OBJECTIVES: The aim of this study was to evaluate the association of Val66Met brain-derived neurotrophic factor (BDNF) polymorphism with bipolar disorder in (i) a meta-analysis and (ii) a case-control study in a Mexican population. We also investigated the possible association of this polymorphism with clinical features. METHODS: We performed a keyword search of the PubMed and Web of Science databases. A total of 22 studies that have investigated the association of Val66Met (rs6265) with bipolar disorder were selected for inclusion and combined with random effects meta-analysis, using allelic, additive, dominant, and recessive models. Finally, the single nucleotide polymorphism (rs6265) Val66Met in the BDNF gene was genotyped and compared between 139 patients with bipolar disorder and 141 healthy volunteers in a Mexican population. RESULTS: The pooled results from the meta-analysis (9,349 cases and 7,437 controls) did not show a significant association in any of the models. The same results were obtained in our case-control study when analyzing the distribution of the genotypic frequencies of the Val66Met polymorphism in patients with bipolar disorder. However, when we analyzed the association between rs6265 and lifetime history of suicidal behavior, we found an association between genotype Val-Val and suicide attempt (p = 0.02). CONCLUSIONS: Although the present study has some limitations, the results indicate a lack of association between the Val66Met polymorphism and bipolar disorder. However, in our case-control study in a Mexican population, the Val66Met polymorphism was associated with suicidal behavior in patients with bipolar disorder. Nevertheless, it is important to consider potential interactions of the BDNF gene, the environment, and different inheritance patterns, when carrying out future genetic studies with larger samples.
OBJECTIVES: The aim of this study was to evaluate the association of Val66Met brain-derived neurotrophic factor (BDNF) polymorphism with bipolar disorder in (i) a meta-analysis and (ii) a case-control study in a Mexican population. We also investigated the possible association of this polymorphism with clinical features. METHODS: We performed a keyword search of the PubMed and Web of Science databases. A total of 22 studies that have investigated the association of Val66Met (rs6265) with bipolar disorder were selected for inclusion and combined with random effects meta-analysis, using allelic, additive, dominant, and recessive models. Finally, the single nucleotide polymorphism (rs6265) Val66Met in the BDNF gene was genotyped and compared between 139 patients with bipolar disorder and 141 healthy volunteers in a Mexican population. RESULTS: The pooled results from the meta-analysis (9,349 cases and 7,437 controls) did not show a significant association in any of the models. The same results were obtained in our case-control study when analyzing the distribution of the genotypic frequencies of the Val66Met polymorphism in patients with bipolar disorder. However, when we analyzed the association between rs6265 and lifetime history of suicidal behavior, we found an association between genotype Val-Val and suicide attempt (p = 0.02). CONCLUSIONS: Although the present study has some limitations, the results indicate a lack of association between the Val66Met polymorphism and bipolar disorder. However, in our case-control study in a Mexican population, the Val66Met polymorphism was associated with suicidal behavior in patients with bipolar disorder. Nevertheless, it is important to consider potential interactions of the BDNF gene, the environment, and different inheritance patterns, when carrying out future genetic studies with larger samples.
Authors: Malik Nassan; Paul E Croarkin; Joan L Luby; Marin Veldic; Paramjit T Joshi; Susan L McElroy; Robert M Post; John T Walkup; Kelly Cercy; Jennifer R Geske; Karen D Wagner; Alfredo B Cuellar-Barboza; Leah Casuto; Catharina Lavebratt; Martin Schalling; Peter S Jensen; Joanna M Biernacka; Mark A Frye Journal: Bipolar Disord Date: 2015-09 Impact factor: 6.744
Authors: Yazmín Hernández-Díaz; Carlos Alfonso Tovilla-Zárate; Isela Juárez-Rojop; Manuel Alfonso Baños-González; Manuel Eduardo Torres-Hernández; María Lilia López-Narváez; Teresa Guadalupe Yañez-Rivera; Thelma Beatriz González-Castro Journal: Int J Clin Exp Med Date: 2015-08-15
Authors: Brisa S Fernandes; Marc L Molendijk; Cristiano A Köhler; Jair C Soares; Cláudio Manuel G S Leite; Rodrigo Machado-Vieira; Thamara L Ribeiro; Jéssica C Silva; Paulo M G Sales; João Quevedo; Viola Oertel-Knöchel; Eduard Vieta; Ana González-Pinto; Michael Berk; André F Carvalho Journal: BMC Med Date: 2015-11-30 Impact factor: 8.775