人类遗传学,特别是细胞遗传学于近年来发展很快,积累了很多资料;细胞染色体的普通分析和新技术的应用,例如显带染色体的观察使许多遗传性疾病的诊断更为明确。治疗和预防这些疾病也有捉高。染色体异常引起的疾病是颇常见的。在妊娠早期自动流产物质中的染色体异常占50％。新生活婴中的1/175～1/150甚至1/100有染色体异常,其中一半为性染色体畸变。性染色体异常可引 Human genetics, especially cytogenetics, has developed rapidly in recent years and has accumulated a great deal of information. Common analyzes of cell chromosomes and the application of new technologies, such as the observation of the chromosomes, make the diagnosis of many genetic diseases more explicit. The treatment and prevention of these diseases have also been elevated. Chromosomal disorders caused by the disease is quite common. Chromosome abnormalities in spontaneous abortion material in early pregnancy are 50%. Newborn babies 1/175 ~ 1/150 or even 1/100 have chromosomal abnormalities, of which half are sex chromosome aberrations. Sexual chromosomal abnormalities can be cited