Medicine>>>>>Endocrinology and Metabolic Disease
Question 27#

A 24-year-old man presents with gynecomastia and infertility. On examination, he has small, firm testes and eunuchoid features. He has scant axillary and pubic hair. Which of the following is correct?

a. The patient has Turner syndrome
b. The patient will have a normal testosterone level
c. His most likely karyotype is 47 XXY
d. The patient will have normal sperm count
e. The patient is likely to have low levels of gonadotropins

Correct Answer is C

Comment:

The picture of infertility, gynecomastia, and tall stature (arms and legs longer than expected for truncal size) is consistent with Klinefelter syndrome and an XXY karyotype. The patient has abnormal gonadal development with hyalinized testes that result in low testosterone levels. Pituitary function in Klinefelter syndrome is normal, so gonadotropin levels are elevated in response to underproduction of testosterone. Although Klinefelter patients may have sexual function, they do not produce sperm and are infertile. Turner syndrome refers to the 45 XO karyotype that results in abnormal sexual development in a female.