SGSM2

Chr 17

small G protein signaling modulator 2

Also known as: RUTBC1

The encoded protein functions as a GTPase activator that inactivates RAB32, RAB33B, and RAB38, thereby regulating membrane trafficking and the transport of melanogenic enzymes to melanosomes in melanocytes. Mutations cause autosomal recessive oculocutaneous albinism, characterized by reduced pigmentation affecting the eyes and skin. This gene shows low constraint to loss-of-function variation.

OMIMResearchSummary from RefSeq, UniProt
MultiplemechanismLOEUF 0.60
Clinical SummarySGSM2
Population Constraint (gnomAD)
Low constraint (pLI 0.00) — loss-of-function variants are relatively tolerated in the population.

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Tolerant — LoF & missense variants common in population
LoF Constraint
0.60LOEUF
pLI 0.000
Z-score 3.95
OE 0.43 (0.310.60)
Tolerant

Typical tolerance to LoF variation

Missense Constraint
0.30Z-score
OE missense 0.97 (0.911.03)
649 obs / 670.8 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios
LoF OE0.43 (0.310.60)
00.351.4
Missense OE0.97 (0.911.03)
00.61.4
Synonymous OE1.11
01.21.6
LoF obs/exp: 24 / 55.9Missense obs/exp: 649 / 670.8Syn Z: -1.49
DN
0.6840th %ile
GOF
0.72top 25%
LOF
0.2872th %ile

This gene has evidence for multiple mechanisms of pathogenicity (gain-of-function and dominant-negative). Both the Badonyi & Marsh prediction and the broader genomic evidence point to gain-of-function as the predominant mechanism. Different variants in this gene may act through different mechanisms — interpret in context of the specific variant.

GOFprediction above median
DNprediction above median

Note: In-silico variant effect predictors (SIFT, PolyPhen, REVEL, CADD) may underestimate pathogenicity of missense variants in genes with GOF or DN mechanisms. Consider functional evidence and clinical context.

Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312.

ClinVar Variant Classifications

0 submitted variants in ClinVar

Protein Context — Lollipop Plot

SGSM2 · protein map & ClinVar variants

Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.

3D Protein StructureAlphaFold

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

No active trials found for this gene.

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Clinical Literature
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