STT3A

Chr 11ADAR

STT3 oligosaccharyltransferase complex catalytic subunit A

Also known as: CDG1WAD, CDG1WAR, ITM1, STT3-A, TMC

NCBI Gene: 3703 ENSG00000134910 UniProt: P46977 OMIM: 601134

The protein is a catalytic subunit of the oligosaccharyl transferase complex that transfers glycan chains to asparagine residues during protein N-glycosylation in the endoplasmic reticulum, a critical step in protein processing. Mutations cause congenital disorder of glycosylation type Iw with both autosomal dominant and autosomal recessive inheritance patterns. The gene is highly constrained against loss-of-function variants (LOEUF 0.488), reflecting its essential role in cellular protein modification.

OMIM ResearchSummary from RefSeq, OMIM, UniProt

The protein encoded by this gene is a catalytic subunit of the N-oligosaccharyltransferase (OST) complex, which functions in the endoplasmic reticulum to transfer glycan chains to asparagine residues of target proteins. A separate complex containing a similar catalytic subunit with an overlapping function also exists. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Aug 2015]

OMIM ResearchGenerating clinical summary…

Primary Disease Associations & Inheritance

Congenital disorder of glycosylation, type Iw, autosomal dominantMIM #619714

Congenital disorder of glycosylation, type Iw, autosomal recessiveMIM #615596

Clinical highlights

Gene-disease validity (ClinGen)

STT3A-congenital disorder of glycosylation · ARModerateconsider for supplementary testing2 gene-disease associations curated in total

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.Curated gene-level mechanism — a prior for triage, not a per-variant call.

Active trials

Pubs (1 yr)

—

P/LP submissions

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P/LP missense

0.49

LOEUF

Mechanism· predicted