CWC27

Chr 5AR

CWC27 spliceosome associated cyclophilin

Also known as: NY-CO-10, RPSKA, SDCCAG-10, SDCCAG10

NCBI Gene: 10283 ENSG00000153015 UniProt: Q6UX04 OMIM: 617170

This protein functions as a component of both major and minor spliceosomes involved in pre-mRNA splicing, despite lacking active peptidyl-prolyl cis-trans isomerase activity. Biallelic mutations cause autosomal recessive retinitis pigmentosa with or without skeletal anomalies. The gene shows low constraint against loss-of-function variants, consistent with the recessive inheritance pattern observed clinically.

OMIM ResearchSummary from RefSeq, OMIM, UniProt

Predicted to enable peptidyl-prolyl cis-trans isomerase activity. Predicted to be involved in mRNA splicing, via spliceosome. Located in nucleoplasm. Part of U2-type precatalytic spliceosome and catalytic step 2 spliceosome. [provided by Alliance of Genome Resources, Jun 2026]

OMIM ResearchGenerating clinical summary…

Primary Disease Associations & Inheritance

Retinitis pigmentosa with or without skeletal anomaliesMIM #250410

Clinical highlights

Gene–disease validity (ClinGen)

Definitive · metaphyseal chondrodysplasia-retinitis pigmentosa syndrome · AR · ClinGen 2025

Interpreting a novel variant

Loss of function is the curated mechanism (Gene2Phenotype), though the gene is not strongly LoF-constrained in the population — weigh truncating variants against that tolerance.Curated gene-level mechanism — a prior for triage, not a per-variant call.

Active trials

Pubs (1 yr)

—

P/LP submissions

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P/LP missense

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LOEUF

LOF

Mechanism· G2P

Some data sources returned errors (1)

gnomad: Error: gnomAD API error: 400

Population Genetics & Constraint

gnomAD

Constraint data not available from gnomAD.

Background carrier burden — how many people carry a rare variant somewhere in CWC27?

gnomAD v4 · ~731k individuals · PASS only

Rare means allele frequency under

Rare missense

1 in 68

660 rare PASS variants

Rare truncating (LoF)

1 in 430

154 rare PASS variants

Rare synonymous (reference)

1 in 190

245 rare PASS variants

Truncating variants are far rarer here than missense — that gap, in human units, is what constraint means for CWC27. A background rate for each class, not the frequency of any particular variant; thin-coverage exons undercount.

By genetic ancestry · 9 gnomAD groups · rare = under 0.1% in that group

Group	People	Missense	Truncating
European (non-Finnish)	~556k	1 in 83	1 in 360
South Asian	~43k	1 in 57	1 in 550
Remaining (unassigned)	~30k	1 in 77	1 in 330
European (Finnish)	~27k	1 in 520	1 in 620
Admixed American	~22k	1 in 65	1 in 290
African / African American	~21k	1 in 66	1 in 380
East Asian	~20k	1 in 110	1 in 310
Ashkenazi Jewish	~13k	1 in 290	1 in 470
Middle Eastern	~2,883	1 in 110	≈ 1 in 1,400

Each group is summed over the variants that are rare in that group. Grey ≈ figures rest on fewer than five expected carriers — too few to distinguish groups. Differences mostly reflect how many people were sampled and how much variation each ancestry carries, not disease risk.