Objective: To analyze the molecular abnormalities of beta-thalassemia intermedia in a Korean family with thalassemia intermedia.
Methods: Polymerase chain reaction (PCR), Southern blot hybridization and double strand DNA cycle sequencing were used to analyse alpha, beta and gamma globin gene organization.
Results: In the Korean family the interaction between a triplicated alpha-globin locus and a heterozygous beta-thalassemia gave rise to a clinical phenotype of thalassemia. The molecular defect was a heterozygosity for a single beta-thalassemia mutation (beta IVS-II-1 G-->A) and a triplicated alpha-globin gene (alphaalpha/alphaalphaalpha(anti 3.7)).
Conclusion: Beta-thalassemia heterozygotes conjuncted with alpha-globin gene triplication was the major cause of the beta-thalassemia intermedia in this Korean family.