Perrimond H
Service d'hématologie pédiatrique, Hôpital de La Timone, Marseille, France.
Bull Soc Pathol Exot. 2001 May;94(2):92-4.
Monogenic diseases are very unevenly distributed throughout the world and beta-thalassemies are due chiefly to a large number of point mutations of the beta globine gene. The thalassemia trait (heterozygous thalassemia) can be asymptomatic and diagnosis is established by demonstration of an increased proportion of Hb A2. In the homozygous state (thalassemia major) hypochromic anemia is extremely severe because erythropoiesis is largely ineffective. Regular transfusion is necessary to prevent early death and transfusion therapy is usually initiated in the first year of life after biological diagnosis. Iron chelation is now capable of preventing transfusional haemachromatosis responsible for late mortality. 10% only of patients with homozygous beta-thalassemia have a syndrome of intermediate haematologic severity (thalassemia intermedia). Hb S--beta-thalassemia disease is characterised by a clinical course that resembles more that of Sickle Cell disease than to the thalassemia syndromes.
单基因疾病在全球的分布极不均衡，β地中海贫血主要归因于β珠蛋白基因的大量点突变。地中海贫血性状（杂合子地中海贫血）可能无症状，通过证明Hb A2比例增加来确诊。在纯合状态（重型地中海贫血）下，低色素性贫血极其严重，因为红细胞生成大多无效。定期输血对于预防早期死亡是必要的，输血治疗通常在生物学诊断后的第一年开始。铁螯合现在能够预防导致晚期死亡的输血性血色素沉着症。只有10%的纯合子β地中海贫血患者有中度血液学严重程度的综合征（中间型地中海贫血）。Hb S-β地中海贫血疾病的临床病程更类似于镰状细胞病，而非地中海贫血综合征。
