F8A3
Chr Xcoagulation factor VIII associated 3
Also known as: HAP40
The protein functions as a RAB5A effector molecule involved in early endosome trafficking, mediating recruitment of huntingtin protein and regulating endosome motility through interactions with actin filaments and microtubules. No specific diseases have been definitively associated with mutations in this gene, despite its conservation across species suggesting biological importance. The gene is located on the X chromosome as part of a repetitive region, though clinical significance and inheritance patterns remain to be established.
Population Genetics & Constraint
Constraint data not available from gnomAD.
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.
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
F8A3 · protein map & ClinVar variants
Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.
3D Protein StructureAlphaFold
External Resources
Links to major genomics databases and tools
Clinical Trials
Active and recruiting trials from ClinicalTrials.gov
No active trials found for this gene.
Search ClinicalTrials.gov →No open access results found
External Resources
Links to major genomics databases and tools