alpha alpha alpha anti-4.2 Haplotype and heterozygous beta null thalassemia in a Sicilian family.

The presence of the alpha alpha alpha anti-4.2 haplotype and heterozygous beta null thalassemia in a Sicilian family is described. These findings confirm the presence in Italy of a leftward deletion (-alpha 4.2) and indicate that this may not be rare. Furthermore, although the beta thalassemia determinant in this family has a severe expression, the interaction with the triplicated alpha gene does not necessarily express itself as thalassemia intermedia.