Issues in Genetic Testing

Abstract

“Issues in Genetic Testing” was the theme for the Eighth Clinical Chemistry Forum of the American Association for Clinical Chemistry. The 2-day meeting was held in Arlington, Virginia, on November 3 and 4, 1998, and was jointly sponsored on this occasion by the Association for Molecular Pathology. Manuscripts of five of the meeting presentations have already been published in their entirety (1)(2)(3)(4)(5). The following is a summary of the remaining papers presented at the meeting. The opening presentation by Bradley W. Popovich , PhD, Director, DNA Diagnostic Laboratory, and Director, Clinical Genetic Services Laboratory, Oregon Health Sciences University, set the background for the conference by describing the evolution of DNA diagnostic testing. DNA tests generally are extremely accurate, minimally invasive, and cost-effective. Many hundreds of genetic conditions are already diagnosed through DNA testing. The number and variety of genetic tests will expand rapidly as an outgrowth of the Human Genome Project. ### differences between genetic and traditional laboratory tests Those who provide genetic counseling need to understand that DNA tests often require biological specimens from both the patient and other biological relatives, which clearly differentiates genetic testing from other tests. The information gained from DNA testing will not only be used by the physician to manage the patient’s treatment or care, but also has implications for other family members. Genetic tests can detect a predisposition to a disease, a condition that may or may not occur. Other genetic tests detect presymptomatic disease, a condition that is already present but whose symptoms have not yet developed. Three methods predominate genetic testing: Southern blot analysis, PCR, and DNA sequencing. Southern blot analysis has been used since the early 1980s, but it is extremely labor-intensive and the turnaround time is ∼1 to 2 weeks. The cost is between $250 and $500 per test. …