Biotin Thiamin Responsive Basal Ganglia Disease in Siblings

Biotin Thiamine responsive Basal Ganglia Disease (BTBGD) is a rare treatable autosomal recessive metabolic disorder caused by mutations in SLC19A3 gene. It usually presents with encephalopathy and dystonia; if not treated, can progress to quadriparesis and death. Two Indian siblings born to a consanguineous marriage presented with regression of milestones, epilepsy and dystonia. Neuroimaging showed signal changes in basal ganglia and thalami. Genetic testing showed a homozygous missense substitution p.Gly23Val (c.68G > T) in exon 2 of the SLC19A3 gene. Thus to conclude, any child who presents with neuroregression, epilepsy and dystonia in the background of basal ganglia changes on neuroimaging, a possibility of biotin thiamine responsive basal ganglia disease should be considered.

Whole exome sequencing reveals compound heterozygous mutations in SLC19A3 causing biotin-thiamine responsive basal ganglia disease

Biotin-thiamine responsive basal ganglia disease (BTBGD) is a rare metabolic condition caused by mutations in the SLC19A3 gene. BTBGD presents with encephalopathy and significant disease progression when not treated with biotin and/or thiamine. We present a patient of Mexican and European ancestry diagnosed with BTBGD found to have compound heterozygous frameshift mutations, one novel. Our report adds to the genotype-phenotype correlation, highlighting the clinical importance of considering SLC19A3 gene defects as part of the differential diagnosis for Leigh syndrome.