Neuroregression as an initial manifestation in a toddler with acquired pernicious anaemia.

The aetiology spectrum for neuroregression in infants and toddlers is diverse. Vitamin B12 deficiency-mediated neuroregression is less commonly considered as a differential. Prevalence of pernicious anaemia in the general population is 0.1% and is extremely rare in children. We describe a 35-month-old toddler with neuroregression, seizures, coarse tremors, bleating cry and neuropathy. His clinical symptomatology mimicked grey matter degenerative illness and infantile tremor syndrome, a nutritional deficiency-mediated movement disorder. His vitamin B12 level was low and serum homocysteine level was elevated. Haematological manifestations were not overt and anti-intrinsic factor antibody was positive. With parenteral vitamin B12 therapy, there was a dramatic response with clinical and laboratory translation. This report emphasises the need for a high index of suspicion and screening for markers of vitamin B12 deficiency in all children with unexplained acute or subacute neuroregression, seizures and movement disorders as it is potentially reversible. 2015 BMJ Publishing Group Ltd.