THE IDENTIFICATION OF SRY GENE AS A CLINICAL INVESTIGATIVE TOOL FOR SEX AMBIGUITY: AN EXPERIENCE IN H.U.S.M.

Nine newborns and infants with sex ambiguity and congenital adrenal hyperplasia (CAH) were analysed for the presence of the testis-determining factor (TDF). They required an urgent genetic evidence for a sex assignment both for clinical management and parental request. The sex-determining region on Y chromosome (SRY gene) was used as a molecular marker in combination with the Fluorescence in situ hybridization (FISH) to identify the chromosome X and Y material on the interphase cells to complement the conventional karyotyping. The molecular analysis of SRY gene to define the association with the testicular-determining factor (TDF) supports the presence of the Y chromosome material. Our results showed that the sex genetics of the newborns were assigned then as male and female respectively and one newborn was reassigned as female. In the nine samples that we carried out the SRY analysis, seven showed the presence of SRY gene and in two samples it was absent. Sex assignment earlier not determined by the clinicians in three patients showed the presence of SRY gene in two patients while one was absent. All these sex reassignment and confirmation were supported by the molecular-cytogenetics and karyotyping studies. This approach provided a fast sex genetic information when the hormonal assay and karyotyping were not available and/or delayed. It is very useful to complement an immediate information for the clinicians to rule out cases of ambiguous genitalia due to CAH and subsequently clinical investigations that affects the long term management.