根据Imaizumi等(1975年)的研究,近年来全日本的近亲结婚频率降低了.在日本的八个地区中也观察到了表(堂)兄妹结婚频率的地理性差异.在日本,关于常染色体隐性疾病的资料通常来自一些大学的医院,在大多数情况下是带有局限性的.所以,估计常染色体隐性基因的频率,应该利用当地人口近亲结婚的频率,而不是全日本 According to studies by Imaizumi et al. (1975), the frequency of marriages of allies in Japan has decreased in recent years.Geographical differences in the frequency of marriages of siblings have also been observed in eight districts of Japan.In Japan, the prevalence of autosomal recessive Disease information often comes from hospitals in some universities, and in most cases is limited, so to estimate the frequency of autosomal recessive genes, we should make use of the frequency of the local population’s close relatives marry rather than all Japan