ABSTRACT
Objective To evaluate the clinical features and guanosine triphosphate cyclohydrolase 1 (GCH-1) gene mutation in a family with dopa-responsive dystonia (DRD).Methods The clinical features of this family were collected and their peripheral blood samples were screened for mutation in GCH-1 gene using PCR and DNA direct sequencing.Results The clinical features among each patient in this family were different.But all affected family members had quite a good response to levodopa treatment without significant adverse reactions.DNA test showed an AT deletion mutation at point of 631-632 in the 6th exon of GCH-1 gene in 5 affected members and 1 asymptomatic immediate family member.Conclusions Clinical heterogeneity is an important characteristic of DRD and clinical symptoms vary intra-families.Same gene type may cause different phenotype and not all carriers are patients.The deletion mutation at point of 631-632 in the 6th exon of GCH-1 gene should be considered as a pathogenic mutation for DRD.