Leoni G B, Rosatelli C, Vitucci A, Addis M, Loi A, Tannoia N, Cao A
Istituto di Clinica e Biologia dell'Età Evolutiva, Università degli Studi di Cagliari, Italia.
Acta Haematol. 1991;86(4):174-8. doi: 10.1159/000204829.
We investigated the molecular bases for a mild phenotype by alpha-, beta- and gamma-globin gene analyses in 22 patients with transfusion-independent thalassemia intermedia (15) or a late-presenting form of thalassemia major (7) originating from Puglia, a region of southern Italy. Twenty-two patients with thalassemia major served as controls. The beta+ IVS-I nt 6 of the beta-globin gene and the C----T substitution at position -158 5' of the G gamma-globin gene were detected more frequently in patients with thalassemia intermedia or late-presenting thalassemia major considered together as compared to those affected by typical transfusion-dependent thalassemia major. Three of 15 patients with thalassemia intermedia had the triple alpha-globin gene arrangement in the heterozygous (2) or homozygous state (1) in association with heterozygous beta zero-thalassemia. From these results, we may conclude that the inheritance of a mild beta-thalassemia allele such as the beta+ IVS-I nt 6 mutation, in the homozygous or heterozygous state, the coinheritance with homozygous beta zero-thalassemia of the -158 (C----T) G gamma gene promoter mutation and the presence of heterozygous beta-thalassemia/triple alpha-globin gene arrangement are the most common reasons accounting for the development of attenuated forms of beta-thalassemia in Puglia.
我们通过对22例来自意大利南部普利亚地区的非输血依赖型中间型地中海贫血患者（15例）或迟发性重型地中海贫血患者（7例）进行α、β和γ珠蛋白基因分析，研究了轻型表型的分子基础。22例重型地中海贫血患者作为对照。与典型的输血依赖型重型地中海贫血患者相比，中间型地中海贫血或迟发性重型地中海贫血患者中，β珠蛋白基因的β + IVS-I nt 6和Gγ珠蛋白基因5'端-158位的C→T替换检测更为频繁。15例中间型地中海贫血患者中有3例存在杂合（2例）或纯合（1例）状态的三重α珠蛋白基因排列，并伴有杂合β0地中海贫血。从这些结果中，我们可以得出结论，在普利亚地区，导致轻型β地中海贫血发生的最常见原因是纯合或杂合状态下轻度β地中海贫血等位基因（如β + IVS-I nt 6突变）的遗传、-158（C→T）Gγ基因启动子突变与纯合β0地中海贫血的共同遗传以及杂合β地中海贫血/三重α珠蛋白基因排列的存在。
