SPTSSB

Chr 3

serine palmitoyltransferase small subunit B

Also known as: ADMP, C3orf57, SSSPTB

Serine palmitoyltransferase (SPT; EC 2.3.1.50) catalyzes the first committed and rate-limiting step in sphingolipid biosynthesis. SSSPTB is a small SPT subunit that stimulates SPT activity and confers acyl-CoA preference to the SPT catalytic heterodimer of SPTLC1 (MIM 605712) and either SPTLC2 (MIM 605713) or SPTLC3 (MIM 611120) (Han et al., 2009 [PubMed 19416851]).[supplied by OMIM, Nov 2010]

ResearchGenerating clinical summary…
MultiplemechanismLOEUF 1.91
Clinical SummarySPTSSB
Population Constraint (gnomAD)
Low constraint (pLI 0.00) — loss-of-function variants are relatively tolerated in the population.
Some data sources returned errors (1)

omim: Error: OMIM fetch failed: 429

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Tolerant — LoF & missense variants common in population
LoF Constraint?
1.91LOEUF
pLI 0.001
Z-score -0.47
OE 1.29 (0.581.91)
Tolerant

Highly tolerant — LoF variants common in population

Missense Constraint?
0.12Z-score
OE missense 0.95 (0.741.23)
41 obs / 43.2 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios?
LoF OE?1.29 (0.581.91)
00.351.4
Missense OE?0.95 (0.741.23)
00.61.4
Synonymous OE?1.05
01.21.6
LoF obs/exp: 4 / 3.1Missense obs/exp: 41 / 43.2Syn Z: -0.15

This gene — mechanism propensity

DN
0.75top 25%
GOF
0.78top 25%
LOF
0.2581th %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

SPTSSB · protein map & ClinVar variants

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

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

No active trials found for this gene.

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