本文报道1例9号染色体臂间倒位三代遗传的家族。孕妇30岁,第3胎孕26周,产前检查羊水培养核型为46,XY,inv(9),有一女为先天呆傻。孕妇及其女血培养核型为46,XX,inv(9),女儿另具21三体,孕妇妹及小弟也各具有1条inv(9),表型均正常,母已亡。但推测倒位染色体系来自母亲。染色体异常的个体是否容易出现21三体的后代有待进一步观察。 This article reports a case of chromosome 9 on the arm of the inverted three generations of the genetic family. Pregnant women 30 years old, the third pregnancy 26 weeks, prenatal examination of amniotic fluid culture karyotype for 46, XY, inv (9), there is a female innate dumb silly. The karyotypes of pregnant women and their female blood were 46, XX, inv (9), and another 21 trisomy of pregnant women. The pregnant women and their wives also each had one inv (9). Their phenotypes were normal and their mothers had died. However, it is assumed that the inverted dye system is from the mother. Chromosomal abnormalities are prone to trisomy 21 progeny to be further observed.