Molecular Detection of Some Mutations Associated with Βeta-Thalassaemia in Iraq

Abstract

the study was carried out in period between “1 August 2005 to 30 of December 2006”.Blood samples of 80 clinically thalassaemic patients were collected from three thalassaemiacenters in Iraq, namely: Ibn Albalady central thalassaemia center in Baghdad, and also fromKerbalaa and Al-Qadissya governorates. Blood samples were also collected from 56 apparentlyhealthy individuals to serve as a control group.DNA was isolated from blood and used for molecular detection of seven types of β-thalassaemiamutations (IVS1 nt.1 G--A , IVS1nt.5 G--C, IVS1 nt.6 T--C, IVS1 nt.110 G --A, codon 39 C--T,IVS2 nt.1G--A, and IVS2 nt.745 C--G) using the PCR based technique called ARMS(Amplification Refractory Mutation System).Five out of seven of these diagnosed mutations were reported for the first time in Iraq, and themost frequent β-thalassaemia mutations were codon 39 and IVS1 nt.110 with the proportions(26.76%) and (20.34%), respectively. No IVS2nt.745 was detected within the studied samples.Genotypic distribution of the samples indicated that there is no significant difference (p > 0.05)between the frequency of homozygotes and heterozygotes within patient group, while there is asignificant difference at (P < 0.01) in comparison with the control group.The study of association between the number and the types of mutations revealed that 28(58%) ofpositive cases have single mutation in a homozygous state or heterozygous state whichsignificantly associated at (P < 0.05) with β-thalassaemia mutations, whereas 20(42%) of thesecases have compound mutations. The most frequent association appeared between IVS1 nt.110 andCodon 39 mutations.Finally, mutations within families, pointed to a positive correlation between the types of mutationsin sons or daughters and their fathers and/or mothers; this indicates the accuracy of the ARMStechnique in detection of β-thalassaemia mutations. This conclusion should be taken with cautiondue to the limited number of families.