Like many viruses, the SARS-CoV-2 is a shape-shifter. And that may make it harder to detect. With this in mind, the U.S. Food and Drug Administration (FDA) is warning clinical laboratories and health care providers of the risk that genetic mutations to the virus may lead to false negative test results. The Diagnostic Challenge The first and vast majority of tests with FDA emergency use authorization (EUA) for SARS-CoV-2 are molecular assay designed to detect specific RNA sequences found in the viral genome. However, the SARS-CoV-2 virus mutates regularly, resulting in several genetically unique variants, each with different RNA sequences. The presence of SARS-CoV-2 genetic variants in a patient sample can potentially change the performance of the SARS-CoV-2 test. If a molecular test is not engineered to detect the particular sequences associated with these variants, it may miss the variant leading to the false conclusion that the test subject does not have the virus. The resulting false negative may prevent the subject from receiving necessary treatment and enhance the risk of infection by keeping him/her out of self-isolation. [freereport] Molecular tests designed to detect multiple SARS-CoV-2 genetic targets are less susceptible to the effects of genetic variation than tests designed […]