CACNA1A Repeat Expansion Testing
Description
Pathogenic CAG repeat expansions in the CACNA1A gene have been associated with autosomal dominant spinocerebellar ataxia 6 (SCA6). The pathogenic repeat expansions lead to an expanded polyglutamine tract which may be toxic and/or diminish CACNA1A transcriptional function.
Pathogenicity is dependent upon CAG repeat length according to the following ranges 1-2:
Normal Alleles | Mutable Normal Alleles | Intermediate or Uncertain Alleles | Reduced Penetrance Alleles | Full Penetrance Alleles |
18 or fewer | - | 19 | - | 20-33 |
Note: As SCA6 is typically adult onset, CACNA1A repeat expansions are not reported in minors in comprehensive analyses.
Tests That Analyze CACNA1A Repeats
- Genomic Unity® 2.0
- Genomic Unity® Whole Genome Analysis
- 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 Unity® Epilepsy Analysis
- Genomic Inform®