JPH3 Repeat Expansion Testing
Description
Pathogenic CTG repeat expansions in the JPH3 gene have been associated with autosomal dominant Huntington disease-like 2 (HDL2).
Pathogenicity is dependent upon CTG repeat length according to the following ranges 1-2:
Normal Alleles | Mutable Normal Alleles | Intermediate/Uncertain Alleles | Reduced Penetrance Alleles | Full Penetrance Alleles |
6-28 | 29-35* | - | 36-39 | 40 or more** |
*Repeats in this range may be unstable and expand in subsequent generations and/or result in reduced penetrance.
**Earlier age of onset is associated with longer repeats.