Genetic Effects on Longitudinal Changes in Risk Factors for Chronic Disease: the San Antonio Family Heart Study.

Here is the abstract for some research I'm presenting at the Human Biology Association Meeting next week. The title is above and the abstract below.

There is considerable interest among human geneticists in the localization of quantitative trait loci (QTLs) that contribute to chronic disease. However, QTLs are commonly analyzed from a single time point although evidence exists that their associated phenotypes change over the lifespan. Therefore, identifying QTLs that contribute to longitudinal changes in these traits may provide a more complete understanding of biological pathways and of variation in rate of phenotypic change with age. This study examined heritability of phenotypic differences in 24 anthropometric and biochemical variables associated with cardiovascular disease in participants from the San Antonio Family Heart Study. Individuals were measured in three exams over 15 years and all examined variables had shown an associated significant QTL (LOD >3) during at least one of these exams. Three variables representing longitudinal change: absolute difference between exams, percent difference from baseline exam, and the slope of a line fitted to the three time points. Longitudinal change variables showing significant heritability (p < 0.05 ) >0.35 and were subjected to genome-wide linkage analysis. Significant bivariate linkage (LOD =3.13) was only detected for ICAM-1 and its phenotypic difference on chromosome 7q21. This ICAM-1 linkage differs from its originally identified QTL on chromosome 19p and indicates that the phenotypic rate of change of this trait may be influenced by unidentified genes on chromosome 7q21.