Caffeine (1, 3, 7-trimethylxanthine) is the most widely consumed psychoactive drug in the world. It has antioxidant and insecticide properties that can affect metabolism and cognition. Men and women aged 35 to 64 years are among the highest consumers of caffeine. Major sources of caffeine were coffee (71%), soft drinks (16%), and tea (12%). Coffee was the major source of caffeine in the diets of adults, whereas soft drinks were the primary source for children and teens [2]. Although social and demographic parameters are associated with regular consumption of caffeine beverages and drinks, studies report a large heritable component. Fig: Structure of Caffeine (Source: Wikipedia)
Studies shows heritability estimates between 0.36 – 0.58 for …show more content…
Calculated Genomic inflation factor (λ) were ranging from 1.00 to 1.03, suggesting population stratification was well controlled. ‘λ’ is defined as the ratio of the median of the empirically observed distribution of the test statistic to the expected median, thus quantifying the extent of the bulk inflation and the excess false positive rate [6] . Population stratification can be eliminated if random mating is done over tens of generation between groups of great physical separation. Thus controlled population stratification is good when a group study is done because as physical distance increases, genetic drift of allele frequencies increases which affect the loci in random manner [7]. 2.5 million SNP’s per group are generated and parsed according to some criterion. A total of 433,781 imputed and genotyped SNPs (Single Nucleotide Polymorphism) were selected for meta-analysis. Two-strong associated SNP’s were found in the