精神发育迟滞 (ＭｅｎｔａｌＲｅｔａｒｄａｔｉｏｎ ,ＭＲ)是指出生前后各种病因造成的智能发育障碍性疾病。我国儿童患病率城市约 1% ,农村约 2 %～ 3 % [1] 。ＭＲ病因复杂 ,弄清其在群体中发病的规律和病因 ,不仅对于指导优生优育和防治工作具有实践意义 ,对于病因学研究也 Mental Retardation (Mental Retardation, MR) is a mental retardation disorder caused by various causes before and after birth. The prevalence rate of children in cities in China is about 1%, and in rural areas about 2% ~ 3% [1]. MR etiology is complex, to understand its pathogenesis in the population rules and etiology, not only for guiding eugenics and prevention and control of practical significance, for etiological studies