A 16-year-old girl has primary amenorrhoea, height well below the third percentile, a webbed neck, and widely spaced nipples. Ultrasound shows a small uterus with streak ovaries. Which karyotype and hormonal profile combination is most likely?

• A 45,X with elevated FSH and low estradiol ✓
• B 46,XY with normal testosterone and absent uterus
• C 46,XX with low FSH and low estradiol
• D 47,XXY with elevated FSH and normal estradiol

Explanation

Turner syndrome (45,X) causes streak gonads devoid of follicles, so ovarian oestradiol production fails and the pituitary responds with markedly elevated FSH, producing hypergonadotropic hypogonadism. Short stature, webbed neck and shield chest are characteristic somatic features. The 46,XY option describes androgen insensitivity or Swyer syndrome, both covered elsewhere, and 47,XXY is Klinefelter syndrome affecting phenotypic males. Breast development in Turner syndrome is typically poor unless oestrogen is given.

Reference: Nelson Textbook of Pediatrics, 22nd ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.