Spectrum of Mutations in Beta-Thalassemia in Maharashtrian Population

Abstract

Background: Beta thalassemia is an auto-recessive disorder that shows the most common gene mutation in hemoglobinopathies. The average prevalence of β-thalassemia carriers in India is 3-4%. Nationally, IVS 1-5(G>C) is the single most common mutant allele and represents 54.7% of all β-thalassemia mutations. 

Aim and objectives: To identify the beta-globin gene mutations causing beta-thalassemia (β-thalassemia) in Maharashtrian population.

Material and methods: This prospective observational study was carried out for 18 months in a tertiary health centre. 3ml of blood samples were collected in EDTA vacutainers from patients who were requested for hemoglobinopathy screening. These patients were examined simultaneously for complete blood count (CBC) and peripheral blood smear (PBS). CBC was done with the help of a fully automated hematology analyzer (five-cell part differential cell counter) further screening for hemoglobinopathy was carried out with Bio-rad variant II Beta Thal Short. Deoxyribonucleic acid (DNA) was isolated from beta-thalassemia cases using Gentra Pure gene- KIT. Biotinylated primers were used to amplify the region of interest in the beta-globin gene. The amplicon was used for Reverse Dot Blot (RDB) to study the following common mutations Codon 8/9 (+G), Codon 15 (G– A), IVS 1:5 (G-C), Codon 30 (G-C), Codon 41/42 (-TCTT), IVS 1:1 (G-T), IVS 1:1 (G-A) and 619 base pair (bp) deletion.

Results: The most common mutation found is IVS 1:5 (G-C) (74%) along with Cod 16 and IVS-II which are uncommon in the study population.

Conclusion: The pathogenic beta thalassemia variants, identified during the present study can be employed for the diagnosis, carrier and prenatal screening, and planning therapy of thalassemia.