A-176 Do you have a hemoglobin variant?

Abstract Background Hemoglobinopathies are the most common genetically inherited red blood cell disorder. While there are more than 1,000 hemoglobin variants currently identified, the most common ones include hemoglobin S, Hemoglobin C and hemoglobin E. Patients with homozygous variants are usually identified at young age due to symptoms, whereas patients with heterozygous variants (carriers) can be undiagnosed due to clinically benign nature. Although at low risk, extreme conditions such as high-intensity physical activity can lead to serious health issues in sickle cell trait (carriers). Moreover, children from carrier parents may have homozygous conditions that can produce devastating consequences. This study is to find out a rough estimate of patients’ awareness of their own carrier state of a hemoglobin variant in the population of our medical center. Methods Hemoglobin A1c (HbA1c) is performed on the BioRad D-100 in our laboratory. It is a HPLC-based technology, similar to the BioRad VARIANT II that performs the hemoglobin variant analysis with the Beta-Thal program. Although HbA1c results are not based of any peaks after A0, any variants, if present, are marked in designated windows. A medical chart review is performed, and if the condition of hemoglobin variant is not mentioned, it is considered as “undiagnosed”, and vise versa. Results In the duration of 95 days, a total of 35684 HbA1c samples were analyzed. Of those, 491 samples (1.4%) were marked with hemoglobin variant present. The rest of the samples (98.6%, n=35193) had no hemoglobin variant marked. Of the 491 samples marked with variants, hemoglobin S accounted for 72.5% (n=356), hemoglobin C accounted for 19.1% (n=94), hemoglobin E accounted for 4.9% (n=24), and the rest were marked with various hemoglobinopathies (3.5%, n=17). In any category, vast majority of the patients were “undiagnosed”, ranging from 85% to 100%. Only 8% to 15% of the patients were aware of their hemoglobin variant. There is no difference of awareness in different age groups, either, given that hemoglobin variants are included in the Newborn Screen Program in most states. One patient, at age 55, with hemoglobin C disease (HbCC) was undiagnosed. Conclusions Although most patients who are carriers of hemoglobin variants can have a normal life and often go undiagnosed, it still poses risks in specific situations. Sickle cell trait patients are under risks at high-intensity physical activity. Carriers of hemoglobin C and hemoglobin E often have microcytosis but are misled as iron-deficiency anemia. Screening of hemoglobinopathies has become increasingly important in antenatal diagnosis and prevention of hemoglobin disorders.