关键词: Segawa病；　多巴胺；　肌张力障碍；　TH基因

Abstract: Objective　To explore the clinical and genetic characteristics, treatment。 and prognosis of dopamine responsive dystonia (DRD) in children. Method　The clinical data of DRD in 3 children admitted to neurology clinic from January 2014 to August 2017 were retrospectively analyzed. Results　Two male children, 20-month-old and 2-year-old respectively, and one 4-year-old female child suffered from hypotonia after birth or one year after birth. Genetic testing found that case 1 had heterozygous mutations in tyrosine hydroxylase (TH) gene, C. G943A (p. G315S) from his mother (PMID 20056467) and C. G739A (p. G247S) from his father (PMID 18554280, 24753243). Case 2 had a heterozygous mutation, c.454-2A>G, in GCH-1 gene, which was identified to be from his father (PMID 10732814). Case 3 had two mutations in TH1 gene, c.580+2T>C from her mother (novel mutation) and c.698G>A (p.R233H) from her father (PMID 9703425). The mother of case 1 was pregnant again. Prenatal examination revealed that the fetus only carried c.G943A (p.G315S) from the mother. Three patients were treated with a small dose of madopar after diagnosis, and gradually increased to obtain the best effect. After 6-month follow-up, cases 1 and 2 recovered to normal, and case 3 showed significant improvement in dystonia, but left foot deformity. Conclusion　DRD can start in infants and young children with atypical early symptoms. Genetic testing can make a definite diagnosis. The family that has proband should undergo prenatal examination.

Key words: dopamine;　dystonia;　TH gene