A Case of Spinocerebellar Ataxia Type 6

J Korean Neurol Assoc > Volume 18(3); 2000 > Article

Journal of the Korean Neurological Association 2000;18(3): 345-348.

척수소뇌성 실조증 6형 1예

이태연 이성현 이상수 한설희신동익, 이태연 이성현 이상수 한설희신동익

충북대학교 의과대학 신경과학교실

A Case of Spinocerebellar Ataxia Type 6

Dong-Ick Shin, M.D., Tai-Yeon Lee, M.D., Sung-Hyun Lee, M.D., Sang-Soo Lee, M.D., Seol-Heui Han, M.D.

Department of Neurology, Chungbuk National University Hospital

Abstract

Spinocerebellar ataxia (SCA) type 6 was recently identified as a form of autosomal dominant cerebellar ataxia asso-ciated with the small expansion of CAG repeats. The number of CAG repeats varies from 4 to 18 on normal alleles and 21 to 30 on the SCA type 6 chromosome. SCA type 6 is characterized by cerebellar ataxia and dysarthria associated with cerebellar atrophy. Many patients with SCA type 6 have horizontal gaze-evoked nystagmus, and some have a lim-itation of eye movements on the upward and lateral gaze. A 59-year-old woman without any noticeable family history presented with slowly progressive cerebellar ataxia, dysarthria, and oscillopsia. She had vertical nystagmus and hori-zontal gaze-evoked nystagmus. Brain MRI revealed a moderate cerebellar atrophy, most prominent in the vermis, with relative sparing of the brain stem. A genomic polymerase chain reaction (PCR) analysis showed 24 CAG repeats at the SCA6 locus compatible with the sporadic SCA type 6. J Korean Neurol Assoc 18(3):345~348, 2000 Key Words : SCA6, CAG repeats, PCR