Beta thalassaemia mutations in the Turkish population.

thalassaemia mutations in the Turkish population Only sparse information is available at present on the molecular pathology of the thalassaemias in the Turkish population.In this study, we have carried out haplotype analysis on the globin gene cluster and characterised the thalassaemia mutations by oligonucleotide hybridisation in 10 Turkish patients with thalassaemia major, who have been followed at the Department of Pediatrics at Ankara University.Haplotype analysis and oligonucleotide hybridisation were carried out as previously described.' 2 We used three oligoprobes complementary to the most fre- quent thalassaemia mutations in Mediterraneans, namely the G-A substitution at position 110 of the first intervening sequence of the globin gene (13k IVS-1, nt 110), the C-T substitution at codon 39 (13039), and-the T-C substitution at position 6 of IVS-1 (13k+ IVS-1, nt 6).Oligonucleotide analysis showed the IVS-1, nt 110 mutation in 13 out of 20 (65%) thalassaemia chromosomes investigated.In the remaining chromosomes the presence of 1339 and the IVS-1, nt 6 mutations was excluded (table).A repre- sentative autoradiogram is shown in the figure.Four patients were homozygous for the 13i IVS-1, nt 110 mutation and five were compound heterozygotes for this mutation and a different [3 thalassaemia mutation, not yet characterised.The IVS-1, nt 110 mutation was contained without exception in haplotype I according to the nomenclature of Orkin et al.2The polymorphic A vall site