The clinical and genetic study of a family of spinocerebellar atrophy

• Main Authors: Yip, Bak-Sau, 葉伯壽
• Other Authors: Lai Yiu-Kay
• Format: Others
• Language: zh-TW
• Published: 1998
• Online Access: http://ndltd.ncl.edu.tw/handle/83293559127370971274

碩士 === 國立清華大學 === 生命科學系 === 86 === The spinocerebellar degeneration (SCD), also named spinocerebellar atrophy or spinocerebellar ataxia (SCA), are a complex disease comprising of heterogeneous neurologic disorders. The most common clinical features of SCA are disturbances of motor coordination and balance, which imply destruction of anatomical structure, i.e., cerebellum, spinal tracts and brainstem nuclei. Additional degenerative changes may also occur in the eye, cerebrum, basal ganglia, spinal cord and peripheral nerve, on the basis oclinicopathological findings. In general, SCDs could be classified into two groups, the first being those for which a known cause has been identified and the second being those for hereditary disorders. Rarely, cerebellar degeneration is found in patients with ovarian cancer, oat cell carcinoma, breast cancer or lymphoma. Although classifications of SCADs (Spinocerebellar ataxia autosomal dominant) based on clinical and neuropathologic findings have been proposed, it is quite difficult to define the different subtypes of this group of diseases due to the overlapping phenotypes and the variability of the clinical manifestation. Expanded CAG repeat sequences have been identified in the coding region of genes mutated in SCADs. In all disorders, CAG expansion codes for an elongated polyglutamine chain(Torttier Y. et. al., 19). Nowadays, seven different loci associated with SCA have been identified with linkage studies. SCA1maps to chromosome 6p, SCA2 maps to chromosome 12q22-24, SCA3 maps to chromosome 14q24.3, SCA4 maps to 16p22.1, SCA5 maps to chromosome 11, SCA6 maps to chromosome 19 and SCA7 maps to chromosome 3. We study a family of SCAD with four generations in clinical manifestation and genetic study of CAG repeat.