Recently, the Genetics Unit of the Department of Obstetrics and Gynaecology of Zhongshan San Hospital, in collaboration with the Department of Infertility and Sexual Medicine and other related departments, performed genetic diagnosis for several patients whose chromosomal karyotyping results did not match their actual sex. Multiple rare genetic variants were identified, including SRY gene translocation, CYP21A2 gene deletion (described separately) and androgen receptor gene (AR gene) mutant family lines (described separately). Sex reversal syndrome is a human genetic disease that causes abnormal sex development, including 46,XX males and 46,XY females. 46,XX males have a prevalence of 1: 20,000-1:25,000 in males, and its clinical manifestations are mainly infertility after puberty, poor testicular development and other problems while checking chromosomal findings, but the development of external genitalia is mostly more normal, and is almost no obvious difference from normal males before puberty. There is almost no obvious difference, so it is not easy to be found before puberty. Due to the complexity of the process of sex determination and sex differentiation, patients with male sex reversal syndrome of this disease show obvious heterogeneity in genetics and clinical manifestations, and this heterogeneity brings difficulties in clinical diagnosis. Due to the limitation of the existing technology, domestic research institutes are usually only able to detect the SRY gene, but are unable to detect and analyze the other multiple pathogenic genes. The Obstetrics Genetics Unit, through extensive preliminary work, has established a universal testing process for sex reversal syndrome, which, in addition to the SRY gene, is capable of comprehensively analyzing sex abnormalities caused by copy number variations in a variety of genes, including DSS, DAX1, WNT4, SOX9, NR5A1, CYP21A2, and other genes, in order to make a reliable genetic diagnosis. Figure 1: The result of karyotype analysis is 46,XX (female karyotype) Figure 2: The result of genetic screening shows the existence of abnormalities in the SRY gene Figure 3: FISH gene localization confirms that the SRY gene (which is supposed to be located on the Y chromosome) is easily located on the short arm of the X chromosome