Elevated heart rate has been proposed as an independent risk factor for cardiovascular diseases, but their interrelationships are not well understood. In this study, we performed a genome-wide linkage scan in 1,026 individuals (mean age 30.6 years, 54.5% women) from 73 extended families of Mongolia and determined quantitative trait loci that influence heart rate. The DNA samples were genotyped using deCODE 1,039 microsatellite markers for 3 cM density genome-wide linkage scan. Correlation analysis was carried out to evaluate the correlation of the covariates and the heart rate. T-tests of the heart rate were also performed on sex, smoking and alcohol intake. Consequently, this model was used in a nonparametric genome-wide linkage analysis using variance component model to create a multipoint logarithm of odds (LOD) score and a corresponding P value. In the adjusted model, the heritability of heart rate was estimated as 0.32 (P<.0001) and a maximum multipoint LOD score of 2.03 was observed in 77 cM region at chromosome 18. The second largest LOD score of 1.52 was seen on chromosome 5 at 216 cM. Genes located on the specified locations in chromosomes 5 and 18 may be involved in the regulation of heart rate.
Adolescent ; Adult ; Chromosome Mapping/*methods ; Female ; Genetics, Population ; Genome, Human/*genetics ; Genome-Wide Association Study/methods ; *Heart Rate ; Humans ; Linkage (Genetics) ; Male ; Middle Aged ; Mongolia ; Quantitative Trait Loci/*genetics ; Young Adult

High-density lipoprotein (HDL) whose primary role is to transport cholesterol from peripheral tissues to the liver, is associated with the incidence of coronary heart disease. We analyzed HDL cholesterol levels in a genetically isolated population of extended Mongolian families. A total of 1002 individuals (54.5% women) from 95 families were enrolled. After genotyping by use of 1000 microsatellite markers, we performed a genome-wide linkage search with variance component analysis. The estimated heritability of HDL cholesterol was 0.45, revealing that HDL cholesterol was under significant genetic influence. We found peak evidence of linkage (LOD score=1.88) for HDL cholesterol level on chromosome 6(nearest marker D6S1660) and potential evidences for linkage on chromosomes 1, 12 and 19 with the LOD scores of 1.32, 1.44 and 1.14, respectively. These results should pave the way for the discovery of the relevant genes by fine mapping and association analysis.
Cholesterol ; Cholesterol, HDL ; Coronary Disease ; Humans ; Incidence ; Lipoproteins ; Liver ; Lod Score ; Microsatellite Repeats ; Mongolia ; Plasma

High-density lipoprotein (HDL) whose primary role is to transport cholesterol from peripheral tissues to the liver, is associated with the incidence of coronary heart disease. We analyzed HDL cholesterol levels in a genetically isolated population of extended Mongolian families. A total of 1002 individuals (54.5% women) from 95 families were enrolled. After genotyping by use of 1000 microsatellite markers, we performed a genome-wide linkage search with variance component analysis. The estimated heritability of HDL cholesterol was 0.45, revealing that HDL cholesterol was under significant genetic influence. We found peak evidence of linkage (LOD score=1.88) for HDL cholesterol level on chromosome 6(nearest marker D6S1660) and potential evidences for linkage on chromosomes 1, 12 and 19 with the LOD scores of 1.32, 1.44 and 1.14, respectively. These results should pave the way for the discovery of the relevant genes by fine mapping and association analysis.
Cholesterol ; Cholesterol, HDL ; Coronary Disease ; Humans ; Incidence ; Lipoproteins ; Liver ; Lod Score ; Microsatellite Repeats ; Mongolia ; Plasma