Abstract
Biotin-thiamine responsive basal ganglia disease (BTRBGD) is an autosomal recessive
neurometabolic disorder with poor genotype-phenotype correlation, caused by mutations
in the SLC19A3 gene on chromosome 2q36.6. The disease is characterized by three stages: stage 1
is a sub-acute encephalopathy often triggered by febrile illness; stage 2 is an acute
encephalopathy with seizures, loss of motor function, developmental regression, dystonia,
external ophthalmoplegia, dysphagia, and dysarthria; stage 3 is represented by chronic
or slowly progressive encephalopathy. Clinical and biochemical findings, as well as
the magnetic resonance imaging (MRI) pattern, resemble those of Leigh's syndrome,
so that BTRBGD can be misdiagnosed as a mitochondrial encephalopathy.Here we report
the clinical and radiological phenotypes of two siblings diagnosed with BTRBGD in
which a novel SLC19A3 mutation (NM_025243.3: c.548C > T; p.Ala183Val) was found by whole exome sequencing
(WES) of the family members.
Keywords
biotin-thiamine responsive basal ganglia disease - biotin - thiamine - encephalopathy
- Leigh's syndrome