How are FADS1 and Allergie related?

The relationship between FADS1 and allergies stems from the gene's role in polyunsaturated fatty acid metabolism. FADS1 encodes delta-5 desaturase, which converts dihomo-gamma-linolenic acid (DGLA) to arachidonic acid (AA) and eicosapentaenoic acid (EPA) from stearidonic acid. Variants (e.g., rs174546) alter enzyme activity, shifting the AA/EPA ratio. A higher AA/EPA ratio promotes pro-inflammatory eicosanoids, which can exacerbate allergic conditions like asthma, hay fever, and atopic dermatitis. GWAS have linked FADS1 SNPs to total IgE levels and allergic disease risk, but effect sizes are modest. Mechanistic studies support the pathway, but human intervention trials testing genotype-specific dietary modifications (e.g., omega-3 supplementation) are limited. The provided context does not directly address FADS1; this answer draws on general evidence. Consumer DNA tests often overstate the predictive power of single SNPs. Evidence level: human-moderate (GWAS + mechanistic). No specific sources from the given context.