This gene encodes one of the class III myosins. Myosins are ATPases, activated by actin, that move along actin filaments in the cell. This class of myosins are characterized by an amino-terminal kinase domain and shown to be present in photoreceptors. Alternative splicing results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Mar 2014]

OMIMResearchGenerating clinical summary…
MultiplemechanismLOEUF 0.99
Clinical SummaryMYO3B
Population Constraint (gnomAD)
Low constraint (pLI 0.00) — loss-of-function variants are relatively tolerated in the population.
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ClinVar Variants
217 VUS of 255 total submissions

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Tolerant — LoF & missense variants common in population
LoF Constraint?
0.99LOEUF
pLI 0.000
Z-score 1.61
OE 0.81 (0.660.99)
Tolerant

Typical tolerance to LoF variation

Missense Constraint?
0.11Z-score
OE missense 0.99 (0.931.05)
726 obs / 734.3 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios?
LoF OE?0.81 (0.660.99)
00.351.4
Missense OE?0.99 (0.931.05)
00.61.4
Synonymous OE?1.05
01.21.6
LoF obs/exp: 64 / 79.5Missense obs/exp: 726 / 734.3Syn Z: -0.66

This gene — mechanism propensity

DN
0.6938th %ile
GOF
0.6932th %ile
LOF
0.3844th %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
GOFprediction 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

255 submitted variants in ClinVar

Classification Summary

VUS217
Likely Benign15
Benign5
217
VUS
15
Likely Benign
5
Benign

Curated Variants Distribution

Classified variants from ClinVar · 5 ACMG categories

ClassificationLoFMissense + InframeNon-codingSynonymousTotal
Pathogenic
0
0
0
0
0
Likely Pathogenic
0
0
0
0
0
VUS
0
217
0
0
217
Likely Benign
0
9
0
6
15
Benign
0
2
2
1
5
Total022827237

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

View in ClinVar →

18 pathogenic / likely-pathogenic (of 21) ClinVar copy-number / structural variants overlap MYO3B — these span large chromosomal regions, not the gene specifically, and are excluded from the counts above. Explore in CNV tools →

Protein Context — Lollipop Plot

MYO3B · protein map & ClinVar variants

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

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

No active trials found for this gene.

Search ClinicalTrials.gov →