23 research outputs found
Microglia in the dorsal raphe nucleus plays a potential role in both suicide facilitation and prevention in affective disorders
Elevated expression of tryptophan hydroxylase-2 mRNA at the neuronal level in the dorsal and median raphe nuclei of depressed suicides
Associations between polymorphic variants of the tryptophan hydroxylase 2 gene and obsessive-compulsive disorder Associação entre polimorfismos do gene da triptofano hidroxilase 2 e o transtorno obsessivo-compulsivo
OBJECTIVE: A substantial body of evidence suggests that obsessive-compulsive disorder has a genetic component, and substantial candidate genes for the disorder have been investigated through association analyses. A particular emphasis has been placed on genes related to the serotonergic system, which is likely to play an important role in the pathogenesis of obsessive-compulsive disorder. The gene for tryptophan hydroxylase 2, which is a rate limiting enzyme in serotonin synthesis is considered an important candidate gene associated with psychiatric disorders. METHOD: Our sample consisted of 321 subjects (107 diagnosed with obsessive-compulsive disorder and 214 healthy controls), which were genotyped for eight tagSNPs (rs4448731, rs4565946, rs11179000, rs7955501, rs10506645, rs4760820, rs1487275 and rs10879357) covering the entire human tryptophan hydroxylase 2 gene. Statistical analyses were performed using UNPHASED, version 3.0.12, and Haploview ((R)). RESULTS: Single markers, genotype analysis did not show a significant genetic association with obsessive-compulsive disorder. A significant association between the T-C-T (rs4448731, rs4565946, rs10506645) and C-A-T (rs4565946, rs7955501, rs10506645) haplotypes and obsessive-compulsive disorder was observed, as well as a strong linkage disequilibrium between SNPs rs4448731 and rs4565946, and SNPs rs10506645 and 4760820. DISCUSSION: Our research has not demonstrated the existence of associations between the eight SNPs of TPH2 and obsessive-compulsive disorder. However, two LD and two haplotypes areas were demonstrated, thus suggesting that more studies in TPH2 are needed to investigate the role of tryptophan hydroxylase 2 variants in obsessive-compulsive disorder.<br>OBJETIVO: Diversos estudos demonstram que o transtorno obsessivo-compulsivo apresenta considerável contribuição genética, com diversos genes candidatos tendo sido estudados por meio de estudos de associação. Como alterações do sistema serotonérgico estão associadas ao transtorno obsessivo-compulsivo, o gene da triptofano hidroxilase 2, enzima limitante da síntese da serotonina, é plausível candidato para estudos. MÉTODO: Nossa amostra é composta de 321 sujeitos (107 pacientes com transtorno obsessivo-compulsivo e 214 controles) e investigamos oito tagSNPs (rs4448731, rs4565946, rs11179000, rs7955501, rs10506645, rs4760820, rs1487275 e rs10879357) do gene da triptofano hidroxilase 2. Análise estatística foi realizada com os programas UNPHASED e Haploview. RESULTADOS: Análise de frequência alélica e genotípica entre casos e controles não evidenciaram diferenças estatisticamente significativas. No entanto, observamos maior prevalência dos haplótiposT-C-T (rs4448731, rs4565946, rs10506645) e C-A-T (rs4565946, rs7955501, rs10506645) entre os pacientes, assim como duas regiões com importantes desequilíbrios de ligação (SNPs rs4448731 e rs4565946; SNPs rs10506645 e 4760820). DISCUSSÃO: Nossos achados não demonstraram uma associação entre os SNPs do gene da TPH2 e o transtorno obsessivo-compulsivo, porém mais estudos são necessários, já que fortes desequilíbrios de ligação foram demonstrados, assim como dois haplótipos