Spectrum of alpha-thalassemia mutations according to immigration, ethnicity in Bursa, Turkey and first observing of SEA double gene deletion

Abstract

Background: Thalassemia syndromes are common in the Mediterranean region, including Turkey. Our aim is investigating the genetic mutation diversity of alpha thalassemia cases in Bursa and to investigate the mutation diversity in relation to the cases' immigration status and ethnic origins.
 Materials and Methods:
 Retrospective analysis was performed on 66 cases aged 1-18 years who were diagnosed as alpha thalassemia carriers by genetic mutation analysis. The patients' complete blood count, ferritin levels, hemoglobin electrophoresis, genetic mutations, immigration status, origin, whether they received iron therapy prior to the diagnosis were all evaluated.
 Results: Of the 66 cases, 53% were female and 47% were male. The most common genetic mutation was the 3.7% deletion with a rate of 51.5%, followed by the heterozygous mutation with a deletion of 20.5 with a rate of 21.20%. SEA double gene deletion homozygous mutation 1.5% and, heterozygous mutation 1.5%. Eleven different genotypes of alpha thalassemia were discovered. While 3.7 deletion heterozygous mutation was most common in cases immigrating from Bulgaria, Syria, and Azerbaijan, FIL deletion mutation was most common in cases immigrating from Georgia, and alpha-2 polyA-2 heterozygous mutation was found in one case immigrating from Greece.
 Conclusion: The most common mutation was 3.7 deletion and SEA double gene deletion was discovered, which had not been discovered in previous studies. With this study, we added to the literature the genetic mutation diversity in Bursa, which sees a lot of immigration.