An infant has dystopia canthorum, a white forelock, heterochromia iridis, and sensorineural deafness. Genetic testing shows a mutation affecting a transcription factor required for survival and migration of melanocyte-lineage neural crest cells. Mutations in which gene best fit this presentation?
- A PAX1
- B OLIG2
- C SOX10 ✓
- D EN1
Correct answer: C. SOX10
Explanation
Waardenburg syndrome type 4 (Shah-Waardenburg) combines pigmentary disturbances, deafness and Hirschsprung disease, and results from SOX10 mutations. SOX10 sustains neural crest cells migrating along both the melanocyte pathway and the enteric neuroblast pathway. OLIG2 specifies motor neuron progenitors, PAX1 marks sclerotome-derived vertebral bodies, and EN1 patterns the midbrain-hindbrain junction, so none explains pigmentary and enteric defects together.
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.