Title of article :
Identification of Five Common α-Thalassaemia Genotypes Among A Group of Egyptian Neonates by Single Tube PCR
Author/Authors :
RIZK, SAMIA Cairo University - Faculty of Medicine - Department of Clinical Pathology, Egypt , ZAYED, SHAHIRA Cairo University - Faculty of Medicine - Department of Clinical Pathology, Egypt , AZIZ, MONA Cairo University - Faculty of Medicine - Department of Clinical Pathology, Egypt
Abstract :
The alpha thalassaemias are common genetic disorders that arise from reduced synthesis of the alpha globin chains. At present, large scale carrier screening and clinically valuable antenatal detection programs have not been established for the congenital disorder alpha thalassaemia. This study was conducted on 410 umbilical cord blood samples to detect the relative frequency and differentiate between the five common alpha thalassaemia deletional forms, regardless of the break points, among a group of Egyptian neonates using a single tube multiplex-PCR assay. The method proved to be simple, easy and fast as the number of alpha genes present in the subjects were directly determined by the number and intensity of the al and a2 bands normalized with that offi actin (serving as an internal control). A complete blood picture was done for all samples. Among the DNA samples tested, ten cases were discarded due to failure of amplification. Our results showed that 38 samples (9.5%) were identified as carriers of alpha thalassaemia or suffering from Hb H disease. The percentage of the different genotypes detected was: 4.5% alpha thalassaemia 2 heterozygous (-α/αα), 3% alpha thalassaemia 2 homozygous (-α/-α), 1.75% alpha thalassaemia 1 heterozygous (--/αα) and 0.25% Hb H disease (--/-α). No cases of Hb Bart s hydrops fetalis were detected. On comparing the hematological profile of the normal subjects with that of those with gene deletions it was found that alpha thalassaemia carriers had significantly lower Hb levels, Hct%, MCH and MCHC while the MCV did not differ markedly. No statistically significant difference was found between the various genotypes detected regarding their blood indices. From this we can not rely upon blood indices only for detection of alpha thalassaemia and we highlight the importance of molecular diagnosis using this simple single tube PCR assay in diagnosis of alpha thalassaemia carriers.
Keywords :
Thalassaemia , PCR , Neonates
Journal title :
The Medical Journal of Cairo University
Journal title :
The Medical Journal of Cairo University