B4GALT1

beta-1,4-galactosyltransferase 1

Summary

This gene is one of seven beta-1,4-galactosyltransferase (beta4GalT) genes. They encode type II membrane-bound glycoproteins that appear to have exclusive specificity for the donor substrate UDP-galactose; all transfer galactose in a beta1,4 linkage to similar acceptor sugars: GlcNAc, Glc, and Xyl. Each beta4GalT has a distinct function in the biosynthesis of different glycoconjugates and saccharide structures. As type II membrane proteins, they have an N-terminal hydrophobic signal sequence that directs the protein to the Golgi apparatus and which then remains uncleaved to function as a transmembrane anchor. By sequence similarity, the beta4GalTs form four groups: beta4GalT1 and beta4GalT2, beta4GalT3 and beta4GalT4, beta4GalT5 and beta4GalT6, and beta4GalT7. This gene is unique among the beta4GalT genes because it encodes an enzyme that participates both in glycoconjugate and lactose biosynthesis. For the first activity, the enzyme adds galactose to N-acetylglucosamine residues that are either monosaccharides or the nonreducing ends of glycoprotein carbohydrate chains. The second activity is restricted to lactating mammary tissues where the enzyme forms a heterodimer with alpha-lactalbumin to catalyze UDP-galactose + D-glucose <=> UDP + lactose. The two enzymatic forms result from alternate transcription initiation sites and post-translational processing. Two transcripts, which differ only at the 5' end, with approximate lengths of 4.1 kb and 3.9 kb encode the same protein. The longer transcript encodes the type II membrane-bound, trans-Golgi resident protein involved in glycoconjugate biosynthesis. The shorter transcript encodes a protein which is cleaved to form the soluble lactose synthase. [provided by RefSeq, Jul 2008]

Known Variants132 total

rsidPosition (GRCh37)AllelesClassClinVar
rs8860638599:33,110,734C/Guncertain significance
rs8860638659:33,111,578G/Auncertain significance
rs413036619:33,111,953G/A3 prime UTR variant
rs8860638719:33,112,738C/Guncertain significance
rs1905585559:33,113,166A/C3 prime UTR variant
rs70198969:33,113,196T/Gbenign
rs1408677479:33,113,298T/Clikely benign
rs1498001259:33,113,299G/Alikely benign
rs70199099:33,113,322T/Cbenign
rs24892082949:33,113,455G/Cuncertain significance
rs1416367159:33,113,493A/Gbenign
rs7775365319:33,113,500T/Auncertain significance
rs18398945769:33,113,519T/Cuncertain significance
rs7734257429:33,113,537A/Cuncertain significance
rs3776785669:33,113,553T/Auncertain significance
rs7525238749:33,113,589A/Glikely benign
rs3749196219:33,113,596A/Tlikely benign
rs1144381929:33,113,740G/Clikely benign
rs1823596669:33,113,767T/Aconflicting classifications of pathogenicity
rs5515646839:33,113,781T/Cpathogenic
rs1470704689:33,113,786T/Clikely benign
rs1421502389:33,113,849A/Glikely benign
rs2009431219:33,113,888A/Glikely benign
rs123795019:33,113,970C/Tbenign
rs1148715959:33,115,854C/Tlikely benign
rs1434127899:33,115,967A/Glikely benign
rs14453430079:33,115,974A/Glikely benign
rs7648052919:33,116,050T/Cuncertain significance
rs8860421769:33,116,081G/Cuncertain significance
rs8860421759:33,116,084A/Cuncertain significance
rs7495407409:33,116,121A/Glikely benign
rs11376429:33,118,904A/G
rs64763989:33,119,241C/A
rs101219879:33,119,818A/T
rs19699779:33,120,203A/Gbenign
rs19699769:33,120,204A/Gbenign
rs349196929:33,120,211A/Gbenign
rs360076639:33,120,261T/Cbenign
rs7682029239:33,120,439C/Tuncertain significance
rs7508022969:33,120,442C/Tuncertain significance
rs18400040759:33,120,453C/Tuncertain significance
rs7552518559:33,120,463A/Cuncertain significance
rs7500492139:33,120,476C/Tlikely benign
rs1389223979:33,120,477G/Auncertain significance
rs91699:33,120,483T/Clikely benign
rs21180550809:33,120,488A/Glikely benign
rs2014179129:33,120,496G/Clikely benign
rs7666039259:33,120,537T/Cuncertain significance
rs24892183279:33,120,550C/Tuncertain significance
rs7614638439:33,120,592T/Cuncertain significance
rs38185939:33,120,706A/Gbenign
rs772529939:33,120,765T/Cbenign
rs109714179:33,121,480C/Tintron variant
rs108139489:33,121,570G/C
rs101169669:33,122,370T/Aintron variant
rs101139039:33,122,645G/Cintron variant
rs107581889:33,123,386A/Gintron variant
rs107389059:33,123,627A/Gintron variant
rs123428319:33,124,872T/Cregulatory region variant
rs109714209:33,125,000T/Cregulatory region variant
rs107581899:33,125,804T/Cregulatory region variant
rs78508789:33,126,570A/Gregulatory region variant
rs108139519:33,128,021A/Gintron variant
rs37804909:33,129,839A/Gregulatory region variant
rs1404556999:33,134,000C/Tintron variant
rs625443849:33,134,862A/Tbenign
rs9132149:33,135,085G/Abenign
rs18402483029:33,135,181C/Tuncertain significance
rs1452411289:33,135,214C/Tlikely benign
rs9424984259:33,135,224C/Tuncertain significance
rs10657659:33,135,238G/Abenign
rs18402498559:33,135,256G/Cpathogenic
rs3709733459:33,135,260T/Guncertain significance
rs3746114359:33,135,278T/Cuncertain significance
rs14128359169:33,135,288G/Cuncertain significance
rs2015644069:33,135,297T/Cuncertain significance
rs14119795729:33,135,309G/Auncertain significance
rs1459788649:33,135,318C/Tuncertain significance
rs1469966569:33,135,322G/Cuncertain significance
rs9401410489:33,135,348T/Cconflicting classifications of pathogenicity
rs7560499049:33,135,376G/Alikely benign
rs7536752239:33,135,390C/Tuncertain significance
rs7702696289:33,135,440G/Alikely benign
rs107389069:33,135,634T/Cbenign
rs107389079:33,135,890T/Aregulatory region variant
rs108139549:33,137,596A/T
rs37804869:33,139,453C/A
rs48785259:33,140,789C/A
rs78687819:33,141,320A/T
rs27708089:33,142,412G/Aintron variant
rs1445921789:33,143,043T/Cintron variant
rs38244589:33,144,809C/Tintron variant
rs5633455209:33,145,623G/A
rs107389099:33,148,834T/G
rs1131979449:33,149,340G/Aintron variant
rs108139579:33,153,527G/Tintron variant
rs560307779:33,163,059G/Aregulatory region variant
rs37804809:33,163,486G/Tupstream gene variant
rs109714339:33,166,615T/Cbenign
rs7524709869:33,166,741G/Alikely benign

Showing 100 of 132 variants. Use the SNP search for the full list.

Gene information from NCBI Gene. Variant classifications from ClinVar.