Frequency of Cap+1 Mutation in Beta Thalassemia and its Associated Haematological Features

Abstract

Objective: To study the frequency of Cap+1 mutation and associated hematological parameters in suspected beta thalassemia patients.

Study Design: Analytical cross-sectional study.

Place and Duration of Study: Department of Hematology, Armed Forces Institute of Pathology (AFIP) Rawalpindi from Aug 2017 to Aug 2018.

Methodology: 960 patients suspected to have beta thalassemia were inducted into the study. After detailed history and examination basic hematological parameters (Hemoglobin, Mean Corpuscular Volume, Mean Corpuscular Hemoglobin) were analyzed using automated analyzer (Sysmex XE-5000). Molecular genetic analysis by conventional PCR was carried out for CAP+1 mutation. Genomic DNA purification kit (Gentra system USA) was used for extracting DNA from whole blood in order to study the molecular genetics for Cap+1 mutation. Primers were designed for detection and analysis of normal and mutant DNA.

Results: The frequency of Cap+1 mutation was observed in 3.2 ± 1.7% (31/960) in all suspected cases of beta thalassemia with a normal range of Hemoglobin (12.4 ± 1.1 g/dl), Mean Corpuscular Volume (86.4 ± 2.1fl/red cell) and Mean Corpuscular Hemoglobin (29 ± 1.7pg/cell).

Conclusion: Cap+1 mutation is a silent mutation and its diagnosis remains a challenge because of its normal clinical presentation and normal to mildly deranged basic hematological parameters. Detection of CAP+1 at molecular level has revolutionized the thalassemia prevention program in Pakistan.