46, XX Male Disorder of Sexual Development.

Area of Science:

• Endocrinology
• Genetics
• Reproductive Medicine

Background:

• Primary hypogonadism presents with diverse etiologies, including rare congenital conditions.
• 46,XX male disorder of sexual development (DSD) is an uncommon cause, occurring in approximately 1 in 20,000 male births.
• This condition results from the translocation of the sex-determining region Y (SRY) gene.

Purpose of the Study:

• To present a case of primary hypogonadism diagnosed as 46,XX male DSD.
• To emphasize the diagnostic utility of karyotyping in primary hypogonadism.
• To discuss the management and monitoring of testosterone replacement therapy in this condition.

Main Methods:

• A 47-year-old male with a 9-year history of primary hypogonadism was evaluated.
• Diagnostic workup included baseline hormone levels (testosterone, FSH, LH), physical examination, karyotyping, and fluorescence in situ hybridization (FISH).
• Treatment involved testosterone replacement therapy (testogel) with ongoing monitoring of blood markers and metabolic risk factors.

Main Results:

• The patient presented with low testosterone (4.3 nmol/L) and elevated gonadotropins (FSH 17.5 IU/L, LH 15.2 mIU/ml), alongside short stature and pre-pubertal testes.
• Karyotyping revealed a 46,XX chromosomal complement.
• FISH analysis confirmed the presence of a translocated SRY gene on the X chromosome, establishing the diagnosis of 46,XX male DSD.

Conclusions:

• 46,XX male DSD is a rare congenital cause of primary hypogonadism.
• Karyotyping is a crucial diagnostic tool for identifying 46,XX male DSD in patients with primary hypogonadism.
• Testosterone replacement therapy is the standard treatment, requiring careful monitoring.