J Korean Child Neurol Soc.
2000 Dec;8(2):329-332.
A Case of Juvenile Onset Spinocerebellar Ataxia Type 3
- Affiliations
-
- 1Department of Neurology, College of Medicine, The Catholic University of Korea, Seoul, Korea.
- 2Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Abstract
- The genetic locus of spinocerebellar ataxia type 3 (SCA3) is linked to chromosome 14q
24.3-qter like Machado-Joseph disease (MJD). The number of CAG repeats on mutant
chromosome correlates positively with severity of disease, and negatively with the age of
onset. However, the interindividual variation cannot be explained solely by the size of
CAG repeats. We experienced a patient of juvenile onset SCA3, who had a relatively small
length of CAG repeats. Several factors may have contributed in determining the age of on
set in our case. The normal allele or modifying gene at other loci may have relationship
with the age of onset and phenotype. Also, it should be considered that size of the expanded
repeat in lymphocyte could be different from the size in cells of involved structures.