Chromosomal and SRY gene findings by FISH in patients with disorders of sexual development

Objective: Disorders of sexual development are a group of congenital diseases that affect the normal formation of genital structures. Within the pathophysiologic mechanisms described, there are genetic factors caused by chromosomal or sex-determining gene alterations. Therefore, chromosomal analysis is an essential priority in the diagnostic approach. Alterations in the chromosomes and the SRY gene as a cause of disorder of sexual development was analyzed herein. Material and methods: G or R-banding karyotype and FISH analyses for the SRY gene were performed in lymphocytes, gonadal tissue, and scrotal tissue in twelve cases, three cases, and one case, respectively. The clinical information was obtained from the patients' medical reports. Results: In 9 (73%) cases, the assigned sex was male, and in 3 (27%) cases, it was female. Karyotype 46,XY was found in 8 (66%) cases, 46,XX in 2 (17%) cases, and mosaic karyotype in 2 (17%) cases with idic(Y). A single case of gonadal tissue showed mosaicism due to the presence of a tetraploid cell line. The most common clinical diagnosis was abnormal genital differentiation in 8 (67%) cases, followed by hypospadias in 5 (41.7%) cases. Conclusions: The results show the importance of applying different cytogenetic tests in making the diagnosis, and the need for a multidisciplinary team to address the disorder.