性染色体异常是导致性腺发育不良和生殖器官先天发育畸形的重要原因之一。近年来关于大Y染色体产生的临床效应曾有争论,有些学者认为大Y是一种正常的多态变异,无临床意义;还有的研究提示,大Y是来自Y异染色质中DNA过多的重复,造成有丝分裂发生错误或影响基因调节及细胞分化,从而 Sexual chromosomal abnormalities are one of the important causes of gonad dysplasia and congenital malformations of genital organs. In recent years, the clinical effect of large Y chromosome has been controversial, some scholars believe that large Y is a normal polymorphic variation, no clinical significance; there are studies suggest that large Y is derived from Y heterochromatin in excess The duplication, resulting in mitosis or affect the gene mutation and cell differentiation, thus