Family Studies in Genetics

Family studies may be considered a key entry point for research into the role of inherited genetic variation in disease. There are three major kinds of family studies: (1) evaluations of the extent to which a disease or other trait of interest aggregates or clusters within families, and how it is transmitted across the generations; (2) linkage analyses aimed at pinpointing the specific location on one of the chromosomes of a gene containing a mutation that has a major or moderate effect on disease risk; and (3) association studies aimed at finding common gene variants that have smaller but still medically important effects on disease severity or disease incidence. All three of these kinds of family studies are considered in this entry.