Risks and limits of DNA Test Alltag

Consumer DNA tests for everyday use promise deep insights into health, nutrition, or ancestry, but their limitations are substantial. Most tested genetic variants have only small effects on complex traits – a single SNP rarely explains more than 1 % of the variance. For example, rs4988235 (lactase persistence) is well-established, but for metabolic or hormonal questions, clinically relevant associations are often lacking. The MTHFR test is explicitly not recommended by ACMG and CDC because folic acid is metabolized normally even in TT carriers – the 'methylfolate myth' is unsupported by randomized trials. Similarly, markers like LEPR or APOA5 have small effects that are easily overridden by lifestyle. A hormone lab value (e.g., testosterone) is not a DNA test but a snapshot with diurnal variation. Risks include overinterpretation, false reassurance, or unnecessary anxiety. Data privacy and lack of clinical validation for many direct-to-consumer tests are further concerns. Bottom line: DNA tests can spark curiosity but do not replace medical diagnostics. For health-related decisions, consult a physician.