Today’s spotlight on Dystonia is…
Dopa-responsive dystonia (DRD)
DRD is a general term for a few disorders in which generalized dystonia and Parkinsonism are present and often dramatically respond to treatment with levodopa. Levodopa is an amino acid that is converted to dopamine. Dopamine is a brain chemical that serves as a neurotransmitter and is deficient in individuals with DRD. Affected individuals may be misdiagnosed as having cerebral palsy or Parkinson’s disease.
Two main forms have been identified and are known as Segawa syndrome, due to mutations of the GTP cyclohydrolase 1 (GCH1) gene (called DYT/PARK-GCH1), and tyrosine hydroxylase (TH) deficiency (called DYT/PARK-TH), although many other disorders may mimic dopa-responsive dystonia, including juvenile Parkinsonism. Segawa syndrome is inherited in an autosomal dominant manner; tyrosine hydroxylase deficiency is inherited in an autosomal recessive manner. NORD has individual reports on both of these disorders. These disorders are also known as DYT5A and DYT5B. Recessive forms of dopa-responsive dystonia can be caused also by sepiapterin reductase (SPR) deficiency.
More information on Dopa-Responsive Dystonia can be found from Dystonia Medical Research Foundation Canada