Thalassemia Phenotypes and Genotypes in Taiwan: A Retrospective Study Based on Thalassemia Screening of Young Men for Military Conscription

摘要

Prenatal thalassemia studies from Taiwan show that one-third of fetuses with genetic abnormalities have beta-thalassemia major (beta-TM). However, the phenotypes and genotypes of adult thalassemia warrant further investigation. From September 2006 to April 2014, 741 male candidates drafted for military service with mean corpuscular volume (MCV) <80 fL and serum ferritin >20 mu g/L were analyzed. The results showed that the detection rates of alpha-and b-thalassemia (alpha- an beta-thal) were 50.20% (372/741) and 49.12% (364/741), respectively. Only five patients (0.67%) were diagnosed with both alpha-and b-thal. The -(SEA)/alpha alpha mutation was found in 76.88% (286/372) of alpha-thal patients. Heterozygous mutations in IVS-II-654 (C > T) and codons 41/42 (-TCTT) accounted for 55.77% (203/364) of b-thal cases. The leukocyte counts for alpha-and b-thal were 6241.74 +/- 1552.99 and 6622.87 +/- 1814.41 +/- 10(9)/L, respectively (p +/- 0.007). The alpha-thal patients had lower red blood cell (RBC) mass (5.85 +/- 0.44 +/- 10(12)/L vs. 6.09 +/- 0.45 +/- 10(12)/L; p < 0.001) and higher hemoglobin (Hb) (12.82 +/- 0.72 vs. 12.35 +/- 0.71 g/dL; p < 0.001) than b-thal patients. Mean serum ferritin values were 169.67 and 241.36 mu g/L, respectively, in alpha- and beta-thal patients (p < 0.001), indicating more profound ineffective erythropoiesis in beta-thal. Only four of the 741 patients underwent further hematological follow-up. Our study suggests that iron overload might be a potential problem in beta-thal patients; therefore, regular follow-up is highly recommended.