RESUMO
BACKGROUND: A number of studies have pointed to the involvement of AKT signaling pathways in the etiology of schizophrenia. The purpose of this study was to determine whether the AKT1 gene is involved in the etiology of schizophrenia and whether it affects therapeutic outcomes in the Chinese population. METHOD: Five single nucleotide polymorphisms (SNPs) were genotyped among 384 schizophrenic patients (DSM-IV criteria) and 384 healthy controls from the Chinese population. We systematically analyzed the association of the AKT1 gene with schizophrenia on the basis of sex, age at onset, therapeutic response to typical antipsychotics and atypical antipsychotics, and presence or absence of extrapyramidal syndrome. The study was conducted from May 2004 to June 2006. RESULTS: We found a positive association of the G allele of the SNP marker rs3803300 with schizophrenia (p = .003), both in early-onset and late-onset subjects, and that a haplotype A-G-C-G-A constructed by the 5 SNPs showed significant association (p = .00004886). However, we found no relationship between any of the 5 SNP markers and therapeutic response to typical and atypical antipsychotics and chlorpromazine-induced extrapyramidal syndrome. CONCLUSIONS: Our study suggests that AKT1 is a susceptibility gene for schizophrenia in the Chinese population and that the AKT1 gene may play no major role in the therapeutic response to antipsychotics or in chlorpromazine-induced extrapyramidal syndrome.
Assuntos
Antipsicóticos/uso terapêutico , Povo Asiático/genética , Clorpromazina/uso terapêutico , Expressão Gênica/genética , Polimorfismo Genético/genética , Proteínas Proto-Oncogênicas c-akt/genética , Esquizofrenia , Adulto , Idade de Início , Antipsicóticos/efeitos adversos , Doenças dos Gânglios da Base/induzido quimicamente , Doenças dos Gânglios da Base/etnologia , China , Clorpromazina/efeitos adversos , Cromossomos Humanos Par 14/genética , Primers do DNA/genética , Feminino , Frequência do Gene , Genótipo , Haplótipos/genética , Humanos , Masculino , Plasticidade Neuronal/fisiologia , Esquizofrenia/tratamento farmacológico , Esquizofrenia/etnologia , Esquizofrenia/genética , Transdução de Sinais/genéticaRESUMO
Genetic variants in the 22q11 gene ZDHHC8, which encodes a putative transmembrane palmitoyltransferase, has been associated to schizophrenia in family-based linkage disequilibrium (LD) studies. The single nucleotide polymorphism (SNP) rs175174 (A/G), which had the strongest association, has been shown recently to regulate the level of the fully functional transcript by modulating the retention of intron 4 of ZDHHC8. In this work, we genotyped three genetic variants within the ZDHHC8 locus and conducted association studies in both population- and family-based samples of the Han Chinese population. The three polymorphisms spanning approximately 5.5 Kb were detected to be in significant LD. Our results provided compelling supportive evidence for association of the variants within the ZDHHC8 locus with schizophrenia but revealed different risk allele at SNP rs175174. The G allele was significantly more common in cases than in controls (69.47 : 59.96%; P=0.000018) and excess transmission of the same allele was confirmed in the family-based transmission disequilibrium test (transmitted/non-transmitted=87 : 54; P=0.0055). Both sample sets even shared the same risk haplotype with similar frequency. Our current data presents consistent association results obtained from both case-control and family-based samples in a same laboratory under the same experimental condition. Despite the potential genetic heterogeneity, our independent findings further support that the 22q11 region is likely to harbor candidate schizophrenia susceptibility genes.