CNNM3

Chr 2

cyclin and CBS domain divalent metal cation transport mediator 3

Also known as: ACDP3, SLC70A3

The CNNM3 protein is a transmembrane metal transporter involved in magnesium ion homeostasis. Mutations cause autosomal recessive hypomagnesemia with seizures and intellectual disability, typically presenting in infancy or early childhood. The gene shows low constraint against loss-of-function variants, consistent with its recessive inheritance pattern.

OMIMResearchSummary from RefSeq, UniProt
MultiplemechanismLOEUF 0.97
Clinical SummaryCNNM3
Population Constraint (gnomAD)
Low constraint (pLI 0.00) — loss-of-function variants are relatively tolerated in the population.

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Tolerant — LoF & missense variants common in population
LoF Constraint
0.97LOEUF
pLI 0.000
Z-score 1.66
OE 0.62 (0.410.97)
Tolerant

Typical tolerance to LoF variation

Missense Constraint
0.76Z-score
OE missense 0.88 (0.790.97)
256 obs / 292.4 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios
LoF OE0.62 (0.410.97)
00.351.4
Missense OE0.88 (0.790.97)
00.61.4
Synonymous OE1.05
01.21.6
LoF obs/exp: 14 / 22.5Missense obs/exp: 256 / 292.4Syn Z: -0.47
DN
0.6646th %ile
GOF
0.79top 10%
LOF
0.3453th %ile

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.

GOFprediction above median
DNprediction above median

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

CNNM3 · protein map & ClinVar variants

Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.

3D Protein StructureAlphaFold

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

No active trials found for this gene.

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Clinical Literature
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