Electrophoretic and molecular profile of the hemoglobinopathies in newborns at a reference hospital in Mozambique

Abstract

Hemoglobinopathies are monogenic diseases with a significant impact on public health. It is estimated that 5.2% of the world population has at least one genetic alteration in the genes that code for globins and in Africa, 18.2% of the population have hemoglobinopathies of clinical relevance. Using hemoglobin capillary electrophoresis, we screen newborns from the Central Maputo Hospital in Mozambique for hemoglobinopathies and then used various PCR to genotype-affected newborns. Screening of newborns revealed that 35.8% had hemoglobinopathy traits, with variants running in the position of Hb Bart (33.2%), Hb C (1.7%), Hb D (0.8%), and Hb S (sickle cell) (0.4%). The molecular test identified that 9.9% of the newborns were homozygous for 3.7 kb and/or 4.2 kb deletion genotype and that there may be an uncharacterized deletion of MCS-R located on chromosome 16. This study also confirmed the presence of hemoglobin variants, Hb Maputo and Hb S, through the identification of their defining mutations. No mutations for Hb C were found; thus, we believe that it was a result of a screening error or contamination. This study successfully identified hemoglobinopathies of clinical significance within the Mozambican population, α-thalassemia and hemoglobin S, as well as their associated genotypes. Future research should include samples from other regions of the country and the use of a more comprehensive molecular diagnostic tool. With the confirmation of clinically significant genotypes, the local health system should promote the importance of screening of hemoglobinopathies in Mozambican newborns and adults.