An 18-year-old white woman presents because she has never had a period.
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
Which laboratory test is most likely to reveal the cause of this patientâ€™s
A. Serum prolactin
B. Serum testosterone
C. Karyotype analysis
D. Serum estradiol
E. Serum thyroid-stimulating hormone
Most correct answer/comments.
correct answer is C
patient presents with primary amenorrhea, short stature, failure of development
of secondary sexual characteristics, and somatic abnormalities suggestive of
Turnerâ€™s syndrome (gonadal agenesis). This condition is most often caused by an
XC genotype, which is readily diagnosed by standard karyotype analysis.
Patients with androgen resistance syndrome may also present with primary
amenorrhea and have male level testosterone values and an XY karyotype, but
they have adequate breast development, normal stature, and no somatic
abnormalities. Patients with hyperprolactinemia may present with primary or
secondary amenorrhea, and they have normal stature and no somatic
abnormalities. Patients with primary hypothyroidism may present with amenorrhea
or precocious puberty, with or without growth retardation but without somatic
abnormalities. Low serum estradiol is a nonspecific finding in all cases of
amenorrhea with reduced pituitary or ovarian function.