上海人群面肩肱型肌营养不良症相关位点的D4Z4多态性

目的 对上海人群4p35位点D4Z4重复序列进行研究，分析D4Z4的多态性。方法 191名正常上海人的基因组DNA经EooR I/Bln I双酶水解后，应用脉冲场凝胶电泳及Southem印迹测定其染色体4p35位点的D4Z4片段长度，并对短的D4Z4片段Kpn I酶进行部分酶切以计数其D4Z4串联重复序列数。结果 在191名正常上海人群中，有17人（占8.9％）携带短的D4Z4片段，其长度在22－34kb之间；其中16人携带的短D4Z4片段位于4q35位点，1人携带的短D4Z4片段为4q35→10q26。结论 面肩肱型肌营养不良症的发病虽与4q35位点D4Z4片段的串联重复序列数减少有关，但上海人群中携带4q35位点短的D4Z4片段个体的比例明显高于西方人群，提示其他因素可能也参与面肩肱型肌营养不良症的发病。

Polymorphism of the D4Z4 locus associated with facioscapulohumeral muscular dystrophy 1A in Shanghai population

OBJECTIVE: To investigate the D4Z4 repeats on chromosome 4q35 in normal individuals in Shanghai and analysis the polymorphism of the D4Z4 locus. METHODS: The length of D4Z4 repeats on chromosome 4q35 in 191 normal individuals in Shanghai was determined by pulsed-field gel electrophoresis and Southern blotting after double digestion with Eco RI and Bln I. The number of short D4Z4 repeats was counted after partial digestion with Kpn I. RESULTS: Among 191 normal individuals in Shanghai, seventeen showed the size of D4Z4 fragments ranged from 22 to 34 kb, i.e. 8.9% of individuals had fewer numbers of D4Z4 repeats. Of these 17 individuals, sixteen showed the short D4Z4 fragment on chromosome 4q35, and one low D4Z4 fragment was correlated to 4q35--> 10q26 translocation. CONCLUSION: The frequency of individuals having fewer numbers of D4Z4 repeats on chromosome 4q35 in Shanghai population is higher than that in Caucasian population although the short D4Z4 fragment on chromosome 4q35 is associated with facioscapulohumeral muscular dystrophy. These findings suggest that other factors may also contribute to facioscapulohumeral muscular dystrophy.