Cytogenetics and molecular genetics of patients with disorder of sex deve-lopment

AIM: To explore the cytogenetics and molecular genetics of the patients with disorder of sex deve-lopment. METHODS: Three patients of 46, XX male sex-reversal syndrome and 1 patient of female pseudoherma-phroditism received gene copy number detection of sex-determining region Y gene (SRY), CYP21A2, DSS, DAX1, WNT4, SOX9, NR5A1 by multiplex ligation-dependent probe amplification (MLPA). Fluorescence in situ hybridization (FISH) analysis was also performed to map the genes using the probes from the bacterial artificial chromosome (BAC) clone. RESULTS: The single-copied SRY gene was detected by MLPA among the 3 patients of 46, XX male sex-reversal syndrome. FISH analysis revealed that there were double X chromosomes, and SRY gene was translocated to the short arm of one of the X chromosomes. Chromosome analysis of the mother of the female pseudoherma-phroditism patient was 46, XX, whose MLPA analysis showed loss of heterozygosity at CYP21A2-ex03 and amplification at CYP21A1P-ex02. Chromosome analysis of her father was 46, XY, whose MLPA analysis revealed loss of heterozygosity at CYP21A2-ex01 and CYP21A2-ex03,and amplification at CYP21A1P-ex02 and CYP21A1-ex10. CONCLUSION: Sex determination is a process controlled by SRY gene and other genes also participate in. The copy number detection of SRY gene and other genes by MLPA contributes to determine the etiology of the patients with disorder of sex development.