title: Association analysis of the tryptophan hydroxylase 2 gene polymorphisms in patients with methamphetamine dependence/psychosis.
abstract: There is a growing evidence that serotoninergic systems modulate dopaminergic neurotransmission. We analyzed the association between the variations in the brain tryptophan hydroxylase 2 (TPH2) gene, a rate limiting enzyme for serotonin biosynthesis, and methamphetamine (METH) dependence/psychosis in a Japanese population. We found ten single nucleotide polymorphisms (SNPs) and two polynucleotide polymorphisms in TPH2 gene exons and exon-intron boundaries. A total of 162 patients and 243 controls were used for the association analysis between these polymorphisms and METH dependence/psychosis. No significant differences were observed in either genotypic or allelic frequencies between METH dependent/psychotic patients and controls. A global test of differentiation among samples based on haplotype frequencies showed no significant association. With respect to latency of psychosis, prognosis of psychosis, and spontaneous relapse, we found no significant association with these SNPs. These results suggest that the TPH2 gene variants may not be a factor in vulnerability to METH dependence/psychosis.
authors: Department of Biological Psychiatry, Tohoku University Graduate School of Medicine, Sendai 980-8574, Japan.
authors: Hideaki
authors: H
authors: Kobayashi
authors: Hiroshi
authors: H
authors: Ujike
authors: Nakao
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authors: Iwata
authors: Toshiya
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authors: Inada
authors: Mitsuhiko
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authors: Yamada
authors: Yoshimoto
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authors: Sekine
authors: Naohisa
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authors: Uchimura
authors: Masaomi
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authors: Iyo
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authors: Ozaki
authors: Masanari
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authors: Itokawa
authors: Ichiro
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authors: Sora