Childhood-onset schizophrenia and tryptophan hydroxylase gene polymorphism.

We explored the relationship between the tryptophan hydroxylase gene polymorphism and susceptibility to childhood-onset schizophrenia in a Japanese sample. Subjects were 51 Japanese patients who met DSM-IV criteria for schizophrenia before age 16 and 148 Japanese healthy controls. DNA was extracted from whole blood and genotyping was performed by PCR-RFLP using Nhe I.

Early-onset schizophrenia and dopamine-related gene polymorphism.

Schizophrenic patients with an onset before age 16 years (early-onset schizophrenia, EOS) would be a rare but attractive subpopulation for genetic studies. This study explored the relationship between the polymorphism of four dopamine-regulating-enzymes (tyrosine hydroxylase, dopamine-beta-hydroxylase, catechol-O-methyltransferase, monoamine oxidase-A) genes, four dopamine-receptors (dopamine D1, D2, D3, D4 receptors) genes and susceptibility to EOS in a Japanese sample. Subjects comprised 51 Japanese patients who met DSM-IV criteria for schizophrenia with an onset before age 16 (by age 15) and 148 Japanese healthy controls.