A Genome Scan for Linkage With Aortic Root Diameter in Hypertensive African Americans and Whites in the Hypertension Genetic Epidemiology Network (HyperGEN) Study

Background Aortic root dilation is a prominent feature in several cardiovascular diseases. This study seeks to identify genomic regions linked to variation in the aortic root diameter (ARD) in hypertensive African American and white individuals. Methods We performed a genome scan for ARD in the Hypertension Genetic Epidemiology Network Study, one of four networks in the National Heart, Lung, and Blood Institute Family Blood Pressure Program (FBPP). Data were collected from 1129 African American siblings from 504 hypertensive sibships and 883 white siblings from 374 hypertensive sibships. Standardized residual values of ARD were calculated using linear regression, adjusting for effects of age, age2, and field center (ie, minimally adjusted model), separately in groups composed by sex and ethnicity. The ARD was additionally adjusted for height, weight, diastolic BP, and systolic BP in a fully adjusted model. Multipoint linkage analysis was performed using the GENEHUNTER2 variance components method. Results Suggestive evidence for linkage was found on chromosome 5 at 85 cM in African Americans, with a maximal log of the odds (LOD) score of 2.07. Suggestive evidence for linkage was found on chromosome 1 at 157 cM in whites, with a maximal LOD score of 2.40. Conclusions Our findings suggest that genes present on chromosomes 1 and 5 might influence inter-individual variation in aortic root diameter.