RNU12

Chr 22AR

RNA, U12 small nuclear

Also known as: CDAGS, RNU12-1, RNU12L, RNU12P, SCAR33, dJ222E13.7

NCBI Gene: 267010 ENSG00000276027 OMIM: 620204

RNU12 encodes the U12 small nuclear RNA component of the U12 snRNP complex, which is essential for splicing of U12-type introns in pre-mRNA processing. Mutations cause autosomal recessive spinocerebellar ataxia 33 and CDAGS syndrome (craniosynostosis, delayed closure of fontanelles, cranial defects, clavicular hypoplasia, anal defects, and skin eruption). Both conditions follow autosomal recessive inheritance and involve neurological dysfunction along with additional developmental abnormalities in CDAGS syndrome.

OMIM ResearchSummary from RefSeq, OMIM

Predicted to enable pre-mRNA branch point binding activity. Predicted to be involved in negative regulation of neuron apoptotic process. Predicted to act upstream of or within RNA splicing. Predicted to be part of U12 snRNP. Implicated in autosomal recessive spinocerebellar ataxia 33. [provided by Alliance of Genome Resources, Jul 2025]

OMIM ResearchGenerating clinical summary…

Primary Disease Associations & Inheritance

?Spinocerebellar ataxia, autosomal recessive 33MIM #620208

CDAGS syndromeMIM #603116

Clinical highlights

Gene–disease validity (ClinGen)

Moderate · RNU12-related minor spliceopathy disorder · AR · ClinGen 2026

Active trials

Pubs (1 yr)

—

P/LP submissions

—

P/LP missense

—

LOEUF

—

Mechanism

Population Genetics & Constraint

gnomAD

Constraint data not available from gnomAD.

Background carrier burden — how many people carry a rare variant somewhere in RNU12?

gnomAD v4 · ~0k individuals · PASS only

Rare means allele frequency under

Rare missense

none observed

0 rare PASS variants

Rare truncating (LoF)

none observed

0 rare PASS variants

Rare synonymous (reference)

none observed

0 rare PASS variants

Rare missense and truncating variants are carried at similar rates in RNU12; this gene does not show strong loss-of-function constraint by this measure. A background rate for each class, not the frequency of any particular variant; thin-coverage exons undercount.