The A1C (HbA1c test) is increasingly used as a diagnostic and screening test for type 2 diabetes (T2DM). With an estimated 8.8% of adults globally having diabetes, effective screening, diagnosis, and monitoring is of major global importance (1). The biomarker of A1C refers to glycated hemoglobin A molecules and has gained prominence in the diagnosis of type 2 diabetes because it offers certain advantages over plasma glucose testing regimens (2). It is well established that some of the hundreds of hemoglobin (Hb) variants, including the clinically relevant HbS, HbE, HbC, and HbD (3,4) may interfere with the validity of A1C results. Thus, testing strategies and tools employing A1C should ideally identify variants when they are present. Incidental findings of Hb variants present several ethical challenges for laboratories, health care providers, patients, and their families. These challenges have, to date, received little attention. This article reviews some of the advantages of detecting sickle cell trait,