Beta zero and beta+ thalassemia genes in northern Greece.

In an attempt to estimate the prevalence of beta thal zero and beta thal+ thalassemia genes in northern Greece we analyzed hemoglobin samples of 32 subjects with sickle cell thalassemia (beta s/beta thal), from an area of northern Greece (Chalkidiki, 22-24E, 41-42N), where thalassemia and sickle cell disease are common. 24 subjects had no detectable Hb A and only 8 had Hb A ranging grossly between 3-5 per cent in six patients and 10-15 per cent in two patients. Thus the estimate of the relative frequency of the beta thal zero to the beta thal+ was found to be 0.75 +/- 0.077. For the beta thal+ gene, our findings are in agreement with all other Greek investigations in that it is associated with a low or very low presence of Hb A. As to frequencies, however, our findings differ significantly from results reported from other Greek investigators who examined mainly the population of Athens, and this may be explained by an uneven distribution of the various types of thalassemia genes in the various parts of Greece.