This component contains the genotyping and DNA collection portions of the proposal. We propose building upon the existing oligonucleotide ligation assay currently in use in the Center for Human Genetics to develop a high-throughput SNP genotyping assay. The OLA assay has the advantage of being highly flexible, cost effective, accurate, good for small large labs, as no expensive equipment is necessary, and can be multiplexed. We will investigate the dynamics of using PCR multiplex for OLA analysis, develop standard protocol for routine OLA multiplexes, and adapt the procedure to both 8 and 96 channel capillary sequencers. This will be based on our highly successful Flourescent Allele Static Scanning Technique (FASST), which we have used to genotype 700,000 microsatellite in the past year. Once the procedure is developed, we will use it to test the SNPs developed in Component 3, SNP Discovery, from the genes identified in the expression studies. In addition, we will investigate whether genotyping SNPs on DNA obtained from the expression donors can efficiently reduce the number of candidate genes genotyped on a larger cardiac data set. This data set of 2000 individuals will be collected to observe if these expression/association approach to complex disorders will be successful.