A Rare Hemoglobin Variant Detected in a Pregnant Chinese Woman.

ABSTRACT

BACKGROUND: Hemoglobin Variant (HBBc.155 C>A) is a rare mutation caused by ß-globin gene mutation called Hemoglobin North Manchester. So far, its existence has no adverse effect on human body, and it is a rare benign hemoglobin variant. METHODS: We reported a 32-year-old pregnant woman with discordant HbA1c and glucose measurements. In 75 g oral glucose tolerance test (OGTT), the pregnant woman got hyperglycemia at 1h-OGTT and 2h-OGTT. However, the pregnant woman had a low HbA1c of 3.9%. Subsequently, gene sequencing identified a rare mutation in the gene (HBBc.155 C>A). RESULTS: We report for the first time that a case of North Manchester mutation in a Chinese female patient. In this case, it was found that the North Manchester variant could affect the examination of HbA1c when measured by ion-exchange high-performance liquid chromatography (HPLC), causing in falsely low HbA1c. CONCLUSIONS: Hemoglobin variants may lead to false HbA1c measurement. Clinicians should consider hemoglobin variants when HbA1c results are inconsistent with other laboratory tests.