Previous symbols: SARA2.
SAR1B (secretion associated Ras related GTPase 1B) is named by 1 disorder entry: Chylomicron Retention Disease.
SAR1B is the small GTPase that starts COPII coat assembly at endoplasmic reticulum exit sites, and it is specifically required for ER export of apolipoprotein B-containing lipoproteins. The ai-gene-review review of SAR1B was written after the snapshot that feeds this page, so the ingest layer does not yet list any core function terms for it (0).
Chylomicron Retention Disease types SAR1B as causative, with a germline variant origin. The gene sits on the molecular node SAR1B Loss of Function, where its GTPase activity is recorded as decreased. The pathograph runs from that node through defective COPII coat assembly and failed export of pre-chylomicron transport vesicles to chylomicron retention in enterocytes.
ClinGen has classified SAR1B for 0 diseases, so the causative typing rests on the entry's own literature evidence.
Underlined values are claims re-computed from the knowledge base each time this page is built. The tables below are the source of truth.
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 |
|---|---|---|
| Chylomicron Retention Disease | causative germline |
mechanism: SAR1B Loss of Function
animal model: Sar1b CRISPR deletion and p.D137N knock-in mouse; Sar1b knockdown in developing mouse neocortex; Sar1b morpholino knockdown zebrafish
diagnosis: SAR1B molecular genetic testing
|
Identity from HGNC (snapshot 2026-10-01). Page layers are described in the gene pages documentation.