GRAMD1B

Chr 11

GRAM domain containing 1B

Also known as: LAMb, LINC01059

NCBI Gene: 57476 ENSG00000023171 UniProt: Q3KR37 OMIM: 620179

The protein functions as a cholesterol transporter that mediates non-vesicular cholesterol transfer from the plasma membrane to the endoplasmic reticulum at membrane contact sites, playing a crucial role in cellular cholesterol homeostasis. Mutations in this highly constrained gene (pLI=1.0, LOEUF=0.25) cause autosomal recessive congenital adrenal insufficiency with distinctive clinical features. The gene's critical role in adrenal steroidogenesis and its extreme intolerance to loss-of-function variants make it an important consideration in patients presenting with primary adrenal insufficiency.

OMIM ResearchSummary from RefSeq, UniProt

Enables cholesterol transfer activity. Involved in lysosome to ER cholesterol transport. Located in endoplasmic reticulum; endoplasmic reticulum-plasma membrane contact site; and plasma membrane. Is active in endoplasmic reticulum membrane. [provided by Alliance of Genome Resources, Jun 2026]

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

0.24

LOEUF· LoF intol.

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Mechanism