To investigate the molecular basis of β-thalassemia intermedia in Northern Iraq and evaluate its management practices, a total of 74 patients from 51 families were enrolled. The patients were clinically and hematologically reevaluated, and had their β-thalassemia mutations characterized, as well as the number of α-globin genes and Xmn I G γ −158 (C>T) polymorphism studied. Out of 14 β-thalassemia mutations identified, the four most common were IVS-I-6 (T>C) [33.3%], IVS-II-I (G>A) [21.1%], codon 82/83(−G) [10.1%], and codon 8 (−AA) [8.1%]. The most common contributing factors to the less severe phenotype of thalassemia intermedia were found to be the inheritance of mild β-thalassemia alleles and the Xmn I polymorphism, while concomitant α-thalassemia had a limited role. Several complications were documented including: pulmonary hypertension in 20.4%, diabetes mellitus in 1.4%, hypothyroidism in 2.9%, and heart failure in 2.7%, while no documented cases of venous thrombosis were found. Compared to their counterparts in several Mediterranean countries, it appears that our patients were much less frequently transfused and had a lower proportion of patients who were splenectomized, on iron chelation, or hydroxycarbamide therapy. Such practices require further scrutiny to ensure that a better level of care is provided and that growth retardation, skeletal changes, and other complications are prevented or reduced.
Objective: To evaluate the feasibility and effectiveness of a preventive programme for haemoglobinopathies in a single centre in Northeastern Iraq. Methods: Premarital screening, genetic counselling and prenatal diagnosis (PND) were implemented over a 5 year period. Results: Among a total of 108,264 screened individuals (54,132 couples), b-thalassaemia trait, db-thalassaemia trait, and sickle cell trait were diagnosed in 3.98%, 0.11% and 0.07%, respectively. Of 130 at risk couples (2.4/1000), 107 (82%) were available for follow up, with 105 couples (98.1%) proceeding with their marriage after counselling. In the 125 registered pregnancies in the latter couples, PND was performed in 85 (in 80 couples, uptake 76%). Selective termination was chosen in 10 of the 11 pregnancies with an affected fetus. Six affected babies were born among couples who declined PND. At the same time 30 already married couples with at least one thalassaemic child underwent PND, revealing three affected fetuses; all three pregnancies were terminated. Conclusion: The programme revealed that most at risk couples diagnosed by premarital screening chose to proceed with their marriage, with 76% seeking PND followed by selective termination of an affected fetus. A 65% reduction in number of affected births was reported over the 5 year period. This regional programme could serve as a prototype for a national haemoglobinopathy prevention programme.
A random 123 carriers of β-thalassemia (β-thal), identified by the Sulaimaniyah Provincial Premarital Screening Program in northeastern Iraq, were screened for β-thal mutations using multiplex polymerase chain reaction followed by reverse hybridization StripAssay and direct sequencing. A total of 11 different β-thal mutations was identified in the studied samples, of which eight represented 96% of the mutated β-globin genes. These were IVS-II-1 (G>A), IVS-I-110 (G>A), codon 8 (-AA), codons 8/9 (+G), IVS-I-5 (G>C), codon 5 (-CT), IVS-I-6 (T>C) and IVS-I-1 (G>A). Other mutations were less common or sporadic. There were some notable differences in frequencies of various mutations in comparison to other eastern Mediterranean populations, as well as with previous studies of Iraqi Kurds. The latter illustrate the relative heterogeneity of the mutations distributed in Iraq, and the need to screen other areas of the country, to ensure the establishment of an effective prenatal diagnosis program.
Epidemiological studies have revealed that sickle cell disease patients are clustered in two geographical areas in Iraq, one among the Arabs in the extreme south, another among the Kurdish population in the extreme north, where they constitute major health problems. However, no studies have focused on the genotypes responsible for sickle cell disease or the β-globin gene haplotypes associated with it. For the latter purpose, a total of 103 unrelated Kurdish sickle cell disease patients were evaluated by restriction fragment length polymorphism (RFLP) for the sickle cell mutation, followed by multiplex polymerase chain reaction (PCR) and reverse hybridization for β- and α-thalassemia (β- and α-thal) mutations, whenever indicated. Results showed that the most common genotype was sickle cell anemia (68.0%) followed by Hb S/β(0)-thal and Hb S/β(+)-thal at frequencies of 24.2 and 7.8%, respectively. Eight β-thal mutations were associated with the latter two genotypes including: IVS-II-1 (G>A), IVS-I-110 (G>A), codon 8 (-AA), codon 44 (-C), codon 22 (-7 bp), IVS-I-1 (G>A), codon 30 (G>C) and IVS-I-6 (T>C). In Hb SS patients, the -α(3.7) deletion was documented in 10.0% and was the only α-thal mutation detected. Furthermore, 5' β-globin gene cluster haplotyping of 128 β(S) chromosomes revealed that the most common haplotype seen in 69.5% was the Benin haplotype, followed by the Arab-Indian haplotype in 12.5%. These latter findings closely resemble reports from neighboring Turkey, Syria, Jordan, Lebanon and Mediterranean countries, suggesting a possible common origin, but are in contrast to findings from the Eastern Arabian Peninsula and Iran.
In an attempt to determine the spectrum of α-thalassemia (α-thal) mutations in the Kurdish population of Northeastern (NE) Iraq, a total of 101 unrelated adults with unexplained hypochromia and/or microcytosis were enrolled. α-Thalasssemia mutations were characterized by gap polymerase chain reaction (gap-PCR), multiplex PCR (m-PCR) and reverse hybridization and sequencing for both α genes. A total of nine α-thal mutations were characterized including four deletional ones: -α(3.7) (rightward), - -(MED-I), -(α)(20.5), -α(4.2) (leftward) and five nondeletional ones: α(polyA1)α, αα(Adana), α(-5 nt)α, α(CS)α and α(polyA2)α. These determinants were arranged in 12 different genotypes, the most frequent of which were: -α(3.7)/αα, - -(MED-I)/αα, -α(3.7)/-α(3.7), α(polyA1)α/αα, αα(Adana)/αα and -(α)(20.5)/αα. This pattern is similar to that reported in Turkey, western (W) Iran, Cyprus and Greece, and to some extent, different from the pattern observed in the Arabian Peninsula.
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