A Novel DYT-5 Mutation with Phenotypic Variability within a Colombian Family

BACKGROUND: DYT-5 dystonia usually presents as a dopa-responsive dystonia (DRD) with early or late parkinsonian manifestations and/or dystonic features. Genetically, these patients have been described as having a wide array of independent mutations in the guanosine triphosphate cyclohydrolase 1 gene (GCH1), and these patients may also have a wide array of clinical manifestations. METHODS: A Colombian family with six affected female members was characterized. RESULTS: Three members, including the index case, revealed mild parkinsonism, whereas three granddaughters of the index case showed severe generalized dystonia. No men were affected. There was anticipation, and a female predominance was uncovered. Treatment with levodopa was generally effective except in a case with severe skeletal deformities and contractions. Detailed genetic analysis in the index case revealed a new mutation in exon 1 of GCH1 (c.159delG). DISCUSSION: This study revealed a new mutation of GCH1 that resulted in heterogeneous clinical presentations of DRD within a large family.