To address the sensitivity issue due to population stratification, it is necessary to validate the SNP genotyping and perform a test such as the PTDT to validate results and use a program such as UNPHASED. This approach minimizes expense when the case/control sample is derived from an existing family study in which relatives have available DNA for typing. Moreover, we may implement additional application to other populations such as African Americans to compare findings with what we have from the European Americans. This will require extending the techniques described above.
