Falsely low HbA1c value due to a rare variant of hemoglobin J-Baltimore.

HbA1c values are heavily relied on to assess glycemic control. Hemoglobin variants may interfere with measurements of HbA1c resulting in falsely low values. We present the first report of a rare variant of Hb in a patient with type 2 diabetes, which lead to a falsely low HbA1c.