Question 1 of 164
A 16-year-old girl presents because she has never had a menstrual period. She reports normal breast development beginning at age 11 but has never noticed pubic or axillary hair growth. She is 5 ft 8 in tall. On examination she has Tanner stage 5 breasts, absent pubic and axillary hair, and a blind-ending vaginal pouch with no palpable cervix or uterus. Serum testosterone is in the normal male range. Which of the following is the most appropriate next diagnostic step?