An 18-year-old white woman presents because she has never had a period.
An 18-year-old white woman presents because she has never had a period. She was born by normal spontaneous vaginal delivery after a normal full-term gestation. She has always been small for her age but does well in school, plays soccer without difficulty, and has had no intercurrent illness. She has adequate nutritional intake. Her mother, who is 53 years of age, had a normal menarche at 12 years of age, and a sister, who is 20 years old, is taller than the patient, had menarche at 13 years of age, and has regular menses. The patientâ€™s mother has Hashimotoâ€™s thyroiditis.
Physical examination reveals a height of 145cm (57 in) and a body weight of 45 kg (107 Ib). Blood pressure is 97/70 mm Hg. She has a low-set hairline, widely spaced nipples, no significant breast tissue, and scanty axillary and pubic hair.
Which laboratory test is most likely to reveal the cause of this patientâ€™s amenorrhea?
A. Serum prolactin
B. Serum testosterone
C. Karyotype analysis
D. Serum estradiol
E. Serum thyroid-stimulating hormone