CHMP2B

Chr 3AD

charged multivesicular body protein 2B

Also known as: ALS17, CHMP2.5, DMT1, FTDALS7, VPS2-2, VPS2B

The protein is a core component of the ESCRT-III complex that sorts endosomal cargo proteins into multivesicular bodies for lysosomal degradation and functions in membrane fission events including cytokinesis. Mutations cause frontotemporal dementia and/or amyotrophic lateral sclerosis 7, typically presenting in adulthood with progressive cognitive decline and/or motor neuron degeneration. Inheritance is autosomal dominant.

OMIMResearchSummary from RefSeq, OMIM, UniProt
MultiplemechanismADLOEUF 1.221 OMIM phenotype
Clinical SummaryCHMP2B
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Gene-Disease Validity (ClinGen)
frontotemporal dementia and/or amyotrophic lateral sclerosis 7 · ADDefinitive

Definitive — sufficient evidence for diagnostic panels

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
1.22LOEUF
pLI 0.000
Z-score 0.98
OE 0.72 (0.441.22)
Tolerant

Highly tolerant — LoF variants common in population

Missense Constraint
0.34Z-score
OE missense 0.91 (0.781.07)
103 obs / 113.2 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios
LoF OE0.72 (0.441.22)
00.351.4
Missense OE0.91 (0.781.07)
00.61.4
Synonymous OE0.97
01.21.6
LoF obs/exp: 10 / 14.0Missense obs/exp: 103 / 113.2Syn Z: 0.14
DN
0.87top 5%
GOF
0.7030th %ile
LOF
0.2288th %ile

This gene has evidence for multiple mechanisms of pathogenicity (dominant-negative and gain-of-function). Both the Badonyi & Marsh prediction and the broader genomic evidence point to dominant-negative as the predominant mechanism. Different variants in this gene may act through different mechanisms — interpret in context of the specific variant.

DNprediction above median · 1 literature citation
GOFprediction above median · 1 literature citation

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.

Literature Evidence

DNDepletion of endogenous CHMP2B by RNAi resulted in morphological changes similar to those induced by mutant CHMP2B, consistent with dominant-negative activity of pathogenic mutants.PMID:20699355
GOFChromosome 3-linked frontotemporal dementia (FTD3) is caused by a gain-of-function mutation in CHMP2B, resulting in the production of a truncated toxic protein, CHMP2BIntron5.PMID:36414997

Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312.

ClinVar Variant Classifications

0 submitted variants in ClinVar

Protein Context — Lollipop Plot

CHMP2B · 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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