[Klinefelter syndrome].

Klinefelter's syndrome is defined by males with at least one Y chromosome and at least two X chromosomes. It represents the most common major abnormality of sexual differentiation. The original description was characterized by eunuchoidism, gynecomastia, azoospermia, and small, firm testes. Patients tend to be taller than average, mainly because of the disproportionate length of their legs. Serum testosterone is low to normal and gonadotropins are elevated. Histologically, seminiferous tubules degenerate and are replaced with hyaline. Some complications are occasionally found such as neoplasm, osteoporosis, autoimmune diseases, and diabetes mellitus. Treatment options include testosterone replacement for correction of the androgen deficiency. Recently, intracytoplasmic sperm injection(ICSI) of testicular spermatozoa resulted in several deliveries.