Background The patients who conducted hemoglobin A1c (HbA1c) testing in clinical laboratory showing high hemoglobin F (HbF) level (≥1.5%) or abnormal Hb peak indicated possibility of thalassemia. Therefore, current investigation aims to analysis the occurrence of thalassemia in such populations and predict main influence factors by using different statistical model.
Methods HbA1c concentration was detected by using TOSOH HLC-723G8 glycated hemoglobin analyzer. SNaPshot SNP typing and AccuCopy technology were employed to detect 69 single mutation sites and 6 deletion mutations in common α- and β-thalassemia-related pathogenic genes.
Results Total 126 patients endured high HbF level or abnormal Hb peak during HbA1c detection and 66.7% subjects (n=84) showed thalassemia mutations. Three heterozygosity mutations, including c.52A>T (p.K18*), c.-78A>G and c.126_129delCTTT(p.F42Lfs*19) present in HBB gene were newly identified in thalassemia. --SEA/αα mutation demonstrated the youngest ages (P<0.001). 17M (P<0.001) and 41/42M (P<0.01) mutations with β-thalassemia showed higher HbF level compared with patients without thalassemia mutations. Except for -α3.7, mutations in thalassemia showed lower level of MCH and MCV compared with patients without thalassemia mutations. Patients with thalassemia mutations showed younger age (P<0.001), lower Hb (P<0.001), MCV and MCH level (P<0.001), higher RBC count (P<0.001) and PDW level (P=0.007) than patients without thalassemia mutations. Three statistical model indicate MCV is the most valuable independent factor for predicting thalassemia, and ROC (receiver operating characteristic) curves analysis of AUC of 0.855 (95%CI [0.787-0.923], P<0.001) with MCV.
Conclusions High HbF level (≥1.5%) or abnormal Hb peak present in HbA1c testing indicated high incident rate of thalassemia. Therefore, further genetic testing was advised for such patients. MCV is the most valuable independent predicting factor for subjects having thalassemia.