ALPHA-THALASSEMIA CARRIER IDENTIFICATION BY DNA ANALYSIS IN THE SCREENING FOR THALASSEMIA

Differentiation between heterozygous alpha-thalassemia and several phe notypically resembling alleles at the beta-globin gene cluster such as coinherited delta- and beta-thalassemia or gamma delta beta-thalassem ia is a critical step in genetic counseling. In this paper we report o ur experience in the identification of the alpha-thalassemia carrier s tate using polymerase chain reaction (PCR)-based methods, and the feas ibility and simplification of screening for thalassemia using this app roach. alpha-Globin genotype was determined by PCR-based method in 526 adult subjects with reduced mean corpuscular volume (MCV) and mean co rpuscular hemoglobin (MCH), normal hemoglobin A(2) end F, and normal s erum iron. To verify the reliability of the protocol used, in 68 of th ese subjects we performed globin chain synthesis analysis and in 101 w e determined alpha-globin genotype by Southern blot analysis. Five hun dred twenty-one (99%) of 526 subjects examined were identified as carr iers of one or two alpha-thalassemia alleles. The identification of th e alpha-thalassemia carrier state may be fast and accurate by PCR-base d method, avoiding other cumbersome and expensive methods such as glob in chain synthesis and Southern blot analysis. (C) 1998 Wiley-Liss, In c.