Referenced in: none

Automatically associated channels: Cav2.1

Title: SCA8 repeat expansion: large CTA/CTG repeat alleles are more common in ataxic patients, including those with SCA6.

Authors: Yuishin Izumi, Hirofumi Maruyama, Masaya Oda, Hiroyuki Morino, Takayuki Okada, Hidefumi Ito, Iwao Sasaki, Hiroyasu Tanaka, Osamu Komure, Fukashi Udaka, Shigenobu Nakamura, Hideshi Kawakami

Journal, date & volume: Am. J. Hum. Genet., 2003 Mar , 72, 704-9

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/12545428

Abstract
We analyzed the SCA8 CTA/CTG repeat in a large group of Japanese subjects. The frequency of large alleles (85-399 CTA/CTG repeats) was 1.9% in spinocerebellar ataxia (SCA), 0.4% in Parkinson disease, 0.3% in Alzheimer disease, and 0% in a healthy control group; the frequency was significantly higher in the group with SCA than in the control group. Homozygotes for large alleles were observed only in the group with SCA. In five patients with SCA from two families, a large SCA8 CTA/CTG repeat and a large SCA6 CAG repeat coexisted. Age at onset was correlated with SCA8 repeats rather than SCA6 repeats in these five patients. In one of these families, at least one patient showed only a large SCA8 CTA/CTG repeat allele, with no large SCA6 CAG repeat allele. We speculate that the presence of a large SCA8 CTA/CTG repeat allele influences the function of channels such as alpha(1A)-voltage-dependent calcium channel through changing or aberrant splicing, resulting in the development of cerebellar ataxia, especially in homozygous patients.