Molecular medicine: a primer for clinicians--Part VI: Introduction to genetic testing.

Application of the tools of molecular biology to clinical medicine is most apparent than in the development of DNA-based diagnostic and predictive tests. Such tests allow direct examination of the DNA of individuals for the presence or absence of the causative or predisposing molecular defect for a disease or condition. In this and the next two papers, in our series, we will discuss various aspects of genetic testing. We will consider the different types of testing, their current and potential clinical applications and discuss some of the major ethical and legal issues that genetic testing poses.