Spurious elevation of hemoglobin A1c by hereditary persistence of fetal hemoglobin.

We present the case of a 61- year-old black woman with a diagnosis of type 2 diabetes and a falsely elevated hemoglobin A1c (HbA1c) due to hereditary persistence of fetal hemoglobin. Physicians and allied health care professionals are alerted to this potentially significant problem in the diagnosis and management of diabetes mellitus (DM), particularly in the wake of the Diabetes Complications and Control Trial when "strict" glycemic control assessed by HbA1c is now the standard of care.