Study of patients misdiagnosed as Parkinson’s disease in a family with Segawa syndrome and literature review

Objective To analyze the clinical characteristics of Segawa syndrome to strengthen the understanding of Segawa syndrome and its differential diagnosis with Parkinson’s disease. Methods The clinical data of a patient with Segawa syndrome and the family members were retrospectively analyzed. After informed consent, the peripheral blood of the patient and her patients were collected, and DNAs were extracted; high throughput sequencing was used to detect the hereditary movement disorders related genes and Sanger sequencing was performed to verify the results. Results Many patients in this family had onset at adult, mainly presented parkinsonism and dystonia, which was misdiagnosed as having Parkinson’s disease. The proband was child onset and responded favorably to small dose of dopamine, and DNA sequencing showed a mutation of Guanosine triphosphate cyclohydrolase-1 gene, diagnosing as having Segawa syndrome. The same mutation existed in the father of proband and not in her mother. Conclusion It is easy to confuse the adult Segawa syndrome with Parkinson’s disease, and gene detection is an effective differential diagnosis method. Key words: Segawa syndrome; Dopa-responsive dystonia; Parkinson’s disease; Guanosine triphosphate cyclohydrolase 1