脊髓小脑共济失调一家系的遗传学研究

A family with spinocerebellar ataxia.

脊髓小脑共济失调是一种以运动失调为主要症状,以小脑及其传入、传出途径变性为主的疾病,具有很强的遗传异质性,目前已定位的遗传位点超过20个,但目前只有12个基因被成功克隆.文章报道一脊髓小脑共济失调家系,出现患者4代15人,发病年龄在35～50岁左右,家系成员有早发现象.部分成员未到发病年龄,以后有可能出现更多的患者.经遗传分析,该家系的遗传方式为常染色体延迟显性遗传.

Objective： The clinical features of spinocerebellar ataxias （SCAs） are caused by degeneration of the cerebellum and its afferent and efferent connections. In addition to cerebellar signs, there are upper motor neuron signs, extensor plantar responses, and atrophy of the dorsal columns and spinocerebellar tracts. SCAs are autosomal dominant cerebellar degenerative disorders with high genetic heterogeneity. Although at least 20 loci have been mapped, only 12 genes had been cloned successfully. It is now believed that there are loci that have not been identified. Method and Result： In a pedigree with SCA we collected, there are 15 patients in 4 generations. The age of onset is from 35 to 50 years old which showed the phenomenon of anticipation. Some members have not reached age of onset, and cannot be diagnose definitely. Conclusion ： The model of heredity in this family is delayed autosomal dominant heredity.