A 14-year-old girl presents with primary amenorrhea. She has Tanner stage 1 breasts, Tanner stage 1 pubic hair, and short stature (height 138 cm, below 3rd centile). FSH is 72 IU/L. Karyotype reveals 45,X/46,XX mosaicism. Which of the following is the most likely clinical feature distinguishing her from classic 45,X Turner syndrome?
- A Higher likelihood of spontaneous puberty and menarche ✓
- B More severe webbing of the neck
- C Greater incidence of coarctation of the aorta
- D More pronounced lymphedema at birth
Correct answer: A. Higher likelihood of spontaneous puberty and menarche
Explanation
Mosaic Turner syndrome (45,X/46,XX) is associated with milder phenotypes compared to classic 45,X. Patients have a higher chance of spontaneous pubertal development (up to 20-30%) and even fertility, though premature ovarian insufficiency is still common. Webbing of the neck, coarctation, and lymphedema are more characteristic of classic 45,X and tend to be less prominent in mosaic forms. Short stature and elevated FSH are still present but the overall phenotype is attenuated.
Reference: Nelson Textbook of Pediatrics, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.