Evidence of a quantitative trait locus for energy and macronutrient intakes on chromosome 3q27.3: the Québec Family Study

Background: Little is known about the genes influencing dietary energy and nutrient intakes, despite evidence that these intakes are influenced by genetic factors. Objective: We aimed to identify, by using a genome-wide linkage analysis, chromosomal regions harboring genes that affect energy and macronutrient intakes. Design: Energy, carbohydrate, lipid, and protein intakes were assessed in 836 subjects from 217 families by using a 3-d dietary record. A total of 443 markers were genotyped and tested for linkage; age- and sex-adjusted energy and macronutrient intakes were expressed in grams and as percentages of total energy intake. Regression-based (Haseman-Elston) and variance-component (MERLIN) methods were applied to test for linkage with dietary data. A maximum of 454 sibpairs from 217 nuclear families were available for analysis. Results: The genome scan provided suggestive evidence (P ≤ 0.0023) for the presence of 6 quantitative trait linkages influencing total caloric and macronutrient intakes in the Québec Family Study. Of these, multiple linkages were found on chromosome 3q27.3, in a region harboring the adiponectin gene, at marker D3S1262 for energy [logarithm of odds (LOD): 2.24], carbohydrate (LOD: 2.00), and lipid (LOD: 1.65) intakes. The peak linkages for carbohydrate, lipid, and protein intakes were found on chromosomes 1p32.2 (LOD: 2.39), 1p35.2 (LOD: 2.41), and 10p15.3 (LOD: 2.72), respectively. The linkage results remained significant after adjustment for body mass index, which suggested that the genes underlying these quantitative trait linkages influence dietary intake independent of body size. Conclusion: The linkage on chromosome 3q27.3 with energy, lipid, and carbohydrate intakes suggests that this region of the genome may harbor genes that influence energy and macronutrient intakes in humans.