
I.
5. Curry, C. J. R.; Magenis, R. E.; Brown, M.; Lanman, J. T., Jr.;
Tsai, J.; O'Lague, P.; Goodfellow, P.; Mohandas, T.; Bergner, E. A.;
Shapiro, L. J.: Inherited chondrodysplasia punctata due to a deletion
of the terminal short arm of an X chromosome. New Eng. J. Med. 311:
1010-1015, 1984.
6. de la Chapelle, A.; Simola, K.; Simola, P.; Knuutila, S.; Gahmberg,
N.; Pajunen, L.; Lundqvist, C.; Sarna, S.; Murros, J.: Heteromorphic
X chromosomes in 46,XX males? Hum. Genet. 52: 157-167, 1979.
7. Ducos, J.; Morty, Y.; Sanger, R.; Race, R. R.: Xg and X chromosome
inactivation. Lancet 298: 219-220, 1971. Note: Originally Volume
II.
8. Ellis, N. A.; Tippett, P.; Petty, A.; Reid, M.; German, J.; Goodfellow,
P. N.; Thomas, S.; Banting, G.: Identification of the XG blood group
gene. (Abstract) Am. J. Hum. Genet. 55 (suppl.): A14 only, 1994.
9. Ellis, N. A.; Tippett, P.; Petty, A.; Reid, M.; Weller, P. A.;
Ye, T. Z.; German, J.; Goodfellow, P. N.; Thomas, S.; Banting, G.
: PBDX is the XG blood group gene. Nature Genet. 8: 285-290, 1994.
10. Evans, H. J.; Buckton, K. E.; Spowart, G.; Carothers, A. D.:
Heteromorphic X chromosomes in 46,XX males: evidence for the involvement
of X-Y interchange. Hum. Genet. 49: 11-31, 1979.
11. Ferguson-Smith, M. A.; Aitken, D. A.: The contribution of chromosome
aberrations to the precision of human gene mapping. Cytogenet. Cell
Genet. 32: 24-42, 1982.
12. Ferguson-Smith, M. A.; Alexander, D. S.; Bowen, P.; Goodman, R.
M.; Kaufman, B. N.; Jones, H. W., Jr.; Heller, R. H.: Clinical and
cytogenetical studies in female gonadal dysgenesis and their bearing
on the cause of Turner's syndrome. Cytogenetics 3: 355-383, 1964.
13. Goodfellow, P. N.; Tippett, P.: A human quantitative polymorphism
related to Xg blood groups. Nature 289: 404-405, 1981.
14. Johnson, N. C.: XG: the forgotten blood group system. Immunohematology 27:
68-71, 2011.
15. Lawler, S. D.; Sanger, R.: Xg blood-groups and clonal-origin
theory of chronic myeloid leukaemia. Lancet 295: 584-585, 1970.
Note: Originally Volume I.
16. Lee, G. R.; MacDiarmid, W. D.; Cartwright, G. E.; Wintrobe, M.
M.: Hereditary, X-linked, sideroachrestic anemia: the isolation of
two erythrocyte populations differing in XgA blood type and porphyrin
content. Blood 32: 59-70, 1968.
17. Mann, J. D.; Cahan, A.; Gelb, A. G.; Fisher, N.; Hamper, J.; Tippett,
P.; Sanger, R.; Race, R. R.: A sex-linked blood group. Lancet 279:
8-10, 1962. Note: Originally Volume I.
18. Marsh, W. L.: Linkage of the Xg and Xk loci. Cytogenet. Cell
Genet. 22: 531-533, 1978.
19. Mohandas, T.; Shapiro, L. J.; Sparkes, R. S.; Sparkes, M. C.:
Regional assignment of the steroid sulfatase-X-linked ichthyosis locus:
implications for a non-inactivated region on the short arm of the
human X-chromosome. Proc. Nat. Acad. Sci. 76: 5779-5783, 1980.
20. Nakajima, H.; Murato, S.; Seno, T.: Three additional examples
of anti-Xg(a) and Xg blood groups among the Japanese. Transfusion 19:
480-481, 1979.
21. Pearson, P. L.: Personal Communication. Leiden, The Netherlands
1973.
22. Race, R. R.; Sanger, R.: Blood Groups in Man. Oxford: Blackwell
(pub.) (6th ed.): 1975.
23. Ropers, H.-H.; Wieacker, P.; Wienker, T. F.; Davies, K.; Williamson,
R.: On the genetic length of the short arm of the human X chromosome. Hum.
Genet. 65: 53-55, 1983.
24. Ropers, H. H.; Muller, C. R.; Fraccaro, M.: Steroid sulfatase:
gene dosage studies in X chromosome aberrations and XX males. (Abstract) Cytogenet.
Cell Genet. 32: 311 only, 1982.
25. Roychoudhury, A. K.; Nei, M.: Human Polymorphic Genes: World
Distribution. New York: Oxford Univ. Press (pub.) 1988.
26. Sanger, R.; Race, R. R.; Tippett, P.; Hamper, J.; Gavin, J.; Cleghorn,
T. E.: The X-linked blood group system Xg: more tests on unrelated
people and on families. Vox Sang. 7: 571-578, 1962.
27. Sanger, R.; Tippett, P.; Gavin, J.; Teesdale, P.; Daniels, G.
L.: Xg groups and sex chromosome abnormalities in people of Northern
European ancestry: an addendum. J. Med. Genet. 14: 210-211, 1977.
28. Sarfarazi, M.; Harper, P. S.; Kingston, H. M.; Murray, J. M.;
O'Brien, T.; Davies, K. E.; Williamson, R.; Tippett, P.; Sanger, R.
: Genetic linkage relationships between the Xg blood group system
and two X chromosome DNA polymorphisms in families with Duchenne and
Becker muscular dystrophy. Hum. Genet. 65: 169-171, 1983.
29. Siniscalco, M.; Filippi, G.; Latte, B.; Piomelli, S.; Rattazzi,
M.; Gavin, J.; Sanger, R.; Race, R. R.: Failure to detect linkage
between Xg and X-borne loci in Sardinians. Ann. Hum. Genet. 29:
231-252, 1966.
*FIELD* CN
Matthew B. Gross - updated: 9/11/2012
Victor A. McKusick - edited: 3/10/1997
*FIELD* CD
Victor A. McKusick: 6/4/1986
*FIELD* ED
mgross: 09/11/2012
mgross: 9/11/2012
alopez: 3/2/2012
carol: 9/14/2010
terry: 3/31/2009
carol: 11/4/2008
carol: 10/31/2008
terry: 8/26/2008
carol: 4/29/2004
carol: 3/18/2004
terry: 3/13/2001
mark: 3/10/1997
mark: 6/12/1995
terry: 12/5/1994
davew: 8/22/1994
warfield: 4/20/1994
mimadm: 4/18/1994
carol: 11/24/1993
*RECORD*
*FIELD* NO
314700
*FIELD* TI
314700 BLOOD GROUP, XG SYSTEM; XG
;;XG BLOOD GROUP SYSTEM
*FIELD* TX
DESCRIPTION
read moreThe XG blood group system is the only blood group system assigned to the
X chromosome. The system consists of 2 antigens, Xg(a) and CD99, which
are encoded by 2 adjacent genes, XG and CD99 (313470). Xg(a) may be
expressed only on red blood cells, whereas CD99 is expressed on all
tissue cells. The expression level of CD99 on red blood cells is
directly related to the presence or absence of Xg(a). Both anti-Xg(a)
and anti-CD99 are rare. Anti-Xg(a) is considered clinically
insignificant, and the clinical significance of anti-CD99 is unknown
(review by Johnson, 2011).
CLINICAL FEATURES
Mann et al. (1962) identified the first Xg(a) antiserum in a patient
with hereditary hemorrhagic telangiectasia (see 187300) who had received
many transfusions (Mann et al., 1962). The antigen is well developed at
birth. Evidence suggested that homozygotes react as strongly with
anti-Xg(a) as hemizygotes and more strongly than heterozygotes.
INHERITANCE
Mann et al. (1962) demonstrated that the Xg(a) antigen behaves as an
X-linked dominant.
POPULATION GENETICS
Mann et al. (1962) found the Xg(a) antigen in 89% of 188 Caucasian
females and in 62% of 154 males. In the few Blacks tested, the phenotype
frequencies seem to be about the same as in Caucasians.
The efficient estimate of the frequency of the Xg(a) allele in
Caucasians, making use of the data on females as well as males, is 0.651
(Sanger et al., 1962).
MAPPING
In her review, Johnson (2011) stated that the XG gene, which encodes
Xg(a), spans the pseudoautosomal boundary between the 2 regions of the X
chromosome at Xp22.3. The MIC2 gene, which encodes CD99, is located in
the pseudoautosomal region at chromosome Xp22.2, adjacent to the XG
gene.
Ellis et al. (1994) proposed that the observed XG polymorphism may be
due to variation in an XG regulator (XGR; 314705) that may be situated
between the XG gene and the MIC2 gene (see MOLECULAR GENETICS).
MOLECULAR GENETICS
Ellis et al. (1994) demonstrated that XG, which they called PBDX, a gene
found to span the pseudoautosomal boundary on the X chromosome, is the
XG blood group gene. Using rabbit polyclonal and mouse monoclonal
antibodies raised against a peptide derived from the N-terminal domain
of the predicted mature PBDX, they identified the Xg(a) antigen. By its
identity with PBDX, therefore, Xg(a) was recognized as a cell-surface
antigen 48% homologous to CD99. Ellis et al. (1994) concluded that the
XG polymorphism is defined by a difference in the level of the Xg
antigen on the surface of the erythrocyte rather than a difference in
the amino acid sequences of the protein products encoded by the Xg(a)
allele and an alternative Xg(a)-negative allele. They proposed a model
in which the observed XG polymorphism may be due to variation in an XG
regulator (XGR; 314705) that may be situated between the XG locus
proximally and the MIC2 locus distally.
Data on gene frequencies of XG allelic variants were tabulated by
Roychoudhury and Nei (1988).
HISTORY
The Xg(a) blood group proved useful to genetics, especially for study of
linkage (summary by Race and Sanger, 1975) and determination where
nondisjunction occurs leading to X chromosome aneuploidy. Evidence on
lyonization of the Xg locus was conflicting. Evidence for lyonization
came from a study of X-linked hypochromic anemia (300751) by Lee et al.
(1968). Lawler and Sanger (1970) found that a group of females with
Philadelphia-chromosome-positive myeloid leukemia cases had the
frequency of Xg types expected of females. This could mean either that
the Xg locus is not subject to inactivation or that all Ph-positive
cells are not monoclonal. Also assumed, of course, was that the
erythroid cells in the patients studied were derived from a Ph-positive
cell and that no red cells derived from Ph-negative precursors
persisted. Data on linkage of the Xg locus with many other loci are
summarized by Race and Sanger (1975). Ducos et al. (1971) studied a
chimera twin pair in whom 2 red cell populations were easily separable
because of differences in their ABO blood groups. One population was
Xg(a+), the other Xg(a-). Thus the important point was established that
the Xg antigen is made in the red cell precursors and not secondarily
acquired by red cells. Xg can, therefore, give information on
lyonization.
The Xg locus cannot be on the distal third of the long arm of the X
chromosome, because Pearson (1973) observed a family in which the mother
was Xg(a+) and had a balanced translocation of the distal third of the
Xq onto 3p, the karyologically normal father was Xg(a-), and an
unbalanced daughter with deleted distal third of the long arm of one X
chromosome (derived from the mother) was Xg(a+). Bernstein et al. (1977)
presented evidence from an X-Y translocation suggesting that the Xg
locus is at the distal end of Xp and that an X-linked mental retardation
locus is in the same region. From the study of a boy nullisomic for the
terminal portion of Xp, Ferguson-Smith and Aitken (1982) concluded that
the order of loci is STS (300747)--11cM--Xg--?2cM--Xk--OA. The boy
showed sulfatase-deficient ichthyosis and was Xg(a-), although the
family findings suggest that he should be Xg(a+), but he did not have
chronic granulomatous disease or ocular albinism. On the other hand,
Ropers et al. (1982) suggested the order Xg--H-Y repressor--STS--Xk.
That the Xg locus is near one end of the X chromosome was suggested by
the fact that it shows lack of linkage with so many loci. (The genetic
length of the X chromosome is about 200 cM.) Race and Sanger (1975)
pointed out that when the 3-generation linkage data for deutan (303800),
protan (303900), G6PD (305900) and classic hemophilia (306700) (on the
one hand) versus Xg (on the other) are pooled, the score is 236
nonrecombinants and 193 recombinants: a recombination fraction of 45%
(chi square 4.3, expecting 50% recombination).
Positive evidence that Xg is in the Xp2 region comes mainly from 2
sources. In the first place, Evans et al. (1979) reported morphologic
studies suggesting that about 70% of nonmosaic cases of XX males have
arisen by Xp-Yp interchange in paternal meiosis. In such cases, the
short arm of one X is longer, by 0.4% to 22.9%, than the short arm of
the other X chromosome, and its banding profile is altered. Evans et al.
(1979) found a Y-specific fragment in the DNA digest from 1 of 3 XX
males with Xp+ whom they studied. Combined with this morphologic and
biochemical evidence for Xp-Yp interchange are the data on Xg blood
group in XX males and their parents. In 9 of 12 cases the XX male failed
to inherit the Xg+ gene from his father, suggesting that the Xg locus
was lost in the process of Xp-Yp interchange. These cases were not
studied morphologically; thus the cases without anomaly of Xg
inheritance may have had a cause other than interchange, e.g., occult
mosaicism, transfer of Y material to an autosome, or perhaps an
autosomal recessive gene for sex reversal. (De la Chapelle et al. (1979)
could not corroborate heteromorphism of the X chromosomes in 46,XX
males.) During meiosis the X and Y chromosomes show terminal association
of their short arms, including an electron microscopically demonstrable
synaptinemal complex. This may predispose to X-Y interchange. There
should be XY individuals who are Xg-positive, even though the mother is
Xg-negative, as a result of transfer of their father's Xg+ gene to the Y
chromosome that he gave that particular offspring. Such persons might or
might not have an abnormality of sexual development.
A second web of evidence that Xg is on Xp2 comprises (a) the linkage of
Xg to X-linked ichthyosis (308100), (b) the demonstration of steroid
sulfatase deficiency as the fundamental defect in X-linked ichthyosis,
and (c) the assignment of the steroid sulfatase locus to Xp22-Xpter by
study of deleted X chromosomes in mouse-man somatic cell hybrids
(Mohandas et al., 1980). Both the Xg locus (Race and Sanger, 1975) and
the steroid sulfatase locus (Mohandas et al., 1980) do not, it seems,
participate in lyonization. Thus, the distal part of the short arm of
the X chromosome appears to have 2 properties different from the rest of
the X: pairing with the Y and absence of inactivation. Boyd et al.
(1981) studied an instructive family in which the Xg(a-) mother had a
46Xt(X;Y)(p24;q11) karyotype and had transmitted her X-Y translocation
chromosome to both her son and her daughter. The mother and daughter
were monosomic for the region Xq24-Xqter and the son nullisomic for the
same region. The maternal grandfather was Xg(a+) and neither grandparent
carried the translocation chromosome. Thus, in origin of the
translocation, the Xg locus was lost. The son showed generalized
ichthyosis and zero steroid sulfatase activity. His mother had activity
like that of normal males. Thus, the STS locus must have been involved
also in the deletion of Xp. Ferguson-Smith et al. (1964) had predicted,
on the basis of karyotype-phenotype correlations, that a region of Xp
must escape inactivation and contain the Xg locus. Ropers et al. (1983)
estimated the genetic length of the short arm of the X chromosome to be
about 75-90 cM (the Xg-centromere segment). Sarfarazi et al. (1983)
found no linkage between Xg and a proximal Xp DNA polymorphic marker
called L1.28 (DXS7) and no close linkage between Xg and a more distal
RFLP (lambda-RC8, or DXS9). Curry et al. (1984) found that the steroid
sulfatase, Xg, and MIC2X loci as well as the locus for X-linked
chondrodysplasia punctata (302950) were apparently absent in males with
deletion of Xp22.32.
*FIELD* SA
Boyd et al. (1981); Cook et al. (1963); Ellis et al. (1994); Goodfellow
and Tippett (1981); Marsh (1978); Nakajima et al. (1979); Sanger
et al. (1977); Siniscalco et al. (1966)
*FIELD* RF
1. Bernstein, R.; Wagner, J.; Jenkins, T.; Nurse, G. T.: X-Y translocation
in a mentally retarded XXY male child: possible localization of the
Xg locus. (Abstract) Vth Int. Conf. on Birth Defects, Montreal ,
8/1977.
2. Boyd, E.; Ferguson-Smith, M. A.; Ferguson-Smith, M. E.; Jamieson,
M. E.; Russell, J. E.; Aitken, D. A.; Sanger, R.; Tippett, P.: A
case of X;Y translocation which maps the Xg locus to Xp24-pter. (Abstract) J.
Med. Genet. 18: 224 only, 1981.
3. Boyd, E.; Ferguson-Smith, M. A.; Sanger, R.; Tippett, P.; Aitken,
D. A.: A familial X-Y translocation which assigns the Xg blood group
locus to the region Xp24-pter. (Abstract) Sixth Int. Cong. Hum. Genet.,
Jerusalem 150 only, 1981.
4. Cook, I. A.; Polley, M. J.; Mollison, P. L.: A second example
of anti-Xg(a). Lancet 281: 857-859, 1963. Note: Originally Volume
I.
5. Curry, C. J. R.; Magenis, R. E.; Brown, M.; Lanman, J. T., Jr.;
Tsai, J.; O'Lague, P.; Goodfellow, P.; Mohandas, T.; Bergner, E. A.;
Shapiro, L. J.: Inherited chondrodysplasia punctata due to a deletion
of the terminal short arm of an X chromosome. New Eng. J. Med. 311:
1010-1015, 1984.
6. de la Chapelle, A.; Simola, K.; Simola, P.; Knuutila, S.; Gahmberg,
N.; Pajunen, L.; Lundqvist, C.; Sarna, S.; Murros, J.: Heteromorphic
X chromosomes in 46,XX males? Hum. Genet. 52: 157-167, 1979.
7. Ducos, J.; Morty, Y.; Sanger, R.; Race, R. R.: Xg and X chromosome
inactivation. Lancet 298: 219-220, 1971. Note: Originally Volume
II.
8. Ellis, N. A.; Tippett, P.; Petty, A.; Reid, M.; German, J.; Goodfellow,
P. N.; Thomas, S.; Banting, G.: Identification of the XG blood group
gene. (Abstract) Am. J. Hum. Genet. 55 (suppl.): A14 only, 1994.
9. Ellis, N. A.; Tippett, P.; Petty, A.; Reid, M.; Weller, P. A.;
Ye, T. Z.; German, J.; Goodfellow, P. N.; Thomas, S.; Banting, G.
: PBDX is the XG blood group gene. Nature Genet. 8: 285-290, 1994.
10. Evans, H. J.; Buckton, K. E.; Spowart, G.; Carothers, A. D.:
Heteromorphic X chromosomes in 46,XX males: evidence for the involvement
of X-Y interchange. Hum. Genet. 49: 11-31, 1979.
11. Ferguson-Smith, M. A.; Aitken, D. A.: The contribution of chromosome
aberrations to the precision of human gene mapping. Cytogenet. Cell
Genet. 32: 24-42, 1982.
12. Ferguson-Smith, M. A.; Alexander, D. S.; Bowen, P.; Goodman, R.
M.; Kaufman, B. N.; Jones, H. W., Jr.; Heller, R. H.: Clinical and
cytogenetical studies in female gonadal dysgenesis and their bearing
on the cause of Turner's syndrome. Cytogenetics 3: 355-383, 1964.
13. Goodfellow, P. N.; Tippett, P.: A human quantitative polymorphism
related to Xg blood groups. Nature 289: 404-405, 1981.
14. Johnson, N. C.: XG: the forgotten blood group system. Immunohematology 27:
68-71, 2011.
15. Lawler, S. D.; Sanger, R.: Xg blood-groups and clonal-origin
theory of chronic myeloid leukaemia. Lancet 295: 584-585, 1970.
Note: Originally Volume I.
16. Lee, G. R.; MacDiarmid, W. D.; Cartwright, G. E.; Wintrobe, M.
M.: Hereditary, X-linked, sideroachrestic anemia: the isolation of
two erythrocyte populations differing in XgA blood type and porphyrin
content. Blood 32: 59-70, 1968.
17. Mann, J. D.; Cahan, A.; Gelb, A. G.; Fisher, N.; Hamper, J.; Tippett,
P.; Sanger, R.; Race, R. R.: A sex-linked blood group. Lancet 279:
8-10, 1962. Note: Originally Volume I.
18. Marsh, W. L.: Linkage of the Xg and Xk loci. Cytogenet. Cell
Genet. 22: 531-533, 1978.
19. Mohandas, T.; Shapiro, L. J.; Sparkes, R. S.; Sparkes, M. C.:
Regional assignment of the steroid sulfatase-X-linked ichthyosis locus:
implications for a non-inactivated region on the short arm of the
human X-chromosome. Proc. Nat. Acad. Sci. 76: 5779-5783, 1980.
20. Nakajima, H.; Murato, S.; Seno, T.: Three additional examples
of anti-Xg(a) and Xg blood groups among the Japanese. Transfusion 19:
480-481, 1979.
21. Pearson, P. L.: Personal Communication. Leiden, The Netherlands
1973.
22. Race, R. R.; Sanger, R.: Blood Groups in Man. Oxford: Blackwell
(pub.) (6th ed.): 1975.
23. Ropers, H.-H.; Wieacker, P.; Wienker, T. F.; Davies, K.; Williamson,
R.: On the genetic length of the short arm of the human X chromosome. Hum.
Genet. 65: 53-55, 1983.
24. Ropers, H. H.; Muller, C. R.; Fraccaro, M.: Steroid sulfatase:
gene dosage studies in X chromosome aberrations and XX males. (Abstract) Cytogenet.
Cell Genet. 32: 311 only, 1982.
25. Roychoudhury, A. K.; Nei, M.: Human Polymorphic Genes: World
Distribution. New York: Oxford Univ. Press (pub.) 1988.
26. Sanger, R.; Race, R. R.; Tippett, P.; Hamper, J.; Gavin, J.; Cleghorn,
T. E.: The X-linked blood group system Xg: more tests on unrelated
people and on families. Vox Sang. 7: 571-578, 1962.
27. Sanger, R.; Tippett, P.; Gavin, J.; Teesdale, P.; Daniels, G.
L.: Xg groups and sex chromosome abnormalities in people of Northern
European ancestry: an addendum. J. Med. Genet. 14: 210-211, 1977.
28. Sarfarazi, M.; Harper, P. S.; Kingston, H. M.; Murray, J. M.;
O'Brien, T.; Davies, K. E.; Williamson, R.; Tippett, P.; Sanger, R.
: Genetic linkage relationships between the Xg blood group system
and two X chromosome DNA polymorphisms in families with Duchenne and
Becker muscular dystrophy. Hum. Genet. 65: 169-171, 1983.
29. Siniscalco, M.; Filippi, G.; Latte, B.; Piomelli, S.; Rattazzi,
M.; Gavin, J.; Sanger, R.; Race, R. R.: Failure to detect linkage
between Xg and X-borne loci in Sardinians. Ann. Hum. Genet. 29:
231-252, 1966.
*FIELD* CN
Matthew B. Gross - updated: 9/11/2012
Victor A. McKusick - edited: 3/10/1997
*FIELD* CD
Victor A. McKusick: 6/4/1986
*FIELD* ED
mgross: 09/11/2012
mgross: 9/11/2012
alopez: 3/2/2012
carol: 9/14/2010
terry: 3/31/2009
carol: 11/4/2008
carol: 10/31/2008
terry: 8/26/2008
carol: 4/29/2004
carol: 3/18/2004
terry: 3/13/2001
mark: 3/10/1997
mark: 6/12/1995
terry: 12/5/1994
davew: 8/22/1994
warfield: 4/20/1994
mimadm: 4/18/1994
carol: 11/24/1993