en Biological Sciences Biological Sciences Original Research: Basic Science in Medicine Original Research: Basic Science in Medicine By application of modern recombinant DNA technology, especially the polymerase chain reaction (PCR)/dot-blot hybridization techniques, we have investigated the molecular basis of β-thalassemia from four different regions of Iran: central, south-east, south and north. In this study, the DNA samples were isolated from patients and for the identification of the mutations, the 6 oligonucleotide probes for the mutations of IVS.1/nt. 110, .lVS.1/nt.6, IVS.1/nt.1 , nonsense codon 39, frameshift codon 8 and IVS. 2/nt.1 were selected with respect to their relative frequency in the neighbouring country, Turkey. Four mutations accounted for76.2% and of these, the most frequent was the nonsense codon 39 mutation, which accounts for 60.3% of the β-thalassemia alleles tested. The remainder, in decreasing order of frequency, wereframeshift codon 8(9.5%), lVS. 1/nt.6 (4.8%) and IVS.1/nt.11O(1.6%). No hybridization was observed with the probes corresponding to the mutations of rvS.I/nt I (0/ A) and rvS.2/nt.1 (0/ A). These results also revealed that the distributions of different types of mutations were different in the four regions. This information and the introduction to the methodology used in this study will facilitate the prenatal diagnosis of the disease in Iran. β-Thalassemia, β-Globin gene mutations. Polymerase chain reaction, Molecular 101 107 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-298-590&slc_lang=en&sid=1 MR NOORI-DALOII 20031947532846006061 20031947532846006061 Yes From the Department of Biochemistry, School of Medicine, Tehran University of Medical Sciences, Tehran N MOAZAMI 20031947532846006062 20031947532846006062 No Department of Biotechnology, Iranian Research Organization for Science And Technology, Tehran M IZADYAR 20031947532846006063 20031947532846006063 No Children s Medical Center, Tehran University of Medical Science, Tehran S FARHANGI 20031947532846006064 20031947532846006064 No Queshm Island Medical Center, Queshm, Islamic Republic of Iran F BEYRAMI JAMAL 20031947532846006065 20031947532846006065 No Department of Biotechnology, Iranian Research Organization for Science And Technology, Tehran A ATALAY 20031947532846006066 20031947532846006066 No the Marmara Research Center, Gebze-Kocaeli, Torkey. LN GEREN 20031947532846006067 20031947532846006067 No the Marmara Research Center, Gebze-Kocaeli, Torkey. L AKAR 20031947532846006068 20031947532846006068 No the Marmara Research Center, Gebze-Kocaeli, Torkey. E ATALAY 20031947532846006069 20031947532846006069 No the Marmara Research Center, Gebze-Kocaeli, Torkey. B CIRAKOGLU 20031947532846006070 20031947532846006070 No the Marmara Research Center, Gebze-Kocaeli, Torkey. E BERMEK 20031947532846006071 20031947532846006071 No the Marmara Research Center, Gebze-Kocaeli, Torkey.