Beta-thalassemia in southwestern Iran.

Seventeen unrelated beta-thalassemia patients or carriers from Southwestern Iran were examined for the beta-globin gene mutations by polymerase chain reaction amplification of the beta-globin gene and direct genomic sequencing, or by the method of allele-specific oligonucleotide hybridization. Their clinical and hematological characteristics were also recorded. Of 26 potential thalassemia-causing chromosomes examined, 10 different mutations were found. The IVS-II-1 (G-->A) mutation was the most frequent (31%) followed by the IVS-I-6 (T-->C) mutation (15%). Eight mutations were initially described in Mediterranean populations and two were of Kurdish origin. Four of these mutations, both initially described in the Mediterranean region, are reported here for the first time in Iranians. The unexpectedly high number of different mutations that account for beta-thalassemia in this region of Iran suggest migration of chromosomes from distant places and genetic admixture.