Central precocious puberty as a prelude to hypogonadism in a patient with Klinefelter syndrome

Incomplete pubertal development is a common phenomenon found in patients with Klinefelter syndrome (KFS). KFS combined with central precocious puberty (CPP) rarely occurs. We herein report a rare case of KFS with CPP and review several studies to determine the possible mechanism underlying this condition.

An 8-year, 5-month-old male patient was admitted to our hospital because of enlargement of the penis and small testes. Laboratory evaluation revealed high luteinizing hormone and follicle-stimulating hormone levels, a high testosterone level, and the 48,XXYY karyotype. He was treated with triptorelin. One year later, the patient's testosterone level decreased and pubertal arrest occurred.

The literature review in this study showed that the occurrence of hypogonadism combined with CPP is not unique to patients with KFS; it has also been reported in individuals with Turner syndrome, adrenal hypoplasia congenita, and other diseases. Such individuals share common features including partial hypogonadism and a normal hypothalamic-pituitary-gonadal axis. CPP is considered a prelude to hypogonadism, and treatment with a gonadotropin-releasing hormone agonist may prevent gonadal failure.