[Analysis of clinical features and related genes variation in five patients with 46, XX male syndrome]

Objective: To explore the clinical manifestations and molecular features of 46, XX male syndrome. Method: The clinical and molecular data of five 46, XX male syndrome cases treated in the Department of Pediatrics of Shanghai Ruijin Hospital form August 2010 to August 2014 were retrospectively analyzed. Result: The five patients were all sociopsychologically males and came to hospital respectively for short stature, ambiguous genitalia or gynecomastia. They were all below the normal male's average height, and their karyotype was all 46, XX. One case in five was verified as sex determining region of Y chromosome (SRY gene) positive revealed no abnormality in their external genitalia. He had short stature since childhood, whose SRY gene fragments were shown by FISH transferred to the ends of X chromosome. Three cases in four were SRY gene negative with ambiguous genitalia of cryptorchidism and testicular dysplasia to different degrees. The copy number variations of SOX9 gene was found in one case, the loss of heterozygosity area in DHH gene of one case. Another SRY gene negative patient who had normal male external genitalia, came to the hospital due to puberty gynecomastia, that of SOX9 gene and its upstream gene both increased. Conclusion: The main clinical characteristics of 46, XX male syndrome are male phenotype, 46, XX karyotype, gonad of testis or ovotestis and no uterus. In addition, short stature, ambiguous genitalia or gynecomastia can be one reason for hospital visits. SRY gene translocation, SOX9 gene and its upstream gene copy number increase all can lead to 46, XX male syndrome. The cause of some may play an important role in 46, XX male syndrome, but has not yet been determined.