Alpha-thalassemic traits are common in the Taiwanese population: usefulness of a modified hemoglobin H preparation for prevalence studies.

The aim of this study was to determine the crude prevalence of alpha-thalassemia traits in Taiwan. A total of 1435 healthy employees from a statewide company were randomly screened by complete blood count determination with indices. Subjects with mean corpuscular volume less than 80 fl were analyzed by hemoglobin electrophoresis on cellulose acetate to exclude beta-thalassemia and with serum ferritin to exclude iron deficiency. Modified hemoglobin H inclusion staining was performed to confirm the diagnosis of alpha-thalassemia traits, and DNA probe studies were used to confirm the validity of this test. The overall prevalence rate of alpha-thalassemia trait was 3.4% (48 out of 1435). In persons of mainland Chinese origin, prevalence was 0.4%, and among persons of Taiwanese origin, it was 4.0% (47 out of 1171). We conclude that alpha-thalassemia traits are common genetic disorders in Taiwan and that antenatal screening is advised to reduce the frequency of occurrence of hemoglobin Bart's hydrops fetalis. The methods we used proved to be reliable and inexpensive.