A therosclerosis is one of the most common causes of death and disability worldwide. 1 Because it is more common in the elderly population, its public health impact will continuously increase with growing life expectancy. Several genetic and environmental risk factors have been identified to be associated with atherosclerosis and 2 of its most deleterious clinical manifestations myocardial infarction and stroke.2 Common carotid intima-media thickness (CIMT) is a widely used marker for subclinical atherosclerosis.3 CIMT is influenced by genetic factors and by classical risk factors, such as smoking, blood pressure, diabetes mellitus, or plasma lipid levels. 4 The consideration of this endophenotype in genetic studies has several advantages: CIMT can be quantified, is easily accessible with a noninvasive method, and is an early indicator of atherosclerosis and a predictor for myocardial infarction and stroke.
5-7Few genome-wide linkage studies have been conducted to map the genetic factors influencing CIMT and did report inconsistent results. [8][9][10][11] One explanation might be that the measurement protocols for CIMT varied between studies as did the genetic background of the study populations and the genotyping technologies. Despite these differences, the largest and most recent genome-wide association meta-analysis, includingBackground and Purpose-Carotid intima-media thickness is a marker for subclinical atherosclerosis that predicts subsequent clinical cardiovascular events. The aim of this study was to identify chromosomal loci with linkage or association to common carotid intima-media thickness. Methods-Nuclear families were recruited using the single parental proband sib-pair design. Genotype data were available for 546 individuals from 132 nuclear families of the Bonn IMT Family Study using the Affymetrix GeneChip Human Mapping 250K Sty chip. Multipoint logarithm of the odds (LOD) scores were determined with the quantitative trait locus statistic implemented in multipoint engine for rapid likelihood. Linkage analysis and family-based association tests were conducted. Data from 2471 German participants from the HNR (Heinz Nixdorf Recall) Study were used for subsequent replication. Results-Two new genomic regions with suggestive linkage (LOD>2) were identified on chromosome 4 (LOD=2.26) and on chromosome 17 (LOD=2.01). Previously reported linkage findings were replicated on chromosomes 13 and 14. Fifteen single nucleotide polymorhisms, located on chromosomes 4, 6, and 9, revealed P<10 -4 in the family-based association analyses. One of these signals was replicated in HNR (rs2416804, 1-sided P=1.60×10