Research article

Evidence for a gene influencing heart rate on chromosome 5p13-14 in a meta-analysis of genome-wide scans from the NHLBI Family Blood Pressure Program

Jason M Laramie^1,2 , Jemma B Wilk^1,3 , Steven C Hunt⁴ , R Curtis Ellison³ , Aravinda Chakravarti⁵ , Eric Boerwinkle⁶ and Richard H Myers^1,3

¹Department of Neurology, Boston University School of Medicine, Boston, MA, USA

²Department of Bioinformatics, Boston University, MA, USA

³Section of Preventive Medicine and Epidemiology, Department of Medicine, Boston University School of Medicine, Boston, MA, USA

⁴Cardiovascular Genetics, University of Utah, Salt Lake City, UT, USA

⁵Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA

⁶Human Genetics Center, University of Texas-Houston Health Science Center, Houston, TX, USA

author email corresponding author email

BMC Medical Genetics 2006, 7:17doi:10.1186/1471-2350-7-17

Published:	1 March 2006

Abstract

Background

Elevated resting heart rate has been shown in multiple studies to be a strong predictor of cardiovascular disease. Previous family studies have shown a significant heritable component to heart rate with several groups conducting genomic linkage scans to identify quantitative trait loci.

Methods

We performed a genome-wide linkage scan to identify quantitative trait loci influencing resting heart rate among 3,282 Caucasians and 3,989 African-Americans in three independent networks comprising the Family Blood Pressure Program (FBPP) using 368 microsatellite markers. Mean heart rate measurements were used in a regression model including covariates for age, body mass index, pack-years, currently drinking alcohol (yes/no), hypertension status and medication usage to create a standardized residual for each gender/ethnic group within each study network. This residual was used in a nonparametric variance component model to generate a LOD score and a corresponding P value for each ethnic group within each study network. P values from each ethnic group and study network were merged using an adjusted Fisher's combining P values method and the resulting P values were converted to LOD scores. The entire analysis was redone after individuals currently taking beta-blocker medication were removed.

Results

We identified significant evidence of linkage (LOD = 4.62) to chromosome 10 near 142.78 cM in the Caucasian group of HyperGEN. Between race and network groups we identified a LOD score of 1.86 on chromosome 5 (between 39.99 and 45.34 cM) in African-Americans in the GENOA network and the same region produced a LOD score of 1.12 among Caucasians within a different network (HyperGEN). Combining all network and race groups we identified a LOD score of 1.92 (P = 0.0013) on chromosome 5p13-14. We assessed heterogeneity for this locus between networks and ethnic groups and found significant evidence for low heterogeneity (P ≤ 0.05).

Conclusion

We found replication (LOD > 1) between ethnic groups and between study networks with low heterogeneity on chromosome 5p13-14 suggesting that a gene in this region influences resting heart rate.