For most of the coronavirus pandemic, the loss of smell and taste have been known as signature symptoms. Loss of sense of smell (anosmia) or taste (ageusia) are distinctive symptoms of COVID-19 and are among the earliest and most often reported indicators of the acute phase of SARS-CoV-2 infection. 1 Early research suggests these symptoms are rarer with the omicron variant.
The precise cause of sensory loss related to Covid is not known, but scientists believe it stems from damage to infected cells in a part of the nose called the olfactory epithelium. A recent study implicates variants situated near two genes: UGT2A1 and UGT2A2. These genes play a role in the physiology of olfactory support cells. Notably, the variant identified in this study also appears to be associated with general ability to smell, which may suggest that those with heightened smell or taste sensitivity may be more prone to notice a loss of these senses resulting from a SARS-CoV-2 infection.