Sex reversal syndrome (46,XX male) in an infertile male

46,XX male sex reversal syndrome, or de la Chapelle syndrome, is a rare chromosomal abnormality related to male infertility. A 39-year-old male was referred for cytogenetic analysis because of primary hypogonadism and infertility. He had a normal male phenotype, mild gynecomastia and small testicles. Conventional cytogenetic analysis was performed on peripheral blood lymphocytes, and further investigation followed using molecular techniques. Karyotypic analysis showed a 46,XX karyotype in all metaphases examined. Polymerase chain reaction (PCR) and fluorescence in situ hybridization (FISH) techniques confirmed the presence of two X chromosomes and revealed the presence of the sex-determining region Y (SRY) gene on the short arm of one X chromosome, and the absence of all azoospermia factor (AZF) genetic regions. It is evident that men with primary hypogonadism and normal phenotype should undergo conventional cytogenetic analysis and, in the case of a 46,XX karyotype, further molecular testing should follow for the detection of the SRY gene.