What is the karyotype that you expect in chromosomal studies in a young male with hypogonadism and infeility and suspected Klinefelter syndrome?: (A) 47XXY, (B) 45X0, (C) 46XXY, (D) 45XXX
Answer is A. Klinefelter syndrome is the most common chromosomal disorder associated with male hypogonadism and infeility. It is defined classically by a 47XXY karyotype with variants that demonstrate additional X and Y chromosomes. The syndrome is characterized by hypogonadism (small testes, azoospermia, oligospermia), gynecomastia in late pubey, psychosocial problems, hyalinization and fibrosis of the seminiferous tubules, and elevated urinary gonadotropin levels.