328例非特异性精神发育迟滞的隐性基因分析

RECESSIVE GENES IN NON-SPECIFIC MENTAL RETARDATION

采用分离分析和血缘分析方法，对山东省遗传病调查中发现的３２８个父母双方均正常的中、重度非特异性精神发育迟滞（ＮＳＭＲ）家系进行了分析。结果表明，多发家庭先证者的平均近婚系数显著高于一般群体，分离比接近０．２５。提示隐性基因在中、重度ＮＳＭＲ发生中起一定作用。在重度ＮＳＭＲ，散发病例占４０．７％，Ｘ连锁隐性遗传占９．１２％，常染色体隐性遗传占５０．１８％。常染色体隐性基因位点数的最小估计值为２４，各位点的平均基因频率为０．００３５，携带者总频率为１７．５４％；在中度ＮＳＭＲ，散发病例占６１．５％，Ｘ连锁隐性遗传占１１．５３％，常染色体隐性遗传占２６．９７％，常染色体隐性基因位点数的最小估计值为１３２，各位点的平均基因频率为０．００２１，携带者总额率为５４．９５％。

Three hundred twenty-eight pedigrees of non-specific mental retardation from normal parents were analyzed with segregation and consanguinity models. Our results indicate that multiplex families are associated with a high inbreeding coefficient and a segregation frequency close to one-quarter. The genetic constitution of severely retarded offsprings from normal by normal matings is:spormadic cases 40.7%,autosomal recessive 50.8%,X-linked recessive 9.12%.At least,24 loci were involved in the autosomal recessive group.The moderately retarded offsprings consist of 61.5% of sporadic cases,11.53%of X-linked recessive and 26.97% autosomal recessive cases, in which the number of contributory loci is more than 132.