A total of 275 β-thalassemia gene carriers, 44 αβ-compound-thalassemia gene carriers, 186 α-thalassemia gene carriers and 398 non-thalassemia gene carriers were enrolled. MCV and MCH were determined by XE-2100, and hemoglobin electrophoresis was performed by CAPILLARYS 2 system. GAP-PCR and PCR-reverse blot hybridization were used to detect 3 common α-thalassemia genes and 17 common β-thalassemia gene mutations, respectively. The sensitivities, specificities, positive predictive values (PPV) and negative predictive values (NPV) were compared between hemoglobin electrophoresis and the combined determinations of MCV and MCH with hemoglobin electrophoresis in thalassemia diagnosis.

For screening β-thalassemia gene carriers and αβ-compound-thalassemia gene carriers by hemoglobin electrophoresis, the sensitivity was 99.69%, the specificity was 98.28%, the PPV was 96.96%, and the NPV was 99.83%. For screening α-thalassemia gene carriers by the combined determination of MCV with hemoglobin electrophoresis, the sensitivity was 86.56%, the specificity was 83.26%, the PPV was 57.30%, and the NPV was 95.98%. For screening α-thalassemia gene carriers by the combined determination of MCH with hemoglobin electrophoresis, the sensitivity was 92.47%, the specificity was 81.45%, the PPV was 56.39%, and the NPV was 97.66%.

Hemoglobin electrophoresis can determine above 95% β-thalassemia and αβ-compound-thalassemia gene carriers. The combined determination of MCH with hemoglobin electrophoresis can improve sensitivity in thalassemia screening.