SF3B5

Chr 6

splicing factor 3b subunit 5

Also known as: SF3b10, Ysf3

The protein functions as a component of the SF3B subcomplex within the U2 snRNP spliceosome, where it mediates recognition of intron branch sites and promotes selection of the branch-site adenosine during pre-mRNA splicing. Biallelic pathogenic variants cause microcephaly with simplified gyral pattern, abnormal corpus callosum, and seizures, inherited in an autosomal recessive manner. Affected individuals typically present in early infancy with developmental delays and neurological abnormalities.

OMIMResearchSummary from RefSeq, UniProt
DNmechanismLOEUF 1.07
Clinical SummarySF3B5
Population Constraint (gnomAD)
Moderately constrained gene (pLI 0.58) — some intolerance to loss-of-function variants.
📋
ClinVar Variants
18 unique Pathogenic / Likely Pathogenic· 6 VUS of 24 total submissions

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Moderate LoF intolerance
LoF Constraint
1.07LOEUF
pLI 0.584
Z-score 1.53
OE 0.00 (0.001.07)
Moderately constrained

Highly tolerant — LoF variants common in population

Missense Constraint
1.19Z-score
OE missense 0.52 (0.380.72)
25 obs / 48.1 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios
LoF OE0.00 (0.001.07)
00.351.4
Missense OE0.52 (0.380.72)
00.61.4
Synonymous OE1.21
01.21.6
LoF obs/exp: 0 / 2.7Missense obs/exp: 25 / 48.1Syn Z: -0.72
DN
0.6260th %ile
GOF
0.6051th %ile
LOF
0.4332th %ile

The highest-scoring mechanism for this gene is dominant-negative.

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

24 submitted variants in ClinVar

Classification Summary

Pathogenic18
VUS6
18
Pathogenic
6
VUS

Curated Variants Distribution

Classified variants from ClinVar · 5 ACMG categories

ClassificationLoFMissense + InframeNon-codingSynonymousTotal
Pathogenic
0
0
18
0
18
Likely Pathogenic
0
0
0
0
0
VUS
0
5
1
0
6
Likely Benign
0
0
0
0
0
Benign
0
0
0
0
0
Total0519024

LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly

View in ClinVar →

Protein Context — Lollipop Plot

SF3B5 · 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.

Search ClinicalTrials.gov →
Clinical Literature
Open Research Assistant →
Key Publications
Landmark & review papers · by relevance
PubMed
Top 1 results · since 2015Search PubMed ↗
Recent Gene-Specific Literature
Gene in title · MEDLINE · newest first
Europe PMC