RT Book, Section A1 Todd, John A. A2 Valle, David L. A2 Antonarakis, Stylianos A2 Ballabio, Andrea A2 Beaudet, Arthur L. A2 Mitchell, Grant A. SR Print(0) ID 1181401243 T1 Multifactorial Diseases: Ancient Gene Polymorphism at Quantitative Trait Loci and a Legacy of Survival During Our Evolution T2 The Online Metabolic and Molecular Bases of Inherited Disease YR 2019 FD 2019 PB McGraw-Hill Education PP New York, NY SN 9780071459969 LK ommbid.mhmedical.com/content.aspx?aid=1181401243 RD 2024/04/23 AB Most genetic diseases do not follow a Mendelian paradigm; instead they are multifactorial having biological components that are both in the host (biological variation) and in the environment (exposure to experiences that are selective and impinge on health). In addition to alleles that confer susceptibility (for resistance) under certain conditions, there could be a constellation of alleles at different loci affecting proteins that must interact, in this way accounting for a complex trait. This chapter addresses, in a brief way, how one begins to approach mapping the genomic bases of complex traits.