Haemoglobin synthesis in 28 obligatory cases for α-thalassemia traits

Abstract

In the Far East two types of α-thalassemia genes, namely α-thalassemia 1 (α-thal 1 ) and α-thalassemia 2 (α-thal 2 ) exist. Definite diagnosis of the α-thal 1 and α-thal 2 traits is very difficult because their hematological findings are minimally abnormal or normal. This study attempts to characterize the heterozygotes by hemoglobin chain synthesis in reticulocytes from obligatory cases of the α-thal 1 and α-thal 2 traits. Twelve parents of babies with hemoglobin Bart's hydrops fetalis (obligatory α-thal 1 trait) had the mean total radioactivity α/β ratio of 0.76±SD 0.04, while that of 7 normal controls was 1.06±SD 0.04. The α/β globin chain ratios of 16 cases, who were either parents or offspring of patients with hemoglobin H disease, were found to segregate into 2 groups, i.e. 0.78±SD 0.03 (10 cases) and 0.92±SD 0.03 (6 cases), probably representing the α-thal 1 and α-thal 2 traits respectively. The hematological data of the first group showed definite hypochromic microcytic red cells, similar to thoseof the parents of the hydrops. The second group had significantly higher mean corpuscular hemoglobin than the first group, compatible with α-thal 2 trait. Our globin chain synthesis study thus appears to be capable of discriminating normal, α-thal 1 and α-thal 2 traits. © 1975 Springer-Verlag.