Despite these limitations, a number of recent studies suggest the importance of genotype–sex interactions in the genetic architecture of quantitative phenotypes and common diseases, which should motivate the development of robust methods for both assessing and routine testing of genotype–sex interactions in genetic studies. It should be noted, however, that while many linkage studies have reported sex effects, only few have shown that increased lod scores in one sex are not due to chance findings resulting from splitting samples and performing multiple tests, or have explicitly tested for genotype– sex interactions (see refs.45,53 for exceptions). As a result, linkage studies will not be reviewed here. Instead, we first review evidence for genotype–sex interactions in model organisms, and then highlight three recent examples of genotype–sex interactions in human association studies.
