先天性智力低下的病因及发病风险的研究

A study on pathogenesis and inheritance risk of congenital mental retardation

目的 :探讨与先天性智力低下发病有关的遗传因素。方法 :对 84 0例先天性智力低下患者进行生化检查、家系分析和细胞遗传学分析。结果 :(1)单基因遗传病引起的智力低下 2 1例 ,占 2 .5 0 % ,其中AR病 18例、AD病 1例、XR病 2例 ;(2 )染色体异常引起的智力低下 2 16例 ,占 2 5 .71% ,其中Down综合征 5 4例、Fra(X)综合征 138例、其他染色体异常 2 4例 ;(3)多基因遗传病引起的智力低下 13例 ,占 1.5 5 % ;(4 )原因不明的智力低下 5 90例 ,占 70 .2 4 %。结论 :先天性智力低下具有复杂的遗传学病因和发病机制 ,提示遗传和环境因素对智力低下的产生都起着重要的作用。

Objective:To investigate the genetic factors relating to mental retardation (MR).Methods:We have analysed 840 cases of congenital mental retardation with biochemistry lab tests,cytogenetic study and family investigation.Results:21 cases were due to monogenic disorders (2.50%);216 cases were due to chromosomal diseases (25.71%);13 cases were due to polygenic disorders (1.55%);590 cases were due to unknown causes (70.24%).Conclusion:It suggested that occurrence of mental retardation is related to both genetic factors and environmental factors.