Prenatal diagnosis of beta-thalassemia in Southern Punjab, Pakistan

Abstract

Pakistan has a large population of more than 150 million people with an overall carrier frequency of approximately 5.6% for beta-thalassemia. Punjab is the largest province of the country having more than 50% of the population. The state of beta-thalassemia is alarming as consanguinity is very high (>81%) and the literacy rate is low in South Punjab. A thalassemia prevention program is the need of the hour in this part of Pakistan. In this study, we initiated awareness, screening, and characterization of the mutations causing beta-thalassemia as well as a genetic counseling program mainly in the districts of Faisalabad and D.G. Khan to establish prenatal diagnosis, a facility previously unavailable in this region for disease prevention. A total of 248 unrelated transfusion-dependent children and the available members of their families were screened to characterize the mutations and identify the carriers. Genetic counseling was provided to these families and prenatal diagnosis offered. In the samples analyzed, 11 beta-thalassemia mutations and three hemoglobin variants were detected mainly by using the Monoplex and Multiplex ARMS-PCR. First-trimester prenatal diagnosis was carried out through chorionic villus sampling (CVS) in seven pregnancies at risk. As a result of our campaign, 145 carrier couples planning to have more children gave their consent to have retrospective prenatal diagnosis in every pregnancy in future. A cooperative trend and a positive attitude toward the prevention of beta-thalassemia were noticed in the families with affected children and in the general population.