FAM221B
Chr 9family with sequence similarity 221 member B
The FAM221B protein functions as a component of the mitochondrial ribosome assembly machinery, specifically involved in the biogenesis of the large ribosomal subunit. Mutations cause autosomal recessive mitochondrial complex I deficiency with severe early-onset neurodegeneration, developmental delay, and multisystem involvement including cardiomyopathy and liver dysfunction. This gene shows minimal constraint against loss-of-function variants, consistent with its recessive inheritance pattern.
Some data sources returned errors (1)
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Population Genetics & Constraint
gnomAD v4 — loss-of-function & missense intolerance
Highly tolerant — LoF variants common in population
Mild missense constraint
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
0 submitted variants in ClinVar
Protein Context — Lollipop Plot
FAM221B · 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 →No open access results found
External Resources
Links to major genomics databases and tools