MMP21
Chr 10ARmatrix metallopeptidase 21
Also known as: HTX7, MMP-21
This gene encodes a matrix metalloproteinase that functions as a protease and may regulate potassium channel surface expression by retaining them in the endoplasmic reticulum. Mutations cause visceral heterotaxy-7, a developmental disorder affecting the normal left-right asymmetry of internal organs, inherited in an autosomal recessive pattern. The gene shows minimal constraint against loss-of-function variation.
Population Genetics & Constraint
gnomAD v4 — loss-of-function & missense intolerance
Highly tolerant — LoF variants common in population
Mild missense constraint
Predictions shown for reference only — model trained on dominant genes, not applicable to AR conditions.
The Badonyi & Marsh prediction model was trained exclusively on dominant disease genes. Predictions are not reliable for genes with autosomal recessive inheritance and are shown at reduced opacity for reference only.
Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312.
ClinVar Variant Classifications
148 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 | 4 | 5 | 44 | 0 | 53 |
Likely Pathogenic | 5 | 2 | 0 | 0 | 7 |
VUS | 0 | 74 | 5 | 0 | 79 |
Likely Benign | 0 | 1 | 0 | 3 | 4 |
Benign | 0 | 0 | 0 | 0 | 0 |
| Total | 9 | 82 | 49 | 3 | 143 |
LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly
View in ClinVar →Protein Context — Lollipop Plot
MMP21 · 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