A 17-year-old girl presents with primary amenorrhea, normal female phenotype, blind-ending vagina (vaginal length 5 cm), absent uterus, and normal female range testosterone. Karyotype is 46,XX. The MOST likely diagnosis is:

• A Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome ✓
• B Complete androgen insensitivity syndrome (CAIS)
• C Transverse vaginal septum
• D Imperforate hymen

Explanation

MRKH syndrome (Müllerian aplasia) presents with 46,XX karyotype, female phenotype, absent or rudimentary uterus and upper vagina (but normally functioning ovaries, hence normal female testosterone), and primary amenorrhea. CAIS has 46,XY karyotype with testosterone in the male range (falsely 'normal female' on some labs — distinguish by karyotype). Transverse vaginal septum and imperforate hymen cause haematocolpos with cyclic pain rather than complete primary amenorrhea without cramps, and the uterus is present.

Reference: Shaw's Textbook of Gynaecology, 17th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.