Abstract
β-Thalassemia (β-thal) is highly prevalent among the Mediterranean populations. In Lebanon, the carrier rate of the disease is estimated to be around 2.0–3.0%. In this retrospective study, we determined the spectrum of β-thal mutations in a total of 170 individuals from a sample of 140 Lebanese, Iraqi and Syrian refugee families in Lebanon, over a period from 2012 to 2018. Twenty-eight different β-globin gene mutations were identified. The most prevalent mutations were IVS-I-110 (G>A) (HBB: c.93-21G>A), IVS-II-1 (G>A) (HBB: c.315+1G>A), IVS-I-6 (T>C) (HBB: c.92+6T>C) and IVS-I-1 (G>A) (HBB: c.92+1G>A), accounting for the majority of mutations found in HBB mutations analysed in 250 alleles. Ten different β-globin gene mutations that were not previously described in Lebanon were identified in our study. These mutations include the IVS-II-848 (C>A) (HBB: c.316–3C>A), codons 9/10 (+T) (HBB: c.30_31insT), codon 15 (–T) (HBB: c.46delT), −86 (C>G) (HBB: c.-136C>G), Cap +22 (G>A) (HBB: c.-29G>A), −28 (A>C) (HBB: c.−78A>C), codon 7 (GAG>TAG) (HBB: c.22G>T), codon 26 (GAG>TAG) (HBB: c.79G>T), codons 41/42 (–TTCT) (HBB: c.126_129delCTTT), and codons 82/83 (–G) (HBB: c.250delG). Of these, six mutations [codons 9/10, codon 15 (–T), −86, codon 7, codon 26, codons 82/83) were identified in Lebanese samples only; one mutation (IVS-II-848) was identified in both Lebanese and Iraqis; and three mutations (Cap +22, −28, codons 41/42) were identified in Iraqi samples only. Further studies will help better delineate the spectrum of β-thal mutations among different ethnic groups, and provide crucial prevention strategies.
Disclosure statement
The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.