| Abstract: | Reviews research that has focused on specifying the genetic mechanisms involved in the familial transmission of vulnerability to schizophrenia. The importance of specifying the mechanism and methodological issues involved in genetic modeling are discussed. Models of genetic transmission are described and analyzed, including single major locus models, polygenic models (such as limited loci polygenic models and multifactorial polygenic models), and mixed models. Findings provide little support for the mechanism of single major locus inheritance. Although a mechanism involving 2, 3, or 4 loci cannot be ruled out, there is no compelling support for such models. The multifactorial polygenic model has received the most support and indicates that genetic factors play a greater role than cultural factors in familial transmission. At present, results neither support nor refute a mixed genetic model including both a multifactorial component and a single major locus. Implications of genetic heterogeneity and methodological deficiencies that limit the interpretability of these studies are discussed. (79 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) |
