Omnigenic not single SNPs
A premise of precision medicine and nutrition is that genetic information can be used to target medicines and foods for individuals to improve health. The common variant-common disease model was the conceptual basis for genome wide association studies that have identified 138,312 variants (of a total of ~320 million in humans) associated one or more complex traits. While the genetic community generally acknowledges that multiple loci contribute to conditions, additive polygenic risk scores have not proved useful for determining treatments or nutritional interventions.
A new omnigenic model (https://tinyurl.com/yxd2qnlk) posits that a small set of core genes directly affect conditions or traits (albeit with small effect sizes). A larger number of peripheral genes in this model function in cell specific networks that indirectly affect the phenotype. Members of the peripheral gene family could include regulatory molecules that alter the expression of core genes as well as non-core genes. Although controversial (e.g., https://tinyurl.com/y4obpn5d), this model can be tested.
Genetic models are important not only to guide research but also the development of diagnostics and treatment options for personalized healthcare.