RRM2B

Chr 8

ribonucleotide reductase regulatory TP53 inducible subunit M2B

Also known as: MTDPS8A, MTDPS8B, P53R2, RCDFRD

NCBI Gene: 50484ENSG00000048392UniProt: Q7LG56

This gene encodes the small subunit of a p53-inducible ribonucleotide reductase. This heterotetrameric enzyme catalyzes the conversion of ribonucleoside diphosphates to deoxyribonucleoside diphosphates. The product of this reaction is necessary for DNA synthesis. Mutations in this gene have been associated with autosomal recessive mitochondrial DNA depletion syndrome, autosomal dominant progressive external ophthalmoplegia-5, and mitochondrial neurogastrointestinal encephalopathy. Alternatively spliced transcript variants have been described.[provided by RefSeq, Feb 2010]

GeneReviewsResearchGenerating clinical summary…

Primary Disease Associations & Inheritance

UniProtMitochondrial DNA depletion syndrome 8A
UniProtMitochondrial DNA depletion syndrome 8B
UniProtProgressive external ophthalmoplegia with mitochondrial DNA deletions, autosomal dominant, 5
UniProtRod-cone dystrophy, sensorineural deafness, and Fanconi-type renal dysfunction

Clinical highlights

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.
1
Active trials
—
Pubs (1 yr)
—
P/LP submissions
—
P/LP missense
0.70
LOEUF
LOF
Mechanism· G2P
📖
GeneReview available — RRM2B
Authoritative clinical overview · Recommended first read
Open GeneReview ↗
Some data sources returned errors (1)

omim: Error: OMIM fetch failed: 429

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

gnomAD
Tolerant — LoF & missense variants common in population
LoF Constraint?
0.70LOEUF
pLI 0.002
Z-score 2.58
OE 0.39 (0.23–0.70)
Tolerant

Typical tolerance to LoF variation

Missense Constraint?
1.21Z-score
OE missense 0.75 (0.65–0.86)
137 obs / 182.9 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios?
LoF OE?0.39 (0.23–0.70)
0≤0.351.4
Missense OE?0.75 (0.65–0.86)
0≤0.61.4
Synonymous OE?0.86
0≤1.21.6
LoF obs/exp: 8 / 20.7Missense obs/exp: 137 / 182.9Syn Z: 0.84

ClinVar Variant Classifications

0 submitted variants in ClinVar

ClinVar

Protein Context — Lollipop Plot

RRM2B · protein map & ClinVar variants

Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.

External Resources

Links to major genomics databases and tools

Franklin by Genoox
AI-powered variant curation and clinical analysis
DECIPHER
Genomic variants and phenotypes in rare disease patients