beta-Thalassaemia intermedia in Lebanon

Approximately one third of thalassaemia patients on record in Lebanon have thalassaemia intermedia. We have analysed three factors in a panel of 73 pa tients with this less severe form of the disease in our population: mild be ta-globin gene mutations, deletions in the alpha-globin gene and the presen ce of a polymorphism for the enzyme Xmn I in the (G)gamma-promoter region. The results show that the most important contributing factor is the beta-ge notype: 68% of patients have a mild beta+ mutation (IVSI-6, cd29, -88 or -8 7), while 26% of patients are positive for the Xmn I polymorphism associate d with increased production of HbF, which showed strong linkage to particul ar mutations (IVSII-1, cd8 and cd30). However, the genotype-phenotype corre lation is difficult, because many patients were initially misdiagnosed as t halassaemia major and were started early on regular blood transfusions, whi ch was stopped later on. This illustrates well the importance of an early a ccurate diagnosis of thalassaemia intermedia for appropriate clinical manag ement.