Fig. 1: Conceptual illustration of genetic variant association with eGFR over time/age and phenotypic models. | Nature Communications

Fig. 1: Conceptual illustration of genetic variant association with eGFR over time/age and phenotypic models.

From: Analyzing longitudinal trait trajectories using GWAS identifies genetic variants for kidney function decline

Fig. 1

a Genetic variant (SNP) associations with eGFR can arise through one allele (risk allele A) that accelerates eGFR-decline over time/age (left) or lowers eGFR in a constant fashion over time/age (right) as compared to the other allele (a). This suggests that genetic variants associated with eGFR-decline are found among genetic variants associated with eGFR cross-sectionally. Shown is a schematic for persons with A/a versus a/a. b Temporal change of eGFR can be modeled in longitudinal data in various ways (phenotypic models): as (i) difference between last and 1st eGFR value of a person (difference model; assessments in-between 1st and last unused and thus depicted as circles); (ii) eGFR over time via linear mixed model (LMM) with person-specific intercepts and slopes (LMM time model RI&RS; time = 0 corresponds to an individual’s 1st eGFR assessment); (iii) eGFR over age (LMM age model RI&RS); or (iv) eGFR over age without random slopes (LMM age model RI-only; time model RI-only possible, but not applied/shown). Shown is a schematic of the phenotypic modeling for two example persons.

Back to article page