Molecular approaches to the diagnosis of male infertility

The introduction of the polymerase chain reaction (PCR) as a technique to selectively amplify and identify specific DNA and RNA sequences has revolutionized the field of molecular medicine. Application of these newly developed molecular techniques to the field of male infertility has made the delineation of subtle causes of infertility-an inapparent genital tract infection, immune system activation within the genital tract, mutations in sperm mitochondrial or chromosomal DNA, alterations in sperm components involved in receptor-ligand interactions, and production of sperm autoantibodies-all increasingly amenable to clinical analysis. Continued investigations at the molecular level of the causes of male infertility will also lead to novel treatment regimens as well as development of new methods of fertility regulation.