GP1BB
glycoprotein Ib platelet subunit beta
Summary
Platelet glycoprotein Ib (GPIb) is a heterodimeric transmembrane protein consisting of a disulfide-linked 140 kD alpha chain and 22 kD beta chain. It is part of the GPIb-V-IX system that constitutes the receptor for von Willebrand factor (VWF), and mediates platelet adhesion in the arterial circulation. GPIb alpha chain provides the VWF binding site, and GPIb beta contributes to surface expression of the receptor and participates in transmembrane signaling through phosphorylation of its intracellular domain. Mutations in the GPIb beta subunit have been associated with Bernard-Soulier syndrome, velocardiofacial syndrome and giant platelet disorder. The 206 amino acid precursor of GPIb beta is synthesized from a 1.0 kb mRNA expressed in plateletes and megakaryocytes. A 411 amino acid protein arising from a longer, unspliced transcript in endothelial cells has been described; however, the authenticity of this product has been questioned. Yet another less abundant GPIb beta mRNA species of 3.5 kb, expressed in nonhematopoietic tissues such as endothelium, brain and heart, was shown to result from inefficient usage of a non-consensus polyA signal in the neighboring upstream gene (SEPT5, septin 5). In the absence of polyadenylation from its own imperfect site, the SEPT5 gene produces read-through transcripts that use the consensus polyA signal of this gene. [provided by RefSeq, Dec 2010]
Known Variants75 total
| rsid | Position (GRCh37) | Alleles | Class | ClinVar |
|---|---|---|---|---|
| rs730882059 | 22:19,710,933 | C/G | — | pathogenic |
| rs774439004 | 22:19,711,079 | G/A | — | likely benign |
| rs1389191920 | 22:19,711,093 | A/G | — | pathogenic |
| rs1402823262 | 22:19,711,094 | T/C | — | likely pathogenic |
| rs1601247763 | 22:19,711,095 | G/C | — | likely pathogenic |
| rs527896903 | 22:19,711,390 | G/T | — | likely benign |
| rs1601248210 | 22:19,711,413 | T/C | — | likely pathogenic |
| rs2145795850 | 22:19,711,446 | C/T | — | likely pathogenic |
| rs2517804562 | 22:19,711,460 | T/C | — | uncertain significance |
| rs574497337 | 22:19,711,468 | G/A | — | likely benign |
| rs1601248319 | 22:19,711,472 | C/T | — | uncertain significance |
| rs77761572 | 22:19,711,478 | G/C | — | uncertain significance |
| rs375285857 | 22:19,711,485 | G/A | — | benign |
| rs551140561 | 22:19,711,493 | G/T | — | uncertain significance |
| rs121909752 | 22:19,711,503 | G/A | stop gained | pathogenic |
| rs771165985 | 22:19,711,506 | C/T | — | uncertain significance |
| rs536874549 | 22:19,711,509 | C/A | — | pathogenic |
| rs762805097 | 22:19,711,510 | G/T | — | likely benign |
| rs768534974 | 22:19,711,514 | C/A | — | uncertain significance |
| rs2517804734 | 22:19,711,536 | C/T | — | uncertain significance |
| rs749912012 | 22:19,711,543 | G/A | — | likely benign |
| rs2145796039 | 22:19,711,545 | T/C | — | likely pathogenic |
| rs1601248530 | 22:19,711,569 | C/T | — | likely pathogenic |
| rs1424014771 | 22:19,711,578 | C/T | — | uncertain significance |
| rs755380704 | 22:19,711,581 | C/T | — | uncertain significance |
| rs2145796108 | 22:19,711,608 | T/G | — | uncertain significance |
| rs1343054397 | 22:19,711,615 | C/G | — | likely benign |
| rs1197982563 | 22:19,711,634 | C/T | — | likely pathogenic |
| rs2517805000 | 22:19,711,638 | G/A | — | likely pathogenic |
| rs2517805015 | 22:19,711,644 | G/A | — | likely pathogenic |
| rs2145796172 | 22:19,711,647 | A/G | — | likely pathogenic |
| rs1013880318 | 22:19,711,662 | C/T | — | uncertain significance |
| rs566833759 | 22:19,711,672 | C/T | — | likely benign |
| rs1464643023 | 22:19,711,673 | T/C | — | uncertain significance |
| rs1353502015 | 22:19,711,688 | C/G | — | uncertain significance |
| rs957598398 | 22:19,711,690 | C/G | — | likely benign |
| rs1601248780 | 22:19,711,702 | C/G | — | likely benign |
| rs121909750 | 22:19,711,704 | A/G | missense variant | pathogenic |
| rs587783648 | 22:19,711,706 | C/T | missense variant | pathogenic |
| rs1428123812 | 22:19,711,709 | G/T | — | uncertain significance |
| rs2517805222 | 22:19,711,721 | G/A | — | uncertain significance |
| rs547921381 | 22:19,711,755 | C/T | — | benign |
| rs1601248859 | 22:19,711,761 | T/A | — | likely pathogenic |
| rs121909751 | 22:19,711,763 | G/C | missense variant | pathogenic |
| rs142352780 | 22:19,711,765 | C/T | — | conflicting classifications of pathogenicity |
| rs2145796377 | 22:19,711,766 | G/A | — | uncertain significance |
| rs953345181 | 22:19,711,772 | G/T | — | likely pathogenic |
| rs1601248880 | 22:19,711,773 | A/G | — | uncertain significance |
| rs1277516882 | 22:19,711,775 | C/T | — | likely benign |
| rs1601248889 | 22:19,711,776 | T/C | — | likely pathogenic |
| rs1936119557 | 22:19,711,784 | G/T | — | uncertain significance |
| rs1402804629 | 22:19,711,789 | C/A | — | likely pathogenic |
| rs1601248909 | 22:19,711,795 | C/G | — | likely benign |
| rs544345018 | 22:19,711,799 | C/T | — | uncertain significance |
| rs1051842719 | 22:19,711,800 | C/G | — | uncertain significance |
| rs1936120179 | 22:19,711,802 | C/T | — | uncertain significance |
| rs1375840544 | 22:19,711,809 | G/A | — | pathogenic |
| rs1398239892 | 22:19,711,811 | G/A | — | uncertain significance |
| rs1295165100 | 22:19,711,814 | G/A | — | uncertain significance |
| rs2145796512 | 22:19,711,839 | T/G | — | likely pathogenic |
| rs779021847 | 22:19,711,842 | G/T | — | conflicting classifications of pathogenicity |
| rs2517805604 | 22:19,711,857 | A/T | — | uncertain significance |
| rs2517805627 | 22:19,711,862 | T/A | — | uncertain significance |
| rs2145796556 | 22:19,711,866 | T/C | — | pathogenic |
| rs750315624 | 22:19,711,881 | T/C | — | uncertain significance |
| rs2145796628 | 22:19,711,899 | T/G | — | uncertain significance |
| rs542853528 | 22:19,711,910 | G/A | — | uncertain significance |
| rs1257392644 | 22:19,711,911 | C/T | — | uncertain significance |
| rs1020846965 | 22:19,711,917 | C/A | — | uncertain significance |
| rs1438191773 | 22:19,711,939 | G/A | — | likely benign |
| rs1378362532 | 22:19,711,942 | G/A | — | likely benign |
| rs1936125083 | 22:19,711,950 | C/G | — | uncertain significance |
| rs544996817 | 22:19,711,998 | G/C | — | uncertain significance |
| rs79998786 | 22:19,712,064 | G/C | — | uncertain significance |
| rs1059196 | 22:19,712,094 | C/T | — | benign |
Gene information from NCBI Gene. Variant classifications from ClinVar.