Spectrum of β-thalassemia mutations in Egypt

Provincial Hemoglobinopathy, DNA Diagnostic Laboratory, McMaster University Medical Centre, Hamilton, Ontario, Canada.
Hemoglobin (Impact Factor: 0.79). 09/1999; 23(3):255-61.
Source: PubMed
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    • "Still, as much of the currently available data have been collected and pooled and the reported mutations and their corresponding frequencies in twelve different countries have been tabulated for comparison (see Table 1). These include Syria [1], Lebanon [2] [3] [4], Jordan [5], Israeli Arabs [6] and Arabs from the Gaza strip [7], Saudi-Arabia [8] [9] [10] [11], Kuwait [12], Bahrain [13], the United Arab Emirates (UAE) [14] [15] [16] [17], Oman [18], Egypt [19] [20] [21] [22] [23], Tunisia [24] [25], and Algeria [26] [27] [28]. "
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    ABSTRACT: The Arab countries encompass a wide region stretching from the Persian Gulf to the Atlantic Ocean. The Arab population is quite heterogeneous and has experienced various invasions and migrations throughout history. β-thalassemia is endemic in all countries of the Arab world. Our review of the molecular basis of β-thalassemia in various Arab countries reveals the presence of 52 mutations, which are mostly of Mediterranean and Asian origin. The distribution of mutations reflects the geographical and historical backgrounds of each region. However, no specific mutation is confined to the Arabs, although some Arab countries do have unique mutations.
    BioMed Research International 02/2001; 1(3):129-132. DOI:10.1155/S1110724301000298 · 2.71 Impact Factor
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    ABSTRACT: The present study attempts to delineate the spectrum of β‐thalassemia (thal) mutations in Tunisia by studying a large population from different parts of the country. A total of 285 unrelated subjects, 190 of whom had β‐thal major, 72 with Hb S/β‐thal, one with Hb C/β‐thal, one with Hb O‐Arab/β‐thal and 21 β‐thal carriers, were studied. The molecular defects were detected in 97.7% of the β‐thalassemic chromosomes (n = 475). Nineteen different β‐thalassemic alleles were identified. Two mutations, namely codon 39 (C→T) and IVS‐I‐110 (G→A) accounted for 70.0% of the studied chromosomes, followed by IVS‐I‐1 (G→A) (4.5%). Five other mutations, frameshift codon (FSC) 44 (–C), codon 30 (G→C), IVS‐I‐2 (T→G), IVS‐II‐745 (C→G), and FSC 6 (–A), are not uncommon in this population, while the remaining 11 mutations, IVS‐I‐5 (G→A), − 30 (T→A), codons 25/26 (+ T), IVS‐I‐6 (T→C), FSC 5 (–CT), IVS‐II‐848 (C→A), FSC 8 (–AA), –87 (C→G), IVS‐I‐5 (G→C), IVS‐II‐1 (G→A) and IVS‐II‐849 (A→C) are quite rare; four of these have not been previously reported in the Tunisian population. Potential origin and spread of these mutations to Tunisia are also discussed.
    Hemoglobin 01/2004; 28(3):177-187. DOI:10.1081/HEM-120040307 · 0.79 Impact Factor
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    ABSTRACT: We determined the spectrum of beta-thalassemia (thal) mutations in 118 affected unrelated patients with different forms of beta-thal. Using a combination of reverse dot-blot analysis, denaturing gradient gel electrophoresis (DGGE), polymerase chain reaction/restriction fragment length polymorphism (PCR/RFLP) and direct nucleotide sequencing, we identified the largest spectrum of beta-thal mutations so far reported in Tunisia, and to the best of our knowledge, within the Mediterranean Basin. A total of 18 distinct alleles were detected at different frequencies, with two alleles [codon 39 (C-->T) and IVS-I-110 (G-->A)] predominating all others. Seven other alleles [frameshift at codon (FSC) 6 (-A), FSC 8 (-AA), codon 30 (G-->C), IVS-I-1 (G-->A), IVS-I-2 (T-->G), IVS-I-6 (T-->C), FSC 44 (-C)] were rare, and nine alleles [-29 (A-->G), IVS-I-2 (T-->C), IVS-I-5 (G-->C), IVS-I-5 (G-->T), IVS-I-116 (T-->G), codon 37 (G-->A), IVS-II-1 (G-->A), IVS-II-745 (G-->C) and IVS-II-849 (A-->C)], albeit described elsewhere, are reported here in Tunisia for the first time. The codon 39 and IVS-I-110 mutations were the two predominant alleles occurring at frequencies of 43.8% and 10.8%, respectively. They are presumably the earliest mutations introduced into this country. The codon 39 allele could have been introduced in Tunisia during the Roman occupation. Similarly, the IVS-I-110 mutation might have been introduced by the Turkish and Phoenician influence. Both gene flow and private mutations may account for the diversity of alleles observed in Tunisia. These data provide the background for implementing prevention programs based on genetic counseling and prenatal diagnosis.
    Hemoglobin 09/2004; 28(3):189-95. DOI:10.1081/HEM-120040305 · 0.79 Impact Factor
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