Health determinats in a genetic perspective

Identifying the genetic factors that play a role in human health and its maintenance, particularly in the presence of known environmental risk factors, is a fundamental, yet formidable issue. Indeed, this largely involves the analysis of complex traits (quantitative trait loci, QTLs), which is a challenging task, posing special problems that make gene discovery more difficult. The present knowledge on the genes that underlie human health and disease falls broadly into two categories: candidate-gene studies, which use either association or resequencing approaches, and genome-wide studies, which include both linkage mapping and genome-wide association studies. For a more in-depth understanding of health and disease, however, it is increasingly clear that an analysis of gene-environment interactions is required. Physical activity and its biological correlates can be particularly helpful in this respect.