Saito T
Department of Child Ecology, National Children's Medical Research Center, Tokyo, Japan.
Genet Epidemiol. 1988;5(6):421-32. doi: 10.1002/gepi.1370050606.
A recent decline in consanguineous marriages in Japan should have resulted in a decrease in the incidence of autosomal recessive disorders. Theoretical estimates were made of the chronological decrease in the incidence using a formula for Hardy-Weinberg expectation in a partially inbred population and applying appropriate consanguinity rates, taken from the literature, during the period from 1942 to 1983. Theoretically estimated also, using Nei's extended Dahlberg's formula, is a chronological decrease in the proportion of first-cousin marriages among the parents of affected individuals. The estimated decrease in both indices during the period was substantial, and greater in disorders of low gene frequencies. The incidence of major autosomal recessive disorders was estimated to have decreased by 40 to 80% during the period. The proportion of first-cousin marriages among the parents of affected individuals dropped from 40-70% in 1945 to 5-15% in 1983. Theoretical estimates of the magnitude of the decrease in the incidence and in the proportion of first-cousin marriages among the parents agreed fairly well with those of observed figures in phenylketonuria and Wilson's disease.
日本近期近亲结婚率的下降本应导致常染色体隐性疾病发病率的降低。利用部分近亲繁殖人群中哈迪-温伯格期望公式，并应用从文献中获取的1942年至1983年期间的适当近亲结婚率，对发病率随时间的下降进行了理论估计。同时，使用内氏扩展达尔伯格公式，对患病个体父母中表亲婚姻比例随时间的下降也进行了理论估计。在此期间，这两个指标的估计下降幅度都很大，在低基因频率疾病中下降幅度更大。据估计，在此期间主要常染色体隐性疾病的发病率下降了40%至80%。患病个体父母中表亲婚姻的比例从1945年的40%-70%降至1983年的5%-15%。发病率下降幅度以及患病个体父母中表亲婚姻比例下降幅度的理论估计值，与苯丙酮尿症和威尔逊氏病的观察数据相当吻合。
