title: A novel missense mutation pattern of the GCH1 gene in dopa-responsive dystonia.
abstract: Dopa-responsive dystonia (DRD) is an inherited metabolic disorder now classified as DYT5 with two different biochemical defects: autosomal dominant GTP cyclohydrolase 1 (GCH1) deficiency or autosomal recessive tyrosine hydroxylase deficiency. We report the case of a 10-years-old girl with progressive generalized dystonia and gait disorder who presented dramatic response to levodopa. The phenylalanine to tyrosine ratio was significantly higher after phenylalanine loading test. This condition had two different heterozygous mutations in the GCH1 gene: the previously reported P23L mutation and a new Q182E mutation. The characteristics of the DRD and the molecular genetic findings are discussed.
authors.affiliation: Neurology Division, Internal Medicine Department, Hospital de Clínicas, Universidade Federal do Paraná, Curitiba, PR, Brazil. scola@hc.ufpr.br
authors.forename: Rosana H
authors.initials: RH
authors.lastname: Scola
authors.forename: Carla
authors.initials: C
authors.lastname: Carducci
authors.forename: Vanise G
authors.initials: VG
authors.lastname: Amaral
authors.forename: Paulo J
authors.initials: PJ
authors.lastname: Lorenzoni
authors.forename: Helio A G
authors.initials: HA
authors.lastname: Teive
authors.forename: Teresa
authors.initials: T
authors.lastname: Giovanniello
authors.forename: Lineu C
authors.initials: LC
authors.lastname: Werneck
mesh_terms: D002648:Child; D015259:Dopamine Agents / Q000627:therapeutic use*; D004421:Dystonia / Q000097:blood / Q000188:drug therapy* / Q000235:genetics*; D005260:Female; D006136:GTP Cyclohydrolase / Q000235:genetics*; D006579:Heterozygote; D006801:Humans; D007980:Levodopa / Q000627:therapeutic use*; D020125:Mutation, Missense / Q000235:genetics*; D010649:Phenylalanine / Q000097:blood; D014443:Tyrosine / Q000097:blood
chemical_list: D015259:Dopamine Agents; D014443:Tyrosine; D007980:Levodopa; D010649:Phenylalanine; D006136:GTP Cyclohydrolase