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…

AR2 OMIM phenotypes

Clinical Summary— RNU12

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Gene-Disease Validity (ClinGen)

RNU12-related minor spliceopathy disorder · ARModerate

Moderate evidence — consider for supplementary testing

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ClinVar Variants

7 unique Pathogenic / Likely Pathogenic· 4 VUS of 15 total submissions

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Population Genetics & Constraint

gnomAD

Constraint data not available from gnomAD.

ClinVar Variant Classifications

15 submitted variants in ClinVar

ClinVar

Classification Summary

Pathogenic5

Likely Pathogenic2

VUS4

Likely Benign1

Benign1

Conflicting2

Pathogenic

Likely Pathogenic

VUS

Likely Benign

Benign

Conflicting

Curated Variants Distribution

Classified variants from ClinVar · 5 ACMG categories

Classification	LoF	Missense + Inframe	Non-coding	Synonymous	Total
Pathogenic	0	0	5	0	5
Likely Pathogenic	0	0	2	0	2
VUS	0	0	4	0	4
Likely Benign	0	0	1	0	1
Benign	0	0	1	0	1
Conflicting	—				2
Total	0	0	13	0	15

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

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11 pathogenic / likely-pathogenic (of 11) ClinVar copy-number / structural variants overlap RNU12 — these span large chromosomal regions, not the gene specifically, and are excluded from the counts above. Explore in CNV tools →