Sex-determining Region of Y-gene Translocation and 46,XX Testicular Disorders of Sex Development: Cytogenetic and Molecular Insights into Male Infertility.

46,XX male syndrome, also known as De la Chapelle syndrome, is a rare condition characterised by a discordance between chromosomal sex and male phenotypic presentation. This study investigates the genetic basis of sex-determining region of Y-gene (SRY)-positive 46,XX testicular disorders of sex development in three male patients presenting with primary infertility and signs of hypogonadism. All patients had azoospermia on semen analysis. Cytogenetic and molecular investigations, including conventional karyotyping, fluorescence in situ hybridisation and polymerase chain reaction, confirmed a 46,XX karyotype with SRY gene translocated onto the short arm of one X chromosome. Y chromosome microdeletion analysis revealed the complete absence of Azoospermia Factor a (AZFa), AZFb and AZFc regions, which correlates with the observed infertility. These findings highlight the role of SRY translocation in initiating the testicular development in 46,XX individuals, while the absence of AZF regions contributes to spermatogenic failure.