Can a consumer DNA test interpret FUT2 reliably?

Yes, a consumer DNA test can reliably genotype common FUT2 variants (e.g., rs601338) with high accuracy (>99% for established SNP arrays). The interpretation of secretor status is straightforward for these common variants. However, reliability decreases for rare or untyped variants, which may lead to incomplete or incorrect classification. Furthermore, the clinical utility is limited: secretor status influences susceptibility to norovirus and some bacterial infections, but no evidence-based lifestyle or medical actions are universally recommended. The evidence for genotyping accuracy is strong (human validation studies), while the health implications are supported by observational data (moderate). Consumer tests are not diagnostic and should not replace medical advice. In summary, interpretation is reliable for common FUT2 variants, but the practical health impact is modest and context-dependent.