Diagnostic molecular pathology: current techniques and clinical applications, part I

George J. Netto, MD, Rana D. Saad, PHD, and Peter A. Dysert II, MD

Recent revolutionary progress in human genomics is reshaping our approach to therapy and diagnosis. Nucleic acid-based testing is becoming a crucial diagnostic tool not only in the setting of inherited genetic disease (e.g., cystic fibrosis and hemochromatosis) but in a wide variety of neoplastic and infectious processes. Following diagnosis, molecular testing can help guide appropriate therapy by identifying specific therapeutic targets of several newly tailored drugs, thus playing an integral role in the application of pharmacogenomics. Molecular diagnostics provides the necessary underpinnings for any successful application of gene therapy or biologic response modifiers. It offers a great tool for assessing disease prognosis and therapy response and detecting minimal residual disease. It is estimated that by the year 2005, more than 5% of all laboratory testing will be based on DNA or RNA analysis (1).
The newly established molecular pathology laboratory at Baylor University Medical Center positions our institution to provide state-of-the-art molecular testing as an integrated consultative element of our advanced patient care. This, the first of a 2-part article, provides a general review of some principles and applications of molecular diagnostic techniques such as polymerase chain reaction (PCR), fluorescent in situ hybridization (FISH), spectral karyotype imaging (SKI), and DNA chip technology.