Biotin Thiamine Responsive Basal Ganglia Disease: Clinical Improvement after Initiation of Biotin and Thiamine Therapy

Background: Biotin thiamine responsive basal ganglia disease is caused by a mutation in SLC19A3. SLC19A3 encodes for the human thiamine transporter 2. Untreated patients show a progressive deterioration with subacute episodes of encephalopathy, dystonia, dysarthria, dysphagia, seizures, and neuroradiographic lesions of the caudate nucleus and putamen.

Case Report: We present two siblings with a homozygous mutation (c.68G>T (p.Gly23Val) in exon 2 of SLC19A3 gene (2q36.3)). Patient 1 showed a normal development until the age of 11 months followed by crisis of loss of motor skills. By the age of 6, the patient presented with a tetraspasticity with rarefied limb movement, dystonia, and lack of interpersonal/social interaction. Cerebral MRI showed a massive, generalized, supra- and infratentorial atrophia. Patient 2 developed normally until the age of 10 months, followed by distinct regression with dystonia and poor feeding. At the age of 14 months, an acute deterioration with encephalopathic behavior, reduced social interaction, lack of head control, and severe nutritional problems occurred. Bilateral lesions of gray matter, caudate nucleus, and putamen were all present in cerebral MRI. In Patient 2, after initiation of high-dose biotin and thiamine, we observed a clinical stabilization and gradual improvement. Patient 1 showed no improvements and due to intolerance, the medication was stopped after a few weeks.

Conclusion: In an acute/subacute presentation of encephalopathy combined with suggestive MRI, a medication with biotin and thiamine should be considered.

Keywords: SLC19A3 mutation, biotin thiamin responsive basal ganglia disease