Of note, the prevalence of anemia among males in our cohort was lower than that reported by others [11]. In males, the attainment of adult testosterone concentration is linked to an increase in erythropoiesis [10]; thus, the lower prevalence of anemia among adolescent males can be explained by a physiological increase in Hb concentration secondary to sexual maturation as well as lower Hb demand once the growth spurt has ended [11-12]. Here, GSTM1 is linked to anemia (phenotype).