Glutaric aciduria type-1 in a teenager with nutritional vitamin B12 deficiency: coexistence of two treatable conditions.

Nutritional deficiency-associated morbidity is still widespread in India and occurs due to various factors like lifestyle, diet and social and cultural issues. Here, we report a teenager who presented with symptoms and signs of vitamin B12 deficiency in association with a rare underlying metabolic disorder. A teenager in his early adolescence presented with acute febrile illness with clinical signs of hypopigmented hair, knuckle hyperpigmentation, dystonia and spasticity. Neuroimaging showed bilateral putamen signal changes and batwing sign features with a deranged metabolic profile (elevated serum homocysteine with low serum vitamin B12, free carnitine and acylcarnitine). Further, exome sequencing identified a novel, likely pathogenic frameshift deletion, c.1021delA, with the change of amino acid from threonine to leucine at position 341 with the introduction of stop codon after 16 amino acids with subsequent protein truncation, in the GCDH gene. Thus, we started the patient on parental cobalamin therapy with a glutaric aciduria type-1 specific diet. On follow-up, the child showed significant improvement, with a decrease in hyperpigmentation and dystonia.