SF3B5

Chr 6

splicing factor 3b subunit 5

Also known as: SF3b10, Ysf3

NCBI Gene: 83443 ENSG00000169976 UniProt: Q9BWJ5

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.

ResearchSummary from RefSeq, UniProt

Enables RNA binding activity and splicing factor binding activity. Involved in mRNA splicing, via spliceosome. Located in nucleoplasm. Part of U12-type spliceosomal complex and U2-type precatalytic spliceosome. [provided by Alliance of Genome Resources, Jul 2025]

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)

—

P/LP submissions

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P/LP missense

1.07

LOEUF

Mechanism· predicted

Some data sources returned errors (1)

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