An improved method for the diagnostic approach of alpha+-thalassaemia.

An improved method for the diagnostic approach of alpha(+)-thalassaemia is described. The method is based on five common parameters: absence of iron deficiency, mild morphological abnormalities of erythrocytes, normal or slightly reduced erythrocytic indices MCV and MCH, normal chromatographic findings, and presence of haemoglobin H inclusions in erythrocytes with methyl-violet stain after, but not before, incubation with oxidant agent. We studied by DNA analysis, 58 subjects fulfilling the above mentioned diagnostic criteria and we found that 50 of them (86.2%) had a alpha-globin gene defect. In the remaining eight subjects (13.8%) no alpha-gene defect could be documented with the techniques used in the DNA analysis, which detect the six well-known alpha(+)-thalassaemic defects in the Greek population. We conclude that the improved method, we described has a high sensitivity and accuracy in the screening of alpha(+)-thalassaemia.