X-linked Dystonia-Parkinsonism manifesting in a female patient due to atypical turner syndrome

ABSTRACT Background Recessive X‐linked dystonia‐parkinsonism almost exclusively affects men. We investigated the genetic mechanisms causing this disorder in a female patient. Methods We confirmed the presence of an X‐linked dystonia‐parkinsonism–specific change in our patient by sequencing. In addition, we employed quantitative real‐time PCR and array comparative genomic hybridization to determine the patient's X‐chromosome copy number. Results The patient's sequence electropherogram suggested a higher amount of the mutated allele compared with the wild‐type allele. Subsequently, extensive gene dosage analyses revealed a copy number of the X chromosomes between 1 and 2, indicating loss of 1 X chromosome in a subset of cells. Phenotypic reevaluation of the patient showed several clinical features of Turner syndrome. Conclusions Our female X‐linked dystonia‐parkinsonism patient suffered from an undiagnosed X‐chromosome monosomy in a subset of cells (45,X/46,XX), suggesting an atypical Turner syndrome and contributing the first molecular explanation for the manifestation of an X‐linked dystonia‐parkinsonism phenotype in women. © 2013 Movement Disorder Society