Levodopa is effective in the treatment of three Chinese Tyrosine hydroxylase (TH) deficiency children

•TH deficiency is an autosomal recessive inborn error of dopamine transmission, which the deficient gene is at the chromosome 11.•TH deficiency leads to developmental delay, infantile parkinsonism and encephalopathy.•We report three TH deficiency patients. After L-DOPA treatment, their condition had improvement. Tyrosine hydroxylase (TH) deficiency is a rare autosomal recessive inborn error of dopamine transmission, which the deficient gene is at the chromosome 11, also called‘Segawa Syndrome’. TH converts tyrosine into L-DOPA, which is the direct precursor of catecholamine biosynthesis. TH deficiency causes a neurological disease with primary extrapyramidal signs and a variable response to L-DOPA. We report three patients in China who were diagnosed with Tyrosine hydroxylase (TH) deficiency by genetic testing and clinical manifestations. After L-DOPA treatment, their condition had sustained improvement.