The feasibility of genetic dissection of endophenotypes

Endophenotypes are traits that proceed and predict traits of interest. In this special issue, there are a series of papers on genomic analysis of 17 physiologic traits measured by the Minnesota Center for Twin and Family Research that are thought to be endophenotypes for behavioral clinical traits such as addiction and schizophrenia. Because these 17 traits, which can be precisely defined and measured throughout the life of subjects, display variation in normal subjects and are heritable, it is thought that they may be more tractable to genetic dissection. These articles show that these 17 endophenotypes appear to have a similar architecture to the vast majority of traits with complex modes of inheritance. The study identified several genetic loci that play a role in these endophenotypes. It appears that further progress in understanding the genetics of these 17 endophenotypes can be made with an expanded data set.