What role does TCF7L2 play in Langlebigkeit?

TCF7L2 is a transcription factor central to Wnt signaling and glucose homeostasis. Certain variants (e.g., rs7903146) are the strongest known genetic risk factors for type 2 diabetes (T2D). Since T2D substantially reduces life expectancy, TCF7L2 can indirectly affect longevity. However, direct associations with longevity are not robustly established; evidence comes from GWAS on T2D, not longevity cohorts. Effect sizes are moderate, and lifestyle factors dominate. A MyBody-X DNA test can report risk variants but cannot diagnose disease. Caveat: predictive value is ancestry-dependent and not deterministic for individual lifespan.