Spinocerebellar ataxia type 10 (SCA10) is an autosomal dominant disorder characterized by cerebellar ataxia and seizures. Most patients develop unsteady gait as the first symptom, while others may present with seizures. The age of onset is usually the third or fourth decade, although the disease can start in childhood. Earlier onset in successive generations, which is indicative of anticipation, has been documented. Dysarthria and dysphagia develop, as with the other SCAs. The mutation associated with SCA10 was recently identified as a pentanucleotide repeat expansion in the SCA10 (also known as E46) gene that maps to chromosome 22q13-qter. This pentanucleotide (ATTCT) repeat is located at intron 9 of the SCA10 gene. Normal individuals are found to have a range of 10-29 repeats, while affected individuals exhibit allele sizes greater than 800 repeats. Molecular testing for the SCA10 pentanucleotide expansion mutation is available from the Baylor DNA Diagnostic laboratory by PCR and Southern analyses. Reasons for Referral:
We recommend that genetic and/or psychological counseling be made available to all patients considering having confirmatory or predictive testing for SCA10. Testing Methodology:Direct Mutation Analysis: PCR analysis across the ATTCT region of the SCA10 gene to determine allele sizes. All normal sized alleles and the vast majority of expanded alleles will be detected in this analysis. Southern analysis is used to identify extremely large ATTCT repeat expansions. Allele-size ranges are subject to change as more information becomes available. Sensitivity:~99% detection of the expansion mutation when present. Specimen Requirements:Blood: EDTA (purple-top) tubes: Adults: 14
cc; Child: 6
cc; Infant: 2-3 cc Turnaround Time:3 weeks CPT Codes and Prices:83898, 83891, 83892, 83894x2, 83896, 83897, 83912 References:1. Matsuura T, et al. (2000) Nat. Genet. 26: 191-194. Shipping InformationForms: >> DNA
Requisition Test Codes:
Index: 6055 |