本文通过对6个家系8例先天性绕核性白内障的临床综合观察分析,认为其致病是由于血族婚姻使得杂合子相遇而造成的。此外,作者应用概率计算,对血族婚姻更易造成罕见遗传病这一现象进行了探讨,推导出3条公式以用于血族婚姻时的各种计算。文中并就我国自古以来对近亲婚配的认识问题提出了作者个人的粗浅见解。 Based on the comprehensive clinical observation and analysis of 8 cases of congenital nucleus-cataract in 6 pedigrees, this paper argues that the pathogenicity is caused by the encounter of heterozygotes caused by kinship marriages. In addition, the author uses probabilistic calculation to explore the phenomenon that kinship marriage is more likely to cause rare genetic diseases. Three formulas are deduced for various calculations in kinship marriages. In the article, the writer’s personal opinions are put forward on the cognition of the marriage between inces in our country since ancient times.