Background: Biotin-thiamine-responsive basal ganglion (BTBGD) is an autosomal recessive neuro metabolic disorder associated with pathogenic variants in SLC19A3 gene. Theclinical presentation includessubacute encephalopathy (e.g., Confusion, dysphagia, dysarthria,and seizures), which respond very well to early treatment with thiamine and biotin. In our case,patient presented with acute encephalopathy, ataxia, dystonia, dysarthria later quadriparesis.The baseline MRI Brain demonstrated abnormal signal intensity in cerebral cortex both in supraand infratentorial areas and basal ganglion. Once diagnosis of biotin-thiamine-responsive basalganglion was made, patient was started on high doses of oral thiamine and biotin. GeneticTesting demonstrated pathogenic variant in SLC19A3 gene. After start of treatment with oralbiotin and thiamine patient started improvement in clinical course within days. Afterimprovement patient was discharged home and advised to follow up in pediatric neurologyclinic. In follow up patient showed both clinical and radiological improvement. Family screeninwas done showed both parents are carriers and one sister has similar mutation but all of themwere asymptomatic.

Conclusion: BTBGD is an extremely rare inherited condition and achallenging diagnosis to make due tononspecific clinical presentation of encephalopathy andseizures. Early treatment and diagnosis affect the outcome of disease.