What a test can show
Dedicated CAG-repeat sizing, not a routine SNP panel.
Monogenic conditions
HTTHuntington disease
CAG repeat expansion above clinical thresholds is associated with disease.
RELATIONSHIP VALIDITYHigh: established causality
ACTIONABILITYHigh psychosocial impact; limited preventive utility
SOURCE CHECKLinks and claim boundaries are editorially checked; external expert review is stated only with named disclosure
Practical meaning
Predictive testing should include genetic counselling and informed, voluntary choice.
Where knowledge ends
Testing may predict high disease risk, but not exact onset age or individual course.
SOURCES AND VERSION
Verifiable, not ‘trust us’.
Updated: 14 August 2026. Any clinical interpretation requires the exact variant, testing method, family information and medical context.