A 15-year-old girl presents with primary amenorrhea, no secondary sexual characteristics (no breast development, no pubic hair), and short stature. FSH is 85 IU/L (elevated), LH 62 IU/L (elevated), estradiol very low. Karyotype shows 46,XX. What is the MOST likely diagnosis?

• A Premature ovarian insufficiency (hypergonadotropic hypogonadism with 46,XX karyotype) ✓
• B Hypogonadotropic hypogonadism (Kallmann syndrome)
• C Androgen insensitivity syndrome (46,XY phenotypic female)
• D Constitutional delay of puberty

Explanation

Elevated gonadotropins (FSH/LH) with low estradiol indicate hypergonadotropic hypogonadism — the pituitary is working hard (high FSH/LH) but the gonads are not responding (low estrogen). With a 46,XX karyotype in a phenotypic female, this is premature ovarian insufficiency (POI)/streak gonads in a chromosomally normal female (can be autoimmune, iatrogenic, or idiopathic). Kallmann syndrome shows LOW gonadotropins (hypogonadotropic). Androgen insensitivity has 46,XY karyotype. Constitutional delay has normal (not elevated) FSH/LH with eventual spontaneous puberty.

Reference: Ghai Essential Pediatrics, 10th ed.

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Written and medically reviewed by the StethoPrep medical team.