Genetic testing holds a special place in revealing genetic changes that are involved in causing hereditary cancers. Testing laboratories have been encouraged by a new research study at UT Southwestern Medical Center to update their records and aware physicians when the genes are reclassified. Genetic testing results from 1.45 million people were revised which depicted the subsequent reclassification of likely or unlikely cancer association of about 25 percent of “variants of uncertain significance”.
Genetic variations are classified as “benign,” “likely benign,” “variant of uncertain significance,” “likely pathogenic,” or “pathogenic”. Reclassification of a variant to be “pathogenic” might matter a lot to the patient. A patient might add MRI scans to their mammogram screening program or want to have prophylactic surgery if he has a broken BRCA gene. Likewise, if a variation is reclassified as “benign” from “variant of uncertain significance”, it can be very vital for a patient’s relief.
A usual gene contains about 27,000 base pairs (A-T, G-C) that make up a DNA whereas a few genes comprise of 2 million of these bases, increasing the chances of variations. Dr. Theo Ross, Professor of Internal Medicine and senior author of the study stated that new families having an increased inherited predisposition to cancer might be identified. The detailed genetic studies on their DNA might disclose new information which can further be analyzed and verified by biochemical, collective familial and functional studies leading to the development of new therapeutic strategies.
Journal of the American Medical Association (JAMA) published a study that reviewed test results for hereditary cancer genes for which 60,000 amended reports were issued out of 1.67 million initial reports. Reclassification process changed about 24.9 percent “variant of uncertain significance” to the majority being benign. This study implies that testing laboratories must review gene variant information regularly alerting the physicians about it. Physicians must be aware of common reclassifications and rapidly advancing knowledge about gene variants. Patients should be informed of reclassifications by their physicians so that they can make well-suited choices.