A 16-year-old girl presents with primary amenorrhoea. Height is 145 cm (below third centile), breasts are Tanner stage II, and there is sparse pubic hair. Ultrasound shows a small uterus with streak gonads. Serum FSH is 68 IU/L and estradiol is 20 pg/mL. What is the most likely diagnosis?

• A Turner syndrome (45,X gonadal dysgenesis) ✓
• B Complete androgen insensitivity syndrome
• C Constitutional delay of puberty
• D Kallmann syndrome

Explanation

Short stature, streak gonads, infantile sexual development and markedly elevated FSH indicate hypergonadotropic hypogonadism from 45,X gonadal dysgenesis. The elevated FSH excludes constitutional delay and Kallmann syndrome, both hypogonadotropic states with low gonadotropins. Androgen insensitivity is excluded because testosterone-driven pubic hair would be absent and height would be normal or tall, not short.

Reference: Williams Gynecology, 3rd ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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