MTNR1A
Chr 4melatonin receptor 1A
Also known as: MEL-1A-R, MT1
This protein is a high-affinity G-protein coupled receptor for melatonin that mediates circadian rhythm and reproductive functions, primarily localized to the hypothalamic suprachiasmatic nucleus and pituitary. Mutations cause autosomal recessive nonsyndromic intellectual disability and may be associated with sleep disorders given the gene's role in melatonin signaling. The gene shows very low constraint against loss-of-function variants (pLI near zero), consistent with recessive inheritance requiring biallelic mutations for disease manifestation.
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
202 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 | 103 | 0 | 103 |
Likely Pathogenic | 0 | 0 | 12 | 0 | 12 |
VUS | 0 | 38 | 33 | 0 | 71 |
Likely Benign | 0 | 2 | 2 | 2 | 6 |
Benign | 0 | 2 | 3 | 2 | 7 |
Conflicting | — | 1 | |||
| Total | 0 | 42 | 153 | 4 | 200 |
LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly
View in ClinVar →Protein Context — Lollipop Plot
MTNR1A · 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
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