What role does FTO play in allergy?

FTO (Fat Mass and Obesity-associated) is primarily known for its role in body weight and fat metabolism. GWAS studies show a small but reproducible effect on BMI (about 0.3 kg/m² per risk allele). A direct, well-established link to allergies does not exist. Some epidemiological studies suggest a possible association with asthma or atopic dermatitis, potentially via immunomodulatory pathways (e.g., FTO influences IRX3/IRX5 expression, which may be involved in inflammatory processes). However, the evidence is weak, inconsistent, and mostly based on observational studies or mechanistic hypotheses. Consumer DNA tests that list FTO variants cannot infer allergy predisposition. Clinically relevant factors such as environment, diet, microbiome, and specific IgE levels dominate. FTO analysis alone is not suitable for allergy prediction or management. Evidence: unclear/mechanistic. Sources: No direct PMIDs in context; general FTO GWAS literature (e.g., Frayling et al., Science 2007).