RESUMO
Numerous studies have evaluated the association between the CYP11B2 gene -344T>C polymorphism and coronary artery disease (CAD) risk. However, the specific association is still controversial. To address this issue, PubMed, EMBASE, and China National Knowledge Infrastructure databases were searched for eligible articles that reported on the relationship between the CYP11B2 gene -344T>C polymorphism and CAD, and were published before April 2014. Data from five separate studies with 3687 subjects were analyzed by meta-analysis. No significant variation in CAD risk was detected by any of the genetic models in the overall study population. Taking into account the effect of ethnicity, further stratified analyses demonstrated significant association in both Caucasian (TT vs TC: OR = 0.80, 95%CI = 0.64-1.00) and Asian populations (TT vs TC: OR = 1.25, 95%CI = 1.01-1.54; dominant model: OR = 0.80, 95%CI = 0.66-0.98). The pooled ORs were not substantially altered after the exclusion of one study in the control group that deviated from Hardy-Weinberg equilibrium, highlighting the reliability of our meta-analysis results. In conclusion, this meta-analysis suggested that the -344T>C polymorphism in the CYP11B2 gene might be associated with susceptibility to CAD in Caucasians and Asians.
Assuntos
Doença da Artéria Coronariana/genética , Citocromo P-450 CYP11B2/genética , Predisposição Genética para Doença/genética , Polimorfismo de Nucleotídeo Único , Povo Asiático/genética , Doença da Artéria Coronariana/etnologia , Frequência do Gene , Predisposição Genética para Doença/etnologia , Genótipo , Humanos , Razão de Chances , Fatores de Risco , População Branca/genéticaRESUMO
Insulin-like growth factor II (IGF-II) plays a key role in mammalian growth and is involved in stimulating fetal cell division, differentiation, and metabolic regulation. IGF-II is considered a candidate gene for genetic markers of growth and carcass traits. Therefore, in this study, the associations of single nucleotide polymorphisms (SNPs) in the IGF-II gene region with growth and carcass characteristics in five yak breeds were investigated. Two SNPs, G(330)C and A(358)G, were identified by sequencing intron 8 of the IGF-II gene in homozygotes. Two alleles, A and B, and three genotypes, AA, AB, and BB, were identified by polymerase chain reaction. Genotypic frequencies of IGF-II allele B were 0.8623, 0.8936, 0.8535, 0.8676, and 0.8300 for Datong yak, Gannan yak, Tianzhu white yak, Qinghai Plateau yak, and Xinjiang yak, respectively. Allele and the genotype of IGF-II were strongly associated with growth and carcass traits. Least square analysis revealed a significant effect (P < 0.01) of genotypes AA and AB compared with genotype BB on live-weight (at 12, 13-24, and 25-36 months of age), average daily weight gain (P < 0.01) and carcass weight (P < 0.05). Animals with genotype AB had a higher mean rib eye area, and a lower mean yield grade. The results indicated that the IGF-II gene acts by a primarily additive biological mechanism by adding weight independently of skeletal growth.