The MESA Family study is designed to apply state-of-the-art genotyping and genetic analysis methodologies to delineate the genetic basis underlying atherosclerosis and other subclinical measures of cardiovascular disease by studying the siblings and selected other family members of a subset of individuals who participated in the NHLBI-sponsored Multi-Ethnic Study of Atherosclerosis (MESA-Parent). The MESA Family study is funded as a grant by NHLBI and the Principal Investigator is Jerome Rotter at Cedars-Sinai Medical Center. In addition to six field centers, the study involves a Coordinating Center, a Central Laboratory, two Genetic Analysis Center, and Reading Centers for Computed Tomography, Ultrasound and Retinal Photography. The same ocular protocols for assessing vision and retinal pathology as those used in the parent MESA Study are employed for MESA Family. The main objectives for the MESA Family include the ascertainment and phenotyping of 450 Hispanic American and 450 African American sibships; a 10cM genome-wide search and linkage analysis in these 900 sibships to identify regions likely to contain genes contributing to variation in the cardiovascular (and ocular) phenotypes; and the conduct of genetic association analyses on data from at least 3,000 MESA index cases to investigate (or test previously identified) candidate genes and to evaluate their role of the candidate genes within the different ethnic groups participating in the parent MESA study. Recruitment of MESA Family sibships began in May 2004 and is on-going. As of July 2005, 401 pedigrees were recruited and the list of candidate genes to be investigated in the first phase of the project is being finalized. Genotyping of 3,000 MESA index cases will commence in early fall 2005.