Disclosed are methods of identifying elements associated with a trait, such as a disease. The methods can comprise, for example, identifying the association of a relevant element (such as a genetic variant) with a relevant component phenotype (such as a disease symptom) of the trait, wherein the association of the relevant element with the relevant component phenotype identifies the relevant element as an element associated with the trait, wherein the relevant component phenotype is a component phenotype having a threshold value of severity, age of onset, specificity to the trait or disease, or a combination, wherein the relevant element is an element having a threshold value of importance of the element to homeostasis relevant to the trait, intensity of the perturbation of the element, duration of the effect of the element, or a combination. The disclosed methods are based on a model of how elements affect complex diseases. The disclosed model is based on the existence of significant genetic and environmental heterogeneity in complex diseases. Thus, the specific combinations of genetic and environmental elements that cause disease vary widely among the affected individuals in a cohort. The disclosed model is an effective, general experimental design and analysis approach for the identification of causal variants in common, complex diseases by medical sequencing. The disclosed model and the disclosed methods based on the model can be used to generate valuable and useful information.