Segregation analysis using the unified model.

Segregation analysis is a basic tool in human genetics. It is a statistical method to determine if a trait, continuous or binary, has a transmission pattern in pedigrees that is consistent with Mendelian segregation. Major locus segregation is combined together with multifactorial/polygenic inheritance in the unified model. Segregation analysis as a procedure to identify the presence of segregation at a major Mendelian locus, with/without multifactorial inheritance, is introduced in this chapter. It is illustrated with the program SEGREG in the Statistical Analysis for Genetic Epidemiology (S.A.G.E.) package, which can use either regressive models or the finite polygenic mixed model to incorporate the multifactorial/polygenic component.