Is LCT destiny or just a small risk factor?

Is LCT destiny or just a small risk factor? The answer is clear: LCT variants (e.g., rs4988235) are strong predictors of lactase persistence/non-persistence, but not absolute destiny. The C allele (non-persistence) is associated with a very high probability of lactose intolerance in adulthood, with odds ratios >10 in many populations. However, symptoms depend on gut microbiome adaptation, dose, and individual tolerance. Some people with the 'risk' variant can consume small amounts of lactose without issues. Thus, LCT is a major but not deterministic factor. Evidence: human-strong (multiple GWAS and clinical studies). Caveat: a DNA test cannot diagnose lactose intolerance; a hydrogen breath test is the clinical gold standard. Lifestyle and diet can mitigate effects. So LCT is a strong risk factor, not a fixed destiny.