A 16-year-old girl presents with primary amenorrhea. She is 142 cm tall, has a webbed neck, widely spaced nipples, and a shield chest. Cardiac echocardiography reveals bicuspid aortic valve. What is the most likely karyotype?

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

Explanation

Turner syndrome (45,X) is characterized by short stature, webbed neck, widely spaced nipples, shield chest, primary amenorrhea, and cardiovascular anomalies including bicuspid aortic valve and coarctation of the aorta. The diagnosis is confirmed by karyotype showing complete or partial absence of one X chromosome. 46,XY indicates complete androgen insensitivity. 47,XXY is Klinefelter syndrome in males. Xp deletion is a variant of Turner but 45,X is the classic and most common karyotype. (Robbins Pathologic Basis of Disease; Nelson Textbook of Pediatrics).

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.