Investigation of alpha globin gene mutations by complementary methods in Antalya

Abstract

Alpha (?) thalassemia is one of the hemoglobinopaties that is inherited by autosomal recessive mode. It is caused by mutations on alpha-1 and alpha-2 globin genes. Deletional type mutations of globin genes have commonly been seen in alpha thalassemias. While small deletional mutations such as-3.7 cause ?+-thalassemia, large deletions such as-26.5-20.5 cause ?0-thalassemia. The objective of our study was to determine the profile of deletional and non-deletional ?-globin gene mutations in the Antalya population, Turkey. In present study, the presence of ?-thalassemia mutations were investigated by RDBH (reverse dot blot hybridization) among 250 patients with microcytic anemia and beta globin normal. Some positive and negative cases were confirmed by MLPA (multiplex ligation dependent probe amplification) and at the latest DNA sequencing. Eight different mutations were determined in 112 (44.8%) of patients in our study. The-??3.7 deletion was the most common mutation(73.3%). Others common mutations were the – ?20.5 (13.0%) and –MED (6.5%),--FIL (2.4%), Hb Adana (2.4%). The 97.5 % of total mutations consisted of these five mutations. Three patients with Hb H disease were found related with-? 3.7 /-(?)-20.5 genotype. One patient (2.04%) had the ??? anti-3.7 gene triplication. Two rare mutations, ?2 codon 64 (G>C) (Hb Fontainebleau) and ?2 codon 193 (G>A) (Hb G-Waimanalo), were determined by DNA sequencing firstly in Antalya Province, Turkey. Our results may be valuable to give accurate premarital genetic counseling and to apply classical prenatal and preimplantation genetic diagnosis by the complementary methods such as RDBH, MLPA and DNA sequencing for the screening of alpha thalassemia carriers. © 2021, Yuzuncu Yil Universitesi Tip Fakultesi. All rights reserved.