Rett综合征的X染色体失活类型及其线粒体DNA的初步研究

PRELIMINARY ANALYSIS OF X CHRO-MOSOHE INACTIVE PATTERNS AND MI-TOCHONDRIAL DNA IN RETT SYNDROME

对１９例Ｒｅｔｔ综合征患儿进行了临床随访及家族史调查，并利用Ｓｏｕｔｈｅｒｎ杂交及聚合酶链反应技术，对１２例患儿和１１例患儿母亲的Ｘ染色体失活类型及８例患儿的线粒体ＤＮＡ的部分区域进行了初步研究。结果显示，患儿母亲的流产率及死胎率无增高；患儿及母亲的Ｘ染色体非随机失活的比率较高，３例Ｘ染色体非随机失活的母亲均将其失活的Ｘ染色体遗传给患儿，提示Ｘ染色体非随机失活在该病的遗传过程中起一定作用；未发现线粒体ＤＮＡ有大的缺失。以上工作尚需更多病例加以证实。

e followed-up 19 Rett syndrome children andanalvsed X chromosome inactive patterns in 12 patientsand 11 mothers by Southern blot hybridization. We alsoanalysed some regions of mitochondrial DNA sequencein 8 patients by polyrnerase chain reaction (PCR). Theresults showed that in patients' mothers, the sponta-neous abortion rate and the stillbirth rate were nothigher than that of general population. The percentageof non-random X chromosome inactivation increased inpatients and their mothers. All threenon-random Xchromosome inactive mothers transmitted their inactiveX chromosome to their daughters, and became active in2 daughters. The results suggest that non-random Xchromosome inactivation play a part in the inheritance ofRett syndrome. No large scale deletion has been foundin patients' mitochondrial DNA by PCR analysis. Accu-mulation of more cases is needed to confirm the abovestudies.