Dr. Risch focuses on the development and application of statistical methods to address problems in human population genetics and genetic epidemiology. This has involved numerous projects using linkage analysis and positional cloning to identify novel disease genes, such as the genes causing hemochromatosis and torsion dystonia, as well as methodology for dissection of genetically complex traits including autism, hypertension, and multiple sclerosis. He has also spearheaded the approach of genome-wide association studies, the recent mainstay of human genetic analysis, and developed with investigators at Kaiser Permanente Northern California Division of Research a large genetic epidemiology research cohort on aging.