Identification of the chinese IVS-II-654 (C→T) β-thalassemia mutation in an immigrant Turkish family: Recurrence or migration?

In this study we describe the Chinese IVS-II-654 (C→T) β-thalassemia mutation for the first time in an immigrant Turkish family living in Istanbul and originating from Xanthe, Greece. Four members of the family, representing 3 generations, are heterozygous for this mutation. A detailed family history demonstrated a Greek origin for members of 5 generations with no records of migration or consanguineous marriages. Analysis of polymorphic nucleotides located at the 5' end of the β-globin chromosomes bearing the IVS-II-654 mutation in the family described carried the (AT)₉(T)₅ type of microsatellite sequence and the ACATCCCCA haplotype. These 2 haplotype components favor a non-Eastern Asian origin for this chromosome, hence suggesting an independent origin for the IVS-II-654 mutation described in this family.