Endocrine Abstracts

The 46 XX male syndrome (de la Chapelle syndrome or 46,XX testicular disorder of sex development -46,XX testicular DSD-) is a rare phenotype associated with disorder of the sex chromosomes. XX males exist in different clinical categories with ambiguous genitalia or partially to fully mature male genitalia, in combination with complete or incomplete masculinization.

Clinical report: We describe the clinical, molecular, and cytogenetic findings of a 26-year-old male patient with 46,XX testicular DSD.

The patient attended our endocrinology clinic with complaints of gynecomastia\. His height was 165 cm and weight 76.6 kg (BMI:28.13 kg/m²). He presented bilateral gynecomastia for the last 7 years. At presentation, hormonal laboratory evaluation revealed elevated serum concentrations of FSH and LH, with low concentrations of Testosterone (230 ng/dl). The testicles were descended in the scrotum but small in size with volumes 3.5 and 4 ml (normal range 18–30 ml). Axillary and pubic hairs were of normal pattern but low density.

Testicular ultrasound revealed testes hypotrophia (right testes: 23.8×14.4×12.5 mm, left testes: 24.7×10.3×16.3 mm)without nodes or calcium intratestes.

Abdominal pelvic ultrasonography (USG) showed normal seminal vesicles and prostate and no mullerian derivatives.

Semen analysis showed azoospermia.

Chromosomal analysis revealed 46,XX karyotype. Fluorescence in situ hybridization (FISH) showed the SRY region translocated to the short arm of the X chromosome. The presence of the SRY gene was also confirmed by polymerase chain reaction (PCR).

Conclusion: The 46,XX testicular DSD is a rare form of sex reversal with complex mechanisms leading to a large spectrum of clinical manifestations ranging from ambiguous genitalia in the newborn to normal male phenotype. Therefore, diagnosis is established either pre- or early postnatal, or in adult life due to male infertility or as in our case, due to gynecomastia.

Our patient has a 46,XX Karyotype, normal male phenotype and hypergonadotropic hipogonadism leading to infertility.