Beta A and beta thal DNA haplotypes in Sicily.

A close association between specific restriction fragment polymorphism patterns and specific mutations in Mediterranean people with thalassemia has been demonstrated by Kazazian et al. (1984). This finding is useful to characterize the number and types of mutations in each ethnic group for setting up prenatal diagnosis in the first trimester of pregnancy by the oligonucleotide technique. For this reason we studied 99 beta thal and 46 beta A chromosomes in the Sicilian population. We found seven different cleavage patterns, not considering two new haplotypes so far uncharacterized. Many of the patients (68.3%) were genetic compounds for different haplotypes while only 31.7% were haplotype homozygotes. They may still be thalassemia compound heterozygotes. These findings confirm the molecular basis of the heterogeneity of beta thalassemia in Sicily.