Myths vs facts: FTO and Allergie

FTO (Fat Mass and Obesity-associated) is best known for its strong link to obesity. A common myth is that FTO variants directly cause allergies. The facts: GWAS studies have found weak but reproducible associations between certain FTO SNPs (e.g., rs9939609) and allergic conditions like asthma or atopic dermatitis. However, the effects are small and largely mediated by BMI—FTO influences body weight, and obesity itself increases allergy risk. Direct, obesity-independent mechanisms are not well established. Therefore, DNA testing for FTO variants has no clinical utility for allergy prediction or management. The evidence is primarily GWAS-based, not causal. For allergy assessment, validated methods like specific IgE tests or skin prick tests should be used, not genetic tests. Bottom line: FTO is not an allergy gene; the link is indirect and weak.