In Klinefelter syndrome, all are true except: (A) Negative feedback on FSH and LH are lost, (B) Decreased Androstenedione levels, (C) Hypoplastic male external genitalia, (D) Most common cause of primary testicular failure
Answer is B. In Klinefelter syndrome, since testosterone levels are decreased, negative feedback on FSH and LH is lost.
Increased FSH stimulates Leydig cells, thereby causing elevated levels of Androstenedione.