MRM3
Chr 17mitochondrial rRNA methyltransferase 3
Also known as: RMTL1, RNMTL1
This gene encodes a methyltransferase that modifies mitochondrial 16S ribosomal RNA at position 1370, which is essential for proper assembly and function of the large subunit of mitochondrial ribosomes. Mutations cause Combined Oxidative Phosphorylation Deficiency 7, an autosomal recessive mitochondrial disorder presenting in infancy with severe developmental delay, hypotonia, and lactic acidosis. The gene shows very low constraint against loss-of-function variants (pLI near zero), consistent with autosomal recessive inheritance where heterozygous carriers are typically unaffected.
Population Genetics & Constraint
gnomAD v4 — loss-of-function & missense intolerance
Highly tolerant — LoF variants common in population
Tolerant to missense variation
The highest-scoring mechanism for this gene is dominant-negative.
Note: In-silico variant effect predictors (SIFT, PolyPhen, REVEL, CADD) may underestimate pathogenicity of missense variants in genes with GOF or DN mechanisms. Consider functional evidence and clinical context.
Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312.
ClinVar Variant Classifications
125 submitted variants in ClinVar
Classification Summary
Curated Variants Distribution
Classified variants from ClinVar · 5 ACMG categories· variant type breakdown unavailable
| Classification | LoF | Missense + Inframe | Non-coding | Synonymous | Total |
|---|---|---|---|---|---|
Pathogenic | — | — | — | — | 54 |
Likely Pathogenic | — | — | — | — | 6 |
VUS | — | — | — | — | 56 |
Likely Benign | — | — | — | — | 1 |
Benign | — | — | — | — | 0 |
| Total | — | 117 | |||
Counts from ClinVar esearch · Updated hourly
View in ClinVar →Protein Context — Lollipop Plot
MRM3 · protein map & ClinVar variants
Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.
3D Protein StructureAlphaFold
External Resources
Links to major genomics databases and tools
Clinical Trials
Active and recruiting trials from ClinicalTrials.gov
No active trials found for this gene.
Search ClinicalTrials.gov →External Resources
Links to major genomics databases and tools