TMEM220
Chr 17transmembrane protein 220
TMEM220 encodes a predicted membrane protein with unknown specific function. Biallelic mutations cause autosomal recessive developmental delay, seizures, and progressive neurodegeneration with onset in infancy or early childhood. The gene shows high tolerance to loss-of-function variants in the population, suggesting the pathogenic variants may have specific effects on protein function.
Population Genetics & Constraint
gnomAD v4 — loss-of-function & missense intolerance
Highly tolerant — LoF variants common in population
Mild missense constraint
This gene has evidence for multiple mechanisms of pathogenicity (gain-of-function and dominant-negative). Both the Badonyi & Marsh prediction and the broader genomic evidence point to gain-of-function as the predominant mechanism. Different variants in this gene may act through different mechanisms — interpret in context of the specific variant.
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
50 submitted variants in ClinVar
Classification Summary
Curated Variants Distribution
Classified variants from ClinVar · 5 ACMG categories
| Classification | LoF | Missense + Inframe | Non-coding | Synonymous | Total |
|---|---|---|---|---|---|
Pathogenic | 0 | 0 | 11 | 0 | 11 |
Likely Pathogenic | 0 | 0 | 0 | 0 | 0 |
VUS | 0 | 23 | 7 | 0 | 30 |
Likely Benign | 0 | 2 | 0 | 1 | 3 |
Benign | 0 | 1 | 0 | 0 | 1 |
| Total | 0 | 26 | 18 | 1 | 45 |
LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly
View in ClinVar →Protein Context — Lollipop Plot
TMEM220 · 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