A 16-year-old girl has primary amenorrhoea. Height is 142 cm, below the third centile, with a wide carrying angle and a low posterior hairline. Breasts are Tanner stage II bilaterally. Serum FSH is 68 IU/L, LH 30 IU/L, estradiol 15 pg/mL. Ultrasound shows a small uterus with streak ovaries. What is the most likely karyotype?

• A 46,XX
• B 47,XXY
• C 46,XY
• D 45,X ✓

Explanation

Short stature with streak gonads, hypergonadotropic hypogonadism, and somatic features such as a low hairline and cubitus valgus is classic Turner syndrome, most commonly 45,X. The elevated FSH distinguishes it from hypothalamic causes. 46,XY would fit complete androgen insensitivity or Swyer syndrome, but both show normal or tall stature, not the characteristic short stature seen here.

Reference: Williams Gynecology, 4th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.