Biotin-Responsive Basal Ganglia Disease: Treatable Metabolic Disorder with SLC19A3 Mutation Presenting as Rapidly Progressive Dementia

Background and Aims: Biotin-thiamine-responsive basal ganglia disease (BTBGD) is an autosomal recessive disorder due to mutations in the SLC19A3-gene, typically seen in early childhood. Materials and Methods: We report a 49-year-old lady presenting with rapidly progressive cognitive impairment, seizures, hypersomnolence, ataxia, and generalized dystonia of 3 weeks duration. The magnetic resonance imaging (MRI) of the brain revealed T2-hyperintensities in the basal ganglia, thalamus, cortical, subcortical regions with striatal necrosis suggestive of BTBGD that was confirmed by genetic analysis. She was treated with thiamine and biotin following which there was significant clinical and MRI improvement. Conclusions: BTBGD requires a high index of suspicion in any patient presenting with unexplained rapidly progressive dementia. High doses of biotin and thiamine are the mainstay of the treatment to achieve a favorable outcome.