Study Methods to Find Disease Genes in Complex Diseases

Lee, Young Ho; Ji, Jong Dae; Song, Gwan Gyu

Abstract

Most common diseases are complex genetic traits. Identifying the genes that underlie the variation in the diseases has been challenging. Two major approaches have been used to map genetic variants that influence disease risk: linkage analysis and association study. Linkage analysis tests for the co-segregation of a marker and disease phenotype within a pedigree, whereas association study tests for differences in marker allele frequencies between patients and a control population. Linkage analysis is applied without any prior knowledge of the biological basis of the disease. In association study, genes with a known function with the potential to influence the disease phenotype are investigated for a direct role in disease. No single method is sufficient. A multi-strategy approach to the mapping of complex diseases is required. We review the different types of genetic studies to find genes for complex genetic traits.