A Genome-wide Association Case Study on Obesity
Overweight and obesity are receiving widespread attention with global projections of more than 2.16 billion overweight and 1.12 billion obese individuals by 2030. The impact of environmental factors (i.e., food intake and energy expenditure) on obesity is significant but still poorly understood and it is clear that the condition has an equally noteworthy underlying genetic component. Twin studies have indicated heritability estimates of ∼70% for body mass index (BMI), both in children and adults and other measures of obesity (skinfold thickness, waist circumference, total fat mass and regional fat distribution) show similar values. There are differences among ethnic and racial groups in obesity and recent efforts in admixture mapping have demonstrated that obesity correlates closely with the percentage of ancestry deriving from ethnic groups with elevated prevalence of obesity. Dissection of the genetic etiology of obesity is pursued with the hope of unraveling pathways and mechanisms that control obesity that in turn would lead to better prevention, management and therapy.