Clinical and hematological features of codon 17, A-T mutation of beta-thalassemia in Thai patients

Forty-one patients with codon 17, A-T mutation of beta -thalassemia, which is commonly found in Thailand, were studied to determine whether it is poss ible to predict phenotypic severity from genetic factors. The clinical phen otype of homozygotes for codon 17, A-T and compound heterozygotes for codon 17, A-T and beta (+)-thalassemia may be used to predict a severe phenotype with TM. However, the clinical phenotype of compound heterozygotes for cod on 17, A-T and beta (+)-thalassemia or Hb E were variable and could not be accurately predicted. The association of alpha -thalassemia(2) and milder d isease was and was not evident in patients with codon 17, A-T and Hb E. The association between Hb CS gene or the presence of XmnI-(G)gamma polymorphi sm and a mild clinical phenotype is not apparent, indicating the involvemen t of other ameliorating determinants or genetic modifications.