A 2-year-old child presents with pendular nystagmus since 3 months of age. MRI shows thinning of the optic chiasm, absent septum pellucidum, and posterior pituitary ectopia. The most likely diagnosis is:
- A De Morsier syndrome (septo-optic dysplasia) ✓
- B Isolated optic nerve hypoplasia
- C Albinism
- D Achiasma
Correct answer: A. De Morsier syndrome (septo-optic dysplasia)
Explanation
De Morsier syndrome (septo-optic dysplasia) classically presents with the triad of optic nerve hypoplasia, pituitary hormone deficiency (ectopic posterior pituitary on MRI), and midline brain anomalies (absent septum pellucidum, agenesis of corpus callosum). Nystagmus develops early. Isolated ONH lacks the midline brain and pituitary findings. Albinism shows foveal hypoplasia without brain anomalies. Achiasma shows seesaw nystagmus, not pendular.
Reference: Pediatric Ophthalmology and Strabismus, AAO BCSC, 2023-2024 ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.