Detection of <i>β</i>-Hemoglobin Gene and Sickle Cell Disorder from Umbilical Cord Blood

Abstract

Sickle cell disease (SCD) is one of the most common hemoglobinopathies, which is caused by the replacement of glutamic acid with valine at the sixth position of the beta-globin amino acid chain which sickling of the entire red blood cells in the homozygous (Hb S/S) condition. There are many analyses and screening procedures were developed to detect sickle cell anemia in the early age of birth, especially from heel prick blood, but in case of developing countries, it would be more acceptable to detect sickle cell disorder using umbilical cord blood just after birth rather than using heel prick blood. In this study, umbilical cord blood (UCB) was used to detect β-hemoglobin gene and sickle cell disorder. Polymerase chain reaction (PCR) based analysis was done using two primers (wild-type and mutant type) to detect this disorder. A total number of 22 samples were enrolled in this experiment for PCR amplification among which nineteen samples were identified by amplification of both 267 bp and 517 bp fragments revealing heterozygous sickle cell trait (Hb A/S), whereas three samples were found to amplify of 517 bp only revealing healthy individuals. The result from PCR analysis was then collaborated with the information of the mothers of each sample to analyze the result more conveniently and found that the mothers of all individuals except the three samples had anemia or mild form of anemia, thus it was expected that the newborn might have anemia trait (Hb A/S) the exception was found in case of sample No. 9 and sample No. 15. Both samples showed the bands on 267 bp and 517 bp thus expressed the sickle cell disease trait although the mothers of these samples were not anemic. However, no samples were recorded having sickle cell anemia (9 Hb S/S). The inherent simplicity and low cost of this PCR based analysis with umbilical cord blood will be considered as an effective tool in future newborn screening in Bangladesh.