HSPB3

Chr 5AD

heat shock protein family B (small) member 3

Also known as: DHMN2C, HMN2C, HMND4, HSPL27

This gene encodes a muscle-specific small heat shock protein that inhibits actin polymerization. Mutations cause autosomal dominant distal hereditary motor neuropathy type 2C, a condition affecting the peripheral motor neurons and resulting in distal muscle weakness. The gene is not highly constrained against loss-of-function variants, and inheritance follows an autosomal dominant pattern.

OMIMResearchSummary from RefSeq, OMIM, UniProt
MultiplemechanismAD1 OMIM phenotype
Clinical SummaryHSPB3
📋
ClinVar Variants
9 unique Pathogenic / Likely Pathogenic· 61 VUS of 100 total submissions
Some data sources returned errors (1)

gnomad: Error: gnomAD API error: 502

Population Genetics & Constraint

Constraint data not available from gnomAD.

DN
0.6936th %ile
GOF
0.73top 25%
LOF
0.3744th %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

100 submitted variants in ClinVar

Classification Summary

Pathogenic8
Likely Pathogenic1
VUS61
Likely Benign18
Benign7
Conflicting5
8
Pathogenic
1
Likely Pathogenic
61
VUS
18
Likely Benign
7
Benign
5
Conflicting

Curated Variants Distribution

Classified variants from ClinVar · 5 ACMG categories

ClassificationLoFMissense + InframeNon-codingSynonymousTotal
Pathogenic
0
0
8
0
8
Likely Pathogenic
0
0
1
0
1
VUS
4
38
17
2
61
Likely Benign
0
3
3
12
18
Benign
0
1
4
2
7
Conflicting
5
Total4423316100

LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly

View in ClinVar →

Protein Context — Lollipop Plot

HSPB3 · 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.

Search ClinicalTrials.gov →
Clinical Literature
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