CNNM2

Chr 10ADAR

cyclin and CBS domain divalent metal cation transport mediator 2

Also known as: ACDP2, HOMG6, HOMGSMR, SLC70A2

CNNM2 encodes a divalent metal cation transporter that mediates epithelial transport and renal reabsorption of magnesium. Mutations cause hypomagnesemia with either isolated renal involvement or a more severe phenotype with seizures and intellectual disability, inherited in either autosomal dominant or recessive patterns. The gene is highly constrained against loss-of-function variants (pLI 0.995, LOEUF 0.267), indicating intolerance to complete protein loss.

OMIMResearchSummary from RefSeq, OMIM, UniProt
LOFmechanismAD/ARLOEUF 0.272 OMIM phenotypes
Clinical SummaryCNNM2
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Gene-Disease Validity (ClinGen)
hypomagnesemia, seizures, and intellectual disability 1 · SDDefinitive

Definitive — sufficient evidence for diagnostic panels

Population Constraint (gnomAD)
Highly constrained gene — heterozygous loss-of-function variants are very rare in the population (pLI 1.00). One damaged copy is likely sufficient to cause disease.

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Dual constrained — LoF & missense intolerant
LoF Constraint
0.27LOEUF
pLI 0.995
Z-score 4.48
OE 0.10 (0.050.27)
Highly constrained

Highly LoF-intolerant (top ~10% of genes)

Missense Constraint
4.41Z-score
OE missense 0.44 (0.400.49)
219 obs / 495.2 exp
Constrained

Highly missense-constrained (top ~0.1%)

Observed / Expected Ratios
LoF OE0.10 (0.050.27)
00.351.4
Missense OE0.44 (0.400.49)
00.61.4
Synonymous OE1.10
01.21.6
LoF obs/exp: 3 / 29.0Missense obs/exp: 219 / 495.2Syn Z: -1.19
Curated Mechanism (G2P)Gene2Phenotype (DDG2P) ↗
definitiveCNNM2-related neurodevelopmental disorder with hypomagnesemiaLOFAR
strongCNNM2-related neurodevelopmental disorder with hypomagnesemiaOTHERAD
DN
0.4686th %ile
GOF
0.6248th %ile
LOF
0.64top 25%

The highest-scoring mechanism for this gene is loss-of-function (haploinsufficiency).

LOF1 literature citation · LOEUF 0.27

Literature Evidence

LOFThe phenotypic and genetic spectrum of patients with heterozygous mutations in cyclin M2 (CNNM2)PMID:33600043

Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312. Mechanism ranking also informed by gnomAD constraint, ClinVar, and ClinGen data.

ClinVar Variant Classifications

0 submitted variants in ClinVar

Protein Context — Lollipop Plot

CNNM2 · 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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