Incidental Findings of Sickle Cell Trait From an Everyday Diabetes Test: Should General Health Care Providers and Testing Centers Report, Retest, or Refer?

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, identified by the routine A1C test, but also several related ethical dilemmas. This article explores issues such as whether informed consent is necessary, how the results should be communicated, how the patient may be affected by knowing their carrier status, the timing of communications, complications caused by partial results, and being a 'healthy carrier' at the same time as potentially experiencing symptoms.