[DNA diagnosis in medicine]

Abstract

About 950 genes (or a part of them) have been cloned. Using them as probes, DNA diagnosis is now available in hundreds of hereditary diseases and some malignant diseases. In many of them, detailed analysis into the mechanisms underlying the diseases has become possible. Examples of this capability include 21 hydroxylase deficiency, amyloid polyneuropathy, Duchenne/Becker muscular dystrophy, and CML. About one third of the cloned genes show RFLPs (restriction fragment length polymorphisms). In addition "random" DNA fragments have been cloned, many of them can also be used to detect RFLPs. An RFLP study has proven very useful in the preclinical/prenatal diagnosis of hereditary diseases even though gene-action is unknown (e.g., Huntington disease and von Recklinghausen disease). DNA diagnosis has also been found to be very useful in the detection of microorganisms, minute chromosome changes (e.g., XX males) and for forensic purposes. The techniques and understanding of DNA diagnosis have become mandatory in many areas of medicine.