Significance of Molecular Analysis in a Population Screening Program for Identification of Silent Beta Thalassemia Carriers in a Country with High Disease Prevalence

Abstract

Objective:  The objective of this study is to establish the importance of molecular analysis in such individuals and its significance in a population screening program.

Methodology: This descriptive cross-sectional study was conducted by the Punjab Thalassemia Prevention Project during a period of 1 year from July 2020 to June 2021. A total of 67 individuals suspected to be silent Beta Thalassemia carriers were tested by the multiplex amplification refractory mutation system-Polymerase Chain Reaction to identify underlying mutations. Independent samples T-test was used to compare the RBC indices and HbA2 values of subjects with and without underlying mutations taking P value <0.05 as statistically significant.

Results: Of the individuals tested, 73% (n=49) had underlying Beta Thalassemia mutations. CAP+1 (n=30, 61%) was the most common mutation identified followed by IVS1-5 (n=12, 25%). Subjects with a mutation displayed a significantly lower mean corpuscular volume and mean corpuscular haemoglobin than those without mutation (P = 0.002 and 0.003 respectively). The mean HbA2 in the subjects with mutation was 3.4% vs mean of 3.2% for those without an underlying mutation (P = 0.011).The mean MCV and MCH of CAP+1 mutation was higher when compared to the other mutations identified.

Conclusions: Molecular analysis should be offered to all those individuals who have borderline HbA2, carrier spouse and/or suggestive family history for identification of silent carriers and effective disease prevention.