B4GALT5

Chr 20

beta-1,4-galactosyltransferase 5

Also known as: B4Gal-T5, BETA4-GALT-IV, beta4Gal-T5, beta4GalT-V, gt-V

NCBI Gene: 9334 ENSG00000158470 UniProt: O43286 OMIM: 604016

The B4GALT5 protein catalyzes the synthesis of lactosylceramide, which is the starting point for ganglioside biosynthesis essential for neuronal maturation, axonal development, and myelin formation. Mutations cause a rare autosomal recessive disorder characterized by severe developmental delays, intellectual disability, and neurological abnormalities. This gene is highly constrained against loss-of-function variants in the population, reflecting its critical role in nervous system development.

OMIM ResearchSummary from RefSeq, UniProt

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. The function of the enzyme encoded by this gene is not clear. This gene was previously designated as B4GALT4 but was renamed to B4GALT5. In the literature it is also referred to as beta4GalT2. [provided by RefSeq, Jul 2008]

OMIM ResearchGenerating clinical summary…

Clinical highlights

Interpreting a novel variant

This gene is strongly intolerant of loss-of-function variation in the population, so LoF variants warrant close attention. No curated mechanism annotation is available — see the mechanism card for the computational prediction and its caveats.Based on population constraint only.

Active trials

Pubs (1 yr)

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P/LP submissions

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P/LP missense

0.15

LOEUF· LoF intol.

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Mechanism