Genetics of schizophrenia: I. Familial patterns and mode of inheritance.

The purpose of this article is to review and condense the available literature on genetic modeling in schizophrenia research. The principles underlying genetic models and the various applications of these models to family data are reviewed. It is concluded that despite the advances in statistical genetics, the mode of inheritance of schizophrenia remains elusive. The conflicting results are attributed to variation in methods for data collection and analysis and to the heterogeneous nature of the disorder. The possibility is also raised that most previous genetic analyses of schizophrenia may have been compromised by methodological drawbacks. Although the use of advanced genetic models in conjunction with adequate data may shed more light on the genetic contribution to schizophrenia, the limitations of this approach in genetically heterogeneous disorders must be recognized. Alternative methods, such as studies with biological susceptibility traits and genetic markers, may be more useful in unraveling the specific genetic components that underlie the transmission of schizophrenia.