| Summary: | 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.
|
|---|
