Aphonia in Infantile Tremor Syndrome

Excerpt

To the Editor: A 9-mo-old girl presented with regression of milestones for 2 mo. She had lost her ability to vocalize, and had a silent cry for 2 wk. She was exclusively breastfed by a vegetarian mother. On examination, she had pallor, sparse thin depigmented hairs, and hyperpigmentation over dorsum of hands and feet. Her serum vitamin B12 (200 mmol/L) was low and plasma homocysteine (24 pg/ml) was elevated; blood thiamine levels were normal (0.44 µg/dl). She was treated with intramuscular Hydroxycobalamin 1 mg per day. On day 3 of treatment, she developed tremors, and on day 7, started to regain her cry. At follow-up 6 mo later, she had gained milestones, and her voice was normal. …