正常中国人和DMD患者X染色体Xp~(21)区的RFLP研究

本文应用从人类X柒色体Xp~(21)区不同部位分离得到的9种DNA探针,分析了100名正常中国人,38名DMD患者及其母亲X柒色体Xp~(21)区的14个限制性位点多态性(RSP;又称限制性片段长度多态性,RFLP)。发现正常的X染色体与携带DMD基因的X染色体Xp~(21)区的RFLP频率没有明显差别;在38例DMD患者中有7例的X染色体有DNA片段缺失;在本文分析的24例患者母杀中有17例是DMD基因携带者,她们在Xp~(21)区的RFLP均存在杂合的多态性,因此可以应用RFLP连锁分析对这些家系进行DMD的产前诊断。

RESTRICTION FRAGMENT LENGTH POLYMORPHISMS ON Xp21 REGION OF THE X CHROMOSOME IN NORMAL CHINESE AND DMD PATIENTS

Duchenne muscular dystrophy (DMD) is an X linked recessive muscle disor der, with an incidence of approximately 1 in 3,000 newborn males. The patient is characterised by progressive wasting of the skeletal muscles and usually die of respiratory difficulties by the age of 20. The locus for DMD was mapped to the short arm of the X chromosome at band Xp21. In the present study, 14 polymorphic sites were analysed in the Xp21 region of X chromosomes of 100 normal Chinese and 38 unrelated DMD patients and their mothers, using nine probes isolated from Xp21. The results showed (1) there was no significant difference between the frequence of RFLP in the normal X chromosomes and that in the DMD patients' X chromosomes; (2) there were 7 DMD patients (18.4% of the total) where a DNA deletion was detected; (3) 17 patients' mothers (17 out of 24 mothers analysed) were the carriers for DMD gene, all of them were with the heterogeneity of polymorphic DNA markers in Xp21, so prenatal diagnosis of Duchenne muscular dystrophy can be carried out in these families using RFLP linkage analysis.