Molecular evidences of single mutational events followed by recurrent crossing-overs in the common delta-globin alleles in the Mediterranean area.

The human delta-globin gene (HBD) is one of the beta-like globin genes expressed in adults. In the Mediterranean countries the carriers of delta-thalassemia defects or Hb A2-variants are >1% and about 40/70 known alleles have been found in families with this ethnic origin. The scope of this study was to investigate the variability of the gene and of the chromosomal background in order to highlight the origin and spreading of the delta-globin gene alleles in the Mediterranean area. We carried out the characterization of the delta-globin gene alleles and of RFLP-haplotypes, SNPs and one microsatellite associated with them in 231 carriers originating principally from East Sicily. Seventeen alleles were identified, of which five were new. The chromosomes associated with mutated alleles from unrelated carriers were 158; the allele Hb A2-Yialousa accounted for about 75% of relative frequency, Hb A2-Mitsero for about 8%. The alleles were associated with RFLP 5'-haplotypes "- - - -" or "+ - + +", prevalent in the Mediterranean area, except Hb A2-Mitsero associated with the 5'-haplotype "Benin" "- - - +" and the Hb A2' associated with "+ - - +", both of African origin. Each allele showed linkage with one haplotype with these exceptions. The Hb A2-Yialousa showed heterogeneity of the 5'-haplotype in 2/58 chromosomes; the Hb A2-Mitsero showed SNPs and (A)gamma-microsatellite typical of a "Benin" haplotype found associated with the Hb C and Hb S chromosomes; the Hb A2-Yialousa (14/58 chromosomes), Hb A2-Mitsero, Hb A2-Pylos, Hb A2-Fitzroy showed heterogeneity in the 3'-haplotypes and beta-globin gene SNPs. The Hb A2-Coburg was found associated with the haplotype "+ - + +/+ +" different from that already reported "- - - -/+ -". With the exception of this last allele, the linkage of each mutation with a core of RFLPs or SNPs around or inside the delta-globin locus suggested the unicentric origin of the mutations followed by recurrent recombination events causing the chromosomal background heterogeneity.

Deferiprone versus deferoxamine in patients with thalassemia major: a randomized clinical trial.

Deferiprone has been suggested as an effective oral chelation therapy for thalassemia major. To assess its clinical efficacy, we compared deferiprone with deferoxamine in a large multicenter randomized clinical trial. One-hundred forty-four consecutive patients with thalassemia major and serum ferritin between 1500 and 3000 ng/ml were randomly assigned to deferiprone (75 mg/kg/day) (n = 71) or deferoxamine (50 mg/kg/day) (n = 73) for 1 year. The main measure of efficacy was the reduction of serum ferritin. Liver and heart iron contents were assessed by magnetic resonance. Liver iron content and fibrosis stage variations were assessed on liver biopsy by the Ishak score in all patients willing to undergo liver biopsy before and after treatment. The mean serum ferritin reduction was 222 +/- 783 ng/ml in the deferiprone and 232 +/- 619 ng/ml in the deferoxamine group (P = 0.81). No difference in the reduction of liver and heart iron content was found by magnetic resonance between the two groups. Thirty-six patients accepted to undergo repeat liver biopsy: 21 in the deferiprone and 15 in the deferoxamine group. Their mean reduction of liver iron content was 1022 +/- 3511 microg/g of dry liver and 350 +/- 524, respectively (P = 0.4). No difference in variation of the Ishak fibrosis stage was observed between the two groups. Treatment was discontinued because of reversible side effects in 5 patients in the deferiprone group (3 hypertransamin/asemia and 2 leukocytopenia) and in none in the deferoxamine group. These findings suggest that deferiprone may be as effective as deferoxamine in the treatment of thalassemia major with few mild and reversible side effects.