A mistaken diagnosis of type 2 diabetes due to hemoglobin N-Baltimore.

Glycohemoglobin (HbA1c) estimation is the gold standard for assessing long-term glycemic control in diabetic patients. Some hemoglobin variants interfere with HbA1c assay, thus, limiting its utility. Over 150,000 diabetic patients are estimated to have hemoglobin variants in the United States; but this number may be up to 30% in some parts of the world. Although, most of the hemoglobinopathies are clinically silent, some of them cause biochemical aberrations, which could interfere with HbA1c assay. However, hemoglobin N-Baltimore has not been reported to give false HbA1c estimation. We present a woman with mistaken diagnosis of diabetes due to hemoglobin N-Baltimore that produced a spuriously elevated HbA1c level.