ATXN3 Repeat Expansion Testing
Description
Pathogenic CAG repeat expansions in the ATXN3 gene have been associated with autosomal dominant spinocerebellar ataxia 3 (SCA3), also known as Machado-Joseph disease. The pathogenic repeat expansions lead to expanded polyglutamine tracts that cause ATXN3 protein to aggregate and mislocalize in neurons, which may disrupt their function.
Pathogenicity is dependent upon CAG repeat length according to the following ranges 1-4:
Normal Alleles | Mutable Normal Alleles | Intermediate or Uncertain Alleles | Reduced Penetrance Alleles | Full Penetrance Alleles |
44 or fewer | - | 45-49 | 50-55 | 56 or more |
*Repeats in this range may increase the risk for amyotrophic lateral sclerosis.
Tests That Analyze ATXN3 Repeats
- Genomic Unity® 2.0
- Genomic Unity® Whole Genome Analysis
- Genomic Unity® Lightning Genome Analysis – Pediatric
- Genomic Unity® Lightning Genome Analysis – Standard
- Genomic Unity® Exome Plus Analysis
- Genomic Unity® Exome Analysis
- Genomic Unity® Movement Disorders Analysis
- Genomic Unity® Comprehensive Ataxia Analysis
- Genomic Unity® Ataxia Repeat Expansion Analysis
- Genomic Inform®