A 9-month-old breastfed infant from a strictly vegetarian family presents with pallor, irritability, poor feeding, and regression of motor milestones. Blood smear shows macrocytic anaemia. Serum B12 is 88 pg/mL (normal >200). Which feature would be MOST characteristic on neurological examination?
- A Peripheral neuropathy with loss of vibration sense
- B Infantile tremor syndrome with apathy, pigmentation changes, and movement arrest ✓
- C Subacute combined degeneration of the spinal cord with spasticity
- D Optic atrophy and cortical blindness
Explanation
Infantile B12 (cobalamin) deficiency in exclusively breastfed infants of vegetarian/vegan mothers presents with the 'Infantile Tremor Syndrome' — a classic Indian pediatric presentation characterised by hyperpigmentation, regression of developmental milestones, involuntary movements (tremors), apathy/irritability, hypotonia, and movement arrest. Megaloblastic anaemia is present. Serum B12 is low; plasma homocysteine is elevated. Subacute combined degeneration occurs in older patients and adults with chronic B12 deficiency. Peripheral neuropathy is also seen but tremor syndrome is the hallmark in Indian infants. Treatment with IM cyanocobalamin/hydroxycobalamin results in dramatic neurological recovery.
Reference: Ghai Essential Pediatrics, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.