gene frequency human 77 Article 60 Humans 56 female 55 male 53 controlled study 52 genetics 49 adult 47 single nucleotide polymorphism 45 genotype 42 Female 38 Male 38 major clinical study 37 genetic association 31 Gene Frequency 28 Polymorphism, Single Nucleotide 28 genetic variability 28 middle aged 28 Middle Aged 27 allele 27 article 25 Genetic Predisposition to Disease 23 genetic predisposition 22 Adult 21 aged 21 case control study 21 gene 20 Aged 18 Case-Control Studies 17