Previous symbols: ITM1. Aliases: TMC, MGC9042, STT3-A.
STT3A (STT3 oligosaccharyltransferase complex catalytic subunit A) is named by 1 disorder entry.
ai-gene-review gives STT3A's core molecular function as dolichyl-diphosphooligosaccharide-protein glycotransferase activity, the catalytic subunit of the OST-A complex that transfers the preassembled glycan onto nascent polypeptides, acting in protein N-linked glycosylation; and protein co-translational transfer of dolichol-linked oligosaccharide at the endoplasmic reticulum membrane.
The one entry naming STT3A types it as causative, STT3A-Congenital Disorder of Glycosylation, with germline variants (STT3A-Congenital Disorder of Glycosylation). The entry covers a recessive and a dominant form, and records the functional impact as dominant negative and loss of function. ClinGen rates STT3A for 2 diseases, and the entry's tiers are moderate and definitive (recessive and dominant forms respectively). STT3A sits on 3 nodes, including Reduced OST-A Oligosaccharyltransferase Activity.
The nodes naming STT3A carry 0 process terms, so the KB and ai-gene-review share 0 GO process terms on them; the co-translational N-glycosylation defect is recorded on the downstream node.
Underlined values are claims re-computed from the knowledge base each time this page is built. The tables below are the source of truth.
ai-gene-review has this gene at status INITIALIZED; the description is shown only once the review is complete. Read the draft upstream.
Relationship is the entry's genetic[].relationship_type. untyped means the entry has a genetic record for the gene but does not type it; its free-text association is shown instead.
| Disorder | Relationship | Where the gene appears |
|---|---|---|
| STT3A-Congenital Disorder of Glycosylation |
causative
germline
dominant negativeloss of function
CLINGEN: moderate (AR-STT3A-CDG) CLINGEN: definitive (AD-STT3A-CDG)
|
mechanism: Biallelic STT3A Loss-of-Function Variants; Heterozygous STT3A Catalytic-Site Missense Variants; Reduced OST-A Oligosaccharyltransferase Activity
subtype: AD-STT3A-CDG; AR-STT3A-CDG
animal model: Heterozygous stt3a knockdown zebrafish
|
An entry matches when ClinGen's MONDO disease is the entry's own disease term, a subtype term, or an exact-match mapping. An amber status marks an entry ClinGen supports the gene for (Definitive, Strong or Moderate) whose own record does not type it. A Limited, Disputed or Refuted tier on such an entry is not a gap.
| ClinGen disease | MOI | Classification | dismech entry |
|---|---|---|---|
| STT3A-congenital disorder of glycosylation MONDO:0014270 | AR | Moderate 2025-04-16 |
|
| congenital disorder of glycosylation, type Iw, autosomal dominant MONDO:0859223 | AD | Definitive 2025-06-05 |
Identity from HGNC (snapshot 2026-10-01). Page layers are described in the gene pages documentation.