Updated Molecular Spectrum of β-Thalassemia Mutations in Duhok Province, Northern Iraq: Ethnic Variation and the Impact of Immigration

Immigration impact on genetic epidemiology of thalassemia worldwide is well-recognized. Over the past decade, the Duhok Province of Northern Iraq attracted a large number of immigrants. To assess whether immigration had contributed to changes in the mutation spectrum of β-thalassemia (β-thal) in the region, we recruited 218 registered patients with symptomatic β-thal. The recruited patients included 50 (22.9%) from resettled migrant families. A total of 431 β-thal alleles were fully characterized, with 20 different thalassemia mutations, the most frequent being IVS-II-1 (G>A) (HBB: c.315 + 1G>A), IVS-I-6 (T>C) (HBB: c.92 + 6T>C), codon 5 (-CT) (HBB: c.17_18delCT), IVS-I-110 (G>A) (HBB: c.93-21G>A), codon 44 (-C) (HBB: c.135delC), codon 8 (-AA) (HBB: c.25_26delAA) and IVS-I-1 (G>A) (HBB: c.92 + 1G>A) constituting 72.8% of the total. Some differences in mutation spectrum were observed compared to earlier studies from this same province, the most notable of which were the higher frequencies of IVS-I-110 and codon 8. Interestingly, the highest proportions of alleles related to immigrants were encountered in these two allele groups. Ethnic variation was also documented, so that while Muslim Kurds had IVS-II-1, IVS-I-6, IVS-I-110, codon 5 and codon 44 as their most frequent mutations, the most frequent among Kurdish Yazidis, were codon 5, codon 44, codon 8 and IVS-I-6. These ethnic variations and changes in mutation spectrums are important and should be taken in consideration to ensure effective implementation of the thalassemia preventive program.

Immunophenotypic aberrancies in acute lymphoblastic leukemia from 282 Iraqi patients

INTRODUCTION

The identification of aberrancies in leukemia-associated immunophenotype (LAIP) of acute lymphoblastic leukemia (ALL) is quite important in the assessment of minimal residual disease (MRD). This study, the first from Iraq, aimed to assess the frequency and patterns of LAIP among Iraqi patients with ALL, to establish future strategies for evaluating MRD.

METHODS

A total of 282 newly diagnosed Iraqi ALL cases were analyzed with six-parameter flow cytometry using a panel of 29 monoclonal antibodies.

RESULTS

Immunological subtyping revealed that 85.5% of cases were B-ALL and the remainder T-ALL. LAIP was detected in 97.1% of B-ALL, and in 26.8% of T-ALL. The asynchronous maturation-associated antigen patterns in B-ALL were CD10^strong+ /TdT^dim+ , CD38^dim+ /CD34⁺ , CD10^dim+ /CD34⁺ , CD10^strong /CD20^strong+ , CD20^strong+ /CD34^+, and CD45^dim+ /CD20^strong+ in 84.6%, while the cross-lineage myeloid expression was seen in 81.3% and aberrant T-cell antigen expression in 6.2%. For T-ALL, asynchronous maturation-associated antigen patterns included the following: CD1a⁺ /CD5⁺ /sCD3⁺ and CD34⁺ /sCD3⁺ in 12.2%. Myeloid and B-cell antigen expression were each identified in 7.3% of T-ALL. No significant differences in LAIP were found between children and adults.

CONCLUSION

The high rates and the patterns of LAIP particularly in Iraqi B-ALL patients may allow the development of more cost-effective strategies for MRD monitoring.

The genetic basis of asymptomatic codon 8 frame-shift (HBB:c25_26delAA) β(0) -thalassaemia homozygotes

Two 21-year old dizygotic twin men of Iraqi descent were homozygous for HBB codon 8, deletion of two nucleotides (-AA) frame-shift β(0) -thalassaemia mutation (FSC8; HBB:c25_26delAA). Both were clinically well, had splenomegaly, and were never transfused. They had mild microcytic anaemia (Hb 120-130 g/l) and 98% of their haemoglobin was fetal haemoglobin (HbF). Both were carriers of Hph α-thalassaemia mutation. On the three major HbF quantitative trait loci (QTL), the twins were homozygous for G>A HBG2 Xmn1 site at single nucleotide polymorphism (SNP) rs7482144, homozygous for 3-bp deletion HBS1L-MYB intergenic polymorphism (HMIP) at rs66650371, and heterozygous for the A>C BCL11A intron 2 polymorphism at rs766432. These findings were compared with those found in 22 other FSC8 homozygote patients: four presented with thalassaemia intermedia phenotype, and 18 were transfusion dependent. The inheritance of homozygosity for HMIP 3-bp deletion at rs66650371 and heterozygosity for Hph α-thalassaemia mutation was found in the twins and not found in any of the other 22 patients. Further studies are needed to uncover likely additional genetic variants that could contribute to the exceptionally high HbF levels and mild phenotype in these twins.

Predictors of Red Cell Alloimmunization in Kurdish Multi Transfused Patients with Hemoglobinopathies in Iraq

Hemoglobinopathies are significant health problems in Iraq, including its Northern Kurdistan region. One of the essential components of management of these disorders is regular lifelong blood transfusions. The latter is associated with several complications including red cell alloimmunization. No study has looked at the frequency of alloimmunization and its associations in the country. To address the latter issue, 401 multi transfused patients [311 with β-thalassemia (β-thal) syndrome and 90 with sickle cell disease], registered at a large thalassemia care center in Iraqi Kurdistan had their records reviewed, and their sera tested for atypical antibodies using screening and extended red cell panels. Red cell alloimmunization was detected in 18 patients (4.5%) with a total of 20 alloantibodies, while no autoantibodies were detected. The most frequent alloantibody was anti-E, followed by anti-D, anti-K, anti-C(w), anti-C, anti-c and anti-Le(a). Ethnicity was an important predictor of alloimmunization, while age at start of transfusion (>2 vs. ≤2 years) (p = 0.005), Rhesus D (RhD) negative status (p = 0.0017) and history of previous transfusion reactions (p = 0.007) showed a statistically significant higher rate of alloimmunization. However, patients' age, gender, number of units transfused, underlying diagnosis and splenectomy were not significantly associated with alloimmunization. Based on our observations, measures to reduce alloimmunization rates may include extended matching for Rhesus and Kell antigens and early initiation of blood transfusions.

The Contributions of Thrombophilic Mutations to Genetic Susceptibility to Deep Venous Thrombosis in Iraqi Patients

BACKGROUND AND AIMS

There is a paucity of data on the contribution of various thrombophilic mutations to the development of venous thrombosis in Iraqi patients. Therefore we designed a study to assess the frequencies of known thrombophilic mutations in this population.

METHODS

100 consecutive Iraqi patients with color Doppler confirmed deep venous thrombosis of the lower extremities and 100 age- and sex-matched healthy controls were enrolled in the study. Their DNAs were tested by multiplex polymerase chain reaction (PCR) followed by reverse hybridization for factor V Leiden (FVL), the prothrombin (PT) G20210A SNP, and the MTHFR C677T SNP. The factor V A4070G mutation was assessed by restriction fragment length polymorphism-PCR.

RESULTS

The prevalence of FVL was 13% in patients versus 2% in controls (odd ratios [OR] 7.3; p=0.007). Patients with recurrent thrombosis also had a significantly higher frequency of Factor V Leiden (OR 8.4, p=0.0007). The prothrombin G20210A, SNP, the factor V A4070G SNP, and the MTHFR 677 TT genotypes were present among patients at 5%, 9%, and 11%, respectively, and among controls at 2%, 6%, and 6%; none of these single mutation prevalence differences were significant. Interestingly, however, when these polymorphisms were studied in aggregate we found that 24% of patients had two or more thrombophilic alleles, compared to only 8% of the controls (OR 3.6; p=0.002). This subgroup included significantly more patients with proximal (p=0.007) and recurrent thrombosis (p=0.012), as well as younger patients (≤40 years) (p=0.026).

CONCLUSION

Two or more thrombophilic alleles, as well as FVL on its own, were both significantly associated with an increased risk of venous thrombosis and recurrence in Iraqi patients. Single thrombophilic mutations on their own were not associated with an increased risk.

Molecular Basis of β-Thalassemia Intermedia in Erbil Province of Iraqi Kurdistan

β-Thalassemia intermedia (β-TI) is a clinical term describing a range of clinical phenotypes that are intermediate in severity between the carrier state and β-thalassemia major (β-TM). To characterize the molecular basis of β-TI in Erbil Province, Northern Iraq, 83 unrelated patients were investigated. Detection of β-globin gene mutations was carried out by reverse hybridization assay and direct gene sequencing. All patients were screened for the XmnI polymorphism by direct sequencing of HBG2 ((G)γ promoter gene). Detection of α-globin gene deletions and triplication was carried out using the reverse hybridization assay. Four main molecular patterns were identified in association with the β-TI phenotype, namely: β(+)/β(+) (38.5%), β(+)/β(0) (21.6%), β(0)/β(0) (31.3%), and β(0)/wild type (8.4%). IVS-I-6 (T > C) was the most frequently encountered mutation (55 alleles, 34.6%), followed by IVS-II-1 (G > A) and codon 8 (-AA); furthermore, we report for the first time from Iraq two β(+) mutations, -87 (C > G) and 5' untranslated region (5'UTR) +22 (G > A). The XmnI polymorphism was detected in 47.0% of patients, mainly in association with the β(0)/β(0) genotype. The α-globin gene deletions were encountered in four cases, including one case with (- -(FIL)) double gene deletion, a report that is the first from our country. The α-globin gene triplication was detected in five of the seven heterozygous β-thalassemia (β-thal) patients. Similar to other Mediterranean countries, inheritance of mild β-globin mutations was the main molecular pattern underlying β-TI in our patients followed by the ameliorating effect of the XmnI polymorphism.

Genetic Modifiers in β-Thalassemia Intermedia: A Study on 102 Iraqi Arab Patients

To determine the molecular basis of β-thalassemia intermedia (TI) and the contribution of the three hemoglobin F (HbF) quantitative trait loci (QTLs) on chromosomes 11, 2, and 6 to the milder phenotype, a total of 102 Iraqi Arab patients with TI were studied. The β and α genotypes as well as HBG2 g. 158 C>T (rs7482144), BCL11A (rs1427407 and rs10189857), and HBS1L-MYB (rs28384513 and rs9399137) by multiplex polymerase chain reaction and reverse hybridization were studied. A total of 21 different β-thalassemia mutations arranged in 35 different genotypes were identified. The genotypes encompassed β(+)/β(+) mutations in 33 cases, β(+)/β(0) in 17 cases, β(0)/β(0) in 47 cases, β(0)/wild type in 3 and β(0)/Hb E in 2 cases. The most common was IVS-II-1 (G>A)/IVS-II-1 (G>A), followed by IVS-I-6 (T>C)/IVS-I-6 (T>C) and IVS-I-110 (G>A)/IVS-I-110 (G>A), in 31.4%, 17.6%, and 6.9%, respectively. Alpha-thalassemia mutations were found in 15.2% of those homozygous for the β-mutations, while α gene triplication was identified in all three heterozygotes. Of the five QTLs tested, only rs7482144 and rs10189857 were significantly associated with β(0)/β(0) when compared to β(+)/β(+), with odds ratios of 6.4 (95% confidence interval [CI] 2.9-14.0) and 3.2 (95% CI 1.2-8.6), respectively. In conclusion, this study has demonstrated that among Iraqi patients with thal intermedia, the main contributors to the milder phenotype were β(+) alleles, XmnI polymorphism, and BCL11A (rs10189857), while other QTLs on chromosomes 2 and 6, as well as alpha-thalassemia, were not significantly relevant.

Premarital screening for hemoglobinopathies: experience of a single center in Kurdistan, Iraq

BACKGROUND

A program for the prevention of major hemoglobinopathies was initiated in 2008 in the Kurdistan region of Iraq. This study reports on the achievements and challenges of the program.

METHODS

A total of 102,554 individuals (51,277 couples) visiting a premarital center between 2008 and 2012 were screened for carrier status of hemoglobinopathies, and at-risk couples were counseled.

RESULTS

A total of 223 (4.3/1,000) couples were identified and counseled as high-risk couples. Available data on 198 high-risk couples indicated that 90.4% proceeded with their marriage plans, and 15% of these married couples decided to have prenatal diagnosis (PND) in subsequent pregnancies with the identification of 8 affected fetuses; all were terminated as chosen by the parents. Thirty affected births were recorded among the high-risk couples. The premarital program managed to reduce the affected birth rate of major hemoglobinopathies by 21.1%. Of the 136 affected babies born during the study period, 77.9% were born to couples married prior to the start of the program, while 22.1% were born to couples identified as having a high risk. The main reason for not taking the option of PND was unaffordable costs.

CONCLUSIONS

Financial support would have increased opting for PND by high-risk couples. Further reduction in affected birth rates could be achieved by including parallel antenatal screening programs to cover those married before the initiation of the premarital program and improving the public health education and counseling programs.

Activated protein C resistance and antiphospholipid antibodies in recurrent fetal loss: experience of a single referral center in northern iraq

The current study was initiated to determine the prevalence of activated protein C (APC) resistance, factor V Leiden and antiphospholipid antibodies (APA) in Iraqi women with recurrent fetal loss (RFL), and evaluate the outcome of intervention in those with such states. For this purpose a total of 103 Iraqi women referred to a major teaching hospital in Northern Iraq with two or more consecutive fetal losses, as well as 100 age matched women with no history of fetal loss and at least one live birth were enrolled. After appropriate clinical evaluation, the enrolled subjects were tested for APA as well as APC resistance. Subjects who were APC resistant were further tested for factor V Leiden mutation using a polymerase chain reaction and reverse hybridization. Patients with documented APA and/or with APC resistance, were put on low dose aspirin with or without low molecular weight heparin during pregnancy, and followed for a minimum of 5 years. The results revealed that among patients' group, APA were detected in 19.4 % compared to 1.0 % of the controls (OR 23.9, p = 0.00005). On the other hand, APC resistance was documented in 9.7 % compared to 1.0 % of the controls (OR 10.6, p = 0.01). Factor V Leiden was detected in 3.9 % of patients and 1 % of the controls (p = 0.38). Among 17 patients with APA available for follow up, there were 24 pregnancies, 18 of which ended with live births (75 %). While among the ten patients who had factor V Leiden or were APC resistant non-carriers, there were 13 pregnancies, 12 ended with live births (92.3 %). In conclusion, this study has demonstrated that among the enrolled Iraqi women, APA and APCR and not factor V Leiden were significantly associated with RFL, and that treatment with aspirin (with or without low molecular weight heparin) had lead to live births in 80.6 % of pregnancies.

Response to tyrosine kinase inhibitors in chronic myeloid leukemia: experience from a west Asian developing country

Tyrosine Kinase inhibitors (TKIs) have dramatically changed the prospects for patients with chronic myeloid leukemia (CML); however, information on CML and response to TKIs from Asia are limited, particularly from West Asia, including Iraq. To address the latter issue we evaluated and monitored a cohort of 108 Iraqi patients diagnosed as chronic phase-CML, enrolled in a government-sponsored national program. The patients were all treated initially by imatinib mesylate. Ninety-two percent of patients had a complete hematological response, 38% had a major molecular response, while 79% had a major cytogenetic response after a median follow-up of 35.7 months. The 3-year Event-Free, Progression-Free, and Overall survival rates were 79.6, 87 and 98.1%, respectively. A total of 26 patients (24.1%) were shifted to an alternative TKI (Nilotinib). After one year of therapy in seventeen of the latter patients, 24% had major molecular response. In conclusion, our results compare favorably with those reported from the West and some Asian countries, and have demonstrated the importance of molecular as well as cytogenetic monitoring, and confirmed the relative success of the national CML program in our country.

Hepatitis C virus genotypes among multiply transfused hemoglobinopathy patients from Northern Iraq

Background and Aim:

Owing to the scarcity of data on hepatitis C virus (HCV) genotypes in Iraq and due to their epidemiological as well as therapy implications, this study was initiated aiming at determining these genotypes in Northern Iraq.

Materials and Methods:

A total of 70 HCV antibody positive multi transfused patients with hemoglobinopathies, who had detectable HCV ribonucleic acid, were recruited for genotyping using genotype-specific nested polymerase chain reaction.

Results:

The most frequent genotype detected was genotype 4 (52.9%) followed by 3a (17.1%), 1b (12.9%) and 1a (1.4%), while mixed genotypes (4 with either 3a or 1b) were detected in 7.1%.

Conclusion:

The predominance of genotype 4 is similar to other studies from surrounding Eastern Mediterranean Arab countries and to the only earlier study from central Iraq, however the significant high proportion of 3a and scarcity of 1a, are in contrast to the latter study and may be explainable by the differing population interactions in this part of Iraq. This study complements previous studies from Eastern Mediterranean region and demonstrates relative heterogeneity of HCV genotype distribution within Iraq and should trigger further studies in other parts of the country.

Molecular Characterization of G6PD Deficient Variants in Nineveh Province, Northwestern Iraq

Glucose-6-phosphate dehydrogenase (G6PD) deficiency considered to be the commonest inherited enzymopathies disorders worldwide including Iraq. Studies have addressed its prevalence and molecular characterization in several parts of the country, but no data were available from Nineveh province, northwestern-Iraq regarding molecular basis of this inherited enzymopathy. To determine the molecular basis of G6PD deficient variants in Nineveh province. A total of 61 G6PD deficient male individuals from Nineveh province were enrolled in this study. DNA from all enrolled individuals were extracted and analyzed for four deficient molecular variants using a polymerase chain reaction-restriction fragment polymorphism method. These deficient variants were G6PD-Mediterranean (563 C→T), G6PD-Chatham (1003 G→A), G6PD-A-(202 G→A) and G6PD-Cosenza (1376 G→C). Also enrolled individuals were screened for silent 1311 (C→T) mutation. It was found that 46 (75.41 %) were G6PD-Mediterranean, 1(1.64 %) were G6PD-Chatham, another 1(1.64 %) were G6PD-A-, and 13 (21.31 %) were remained uncharacterized. Also all G6PD-Mediterranean as well as one uncharacterized individuals were carriers of silent 1311 (C→T) mutation. This study documented that G6PD-Mediterranean constitute the bulk of G6PD deficient variants in this province and G6PD-Chatham and A- were encountered less frequently. Also that silent 1311 (C→T) mutation were common among G6PD-Mediterranean deficient variants individuals.

The first five years of a preventive programme for haemoglobinopathies in Northeastern Iraq

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), β-thalassaemia trait, δβ-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.

Epidemiological profile of common haemoglobinopathies in Arab countries

Haemoglobinopathies including the thalassemias and sickle cell disease are known to be prevalent inherited disorders in most Arab countries with varying prevalence rates and molecular characterisation. β-thalassemia is encountered in polymorphic frequencies in almost all Arab countries with carrier rates of 1-11 % and a varying number of mutations. The most widespread mutation in Lebanon, Egypt, Syria, Jordan, Tunisia and Algeria is the IVS-I-110 (G>A). In the Eastern Arabian Peninsula, the Asian Indian mutations (IVS-I-5 (G>C), codons 8/9 (+G) and IVS-I (-25 bp del)) are more common. The α-thalassemias are encountered in the majority of Arab countries in frequencies ranging from 1 to 58 % with the highest frequencies reported from Gulf countries. The (-α(3.7)) mutation is the most frequent followed by the non-deletional α2 polyadenylation signal mutation (AATAAA>AATAAG) and the α2 IVS1 5-bp deletion. The rates of sickle cell trait in Arab countries range from 0.3 to 30 %, with the Benin, the Arab-Indian and the Bantu haplotypes constituting the bulk of the haplotypes, leading to two major phenotypes; a mild one associated with the Arab-Indian and a severe one with the Benin and Bantu haplotypes. Public health approaches targeting prevention of haemoglobinopathies in Arab countries include newborn screening for sickle cell disease, and premarital screening for carriers of β-thalassemia and sickle cell disease. These services are still patchy and inadequate in many Arab countries recommending the upgrade of these services with strengthening of the education and training of health care providers and raising public awareness on the feasibility of prevention and care for haemoglobinopathies.

The spectrum of α-thalassemia mutations in the Kurdish population of Northeastern Iraq

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.

β-Thalassemia mutations in the Kurdish population of northeastern Iraq

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.

β-Thalassemia Mutations among Transfusion-Dependent Thalassemia Major Patients in Northern Iraq

Molecular defects responsible for β-thalassemias (thal) were investigated among 254 chromosomes from 127 transfusion-dependent unrelated thalassemic patients from two provinces in Northern Iraq. Among fourteen identified mutations, the seven most common found in 88.2% of the thal chromosomes were: IVS-II-1 (G → A), IVS-I-1 (G → A), codon 8 (−AA), codon 39 (G → T), codon 8/9 (+G), codon 44 (−C), and codon 5 (−CT). There were some notable differences in frequencies of various mutations in comparison to other Eastern Mediterranean populations, as well as between the two provinces studied. The latter illustrates the relative heterogeneity of the mutations distribution in Iraq, and the need to screen other areas of the country, to ensure establishing an effective prenatal program.

Homozygosity for the Mediterranean a-thalassemic deletion (hemoglobin Barts hydrops fetalis)

Hemoglobin Barts hydrops fetalis syndrome is the most severe and generally fatal clinical phenotype of alpha-thalassemia. We diagnosed a fetus at 23-weeks gestation with having hydrops fetalis, by ultrasound. At 32 weeks, intrauterine death was detected. Molecular studies revealed that the fetus had the hemoglobin Barts hydrops fetalis syndrome due to homozygosity for the Mediterranean alpha-thalassemia deletion. This clinical phenotype is generally rare in the Eastern Mediterranean, and this is the first report of this syndrome from Iraq. Techniques for molecular characterization became available only very recently in this country, in a diagnostic setting. Thus, the detection of further cases might be expected in future.

Methylenetetrahydrofolate reductase C677T polymorphism in Iraqi patients with ischemic stroke

BACKGROUND

Data are conflicting concerning the association between ischemic stroke and methylenetetrahydrofolate reductase (MTHFR) C677T mutation. Studies addressing this matter in developing countries are limited.

AIM

This study was undertaken to evaluate MTHFR C677T gene polymorphism as a possible risk factor in patients with ischemic stroke in Iraq.

SETTINGS AND DESIGN

A case-control study in a major teaching hospital in Northern Iraq.

MATERIALS AND METHODS

Study population included 70 patients with ischemic stroke diagnosed by computed tomography (CT) or magnetic resonance imaging (MRI) and 50 controls matched by age and sex. All the patients and controls had detailed neurologic examination and blood sugar, lipid profile, total homocysteine, as well as, MTHFR gene analysis. The MTHFR C677T mutation status was detected in the amplified products using reverse hybridization to specific mutant and wild oligonucleotide probes by a colorimetric microwell plate method.

STATISTICAL ANALYSIS

Mann-Whitney U test and Chi-square tests were used to find the significance.

RESULTS

The median age of the patients was 60 years and 54% were males. The MTHFR C677T gene analysis detected TT genotype in 20% of patients and in 6% of controls and CC genotype in 37% of the patients and in 54% of the controls. The calculated risk of ischemic stroke in the subjects with TT genotype was 4.85 times more than the subjects with CC genotype (P = 0.03). Serum homocysteine level was significantly higher in the patients than the controls (P = 0.02). The serum homocysteine levels were significantly higher in those with TT and CT genotypes when compared to those with CC genotype (P < 0.001 and P = 0.04, respectively).

CONCLUSION

In the Iraq population studied MTHFR C677T TT genotype was a significant risk factor for ischemic stroke and it was related to the increased total homocysteine levels and the risk for ischemic stroke was graded with increasing MTHFR 677T allele dose.

Molecular characterization of alpha-thalassemia in the Dohuk region of Iraq

The molecular basis of alpha-thalassemia (alpha-thal) has been addressed by several studies from the eastern Mediterranean region, but not from Iraq. To address this issue, we studied 51 individuals with unexplained hypochromia and/or microcytosis, as well as nine patients with documented Hb H disease from the Dohuk region in northern Iraq. We used multiplex gap-polymerase chain reaction (gap-PCR), reverse hybridization, and sequencing for this purpose. It was found that the most common genotypes in those with unexplained hypochromia and/or microcytosis were -alpha(3.7)/alpha alpha, followed by - -(MED-I)/alpha alpha, then -alpha(3.7)/-alpha (3.7), respectively, detected in 84.3% of the above individuals. Other genotypes identified sporadically were -alpha(4.2)/alpha alpha, alpha(poly A1)alpha/alpha alpha (AATAAA>AATAAG), alpha(Adana)alpha/alpha alpha [Hb Adana, codon 59 (Gly-->Asp) or HBA1:c.179G>A], and alpha(Evanston)alpha/alpha alpha [Hb Evanston, codon 14 (Trp-->Arg) or HBA1:c.43 T>C]. Three cases (5.88%) remained uncharacterized even after sequencing. All nine Hb H cases carried the -alpha(3.7)/- -(MED-I) genotype. Such findings are rather different from those in other eastern Mediterranean populations, particularly with relevance to an Hb H molecular basis.

Molecular characterization of beta-thalassemia in the Dohuk region of Iraq

beta-Thalassemia (thal) is an important health problem in the Dohuk region of northern Iraq because of its high carrier rate and the frequency of consanguineous marriages. Thus, the need to establish an effective preventative program is paramount. As part of this effort, we initiated this study to determine the molecular basis of this disorder in the region. For the latter purpose, either parent of 104 registered beta-thal major/intermedia patients had their full blood counts, hemoglobin (Hb) electrophoresis, Hb A2 and Hb F quantitation performed. Their DNA was extracted, amplified and reverse hybridized to specific oligonucleotide probes to detect 20 beta-thal mutations. The testing detected 12 beta-thalassemic mutations. The eight most frequent were: IVS-II-1 (G-->A), codon 44 (-C), codon 5 (-CT), IVS-I-1 (G-->A), codon 39 (C-->T), IVS-I-6 (T-->C), codons 8/9 (+G) and IVS-I-5 (G-->C). These mutations accounted for 81.7% of the thalassemic defects in the studied individuals. The less frequent mutations were: codon 8 (-AA), IVS-I-110 (G-->A), codon 30 (G-->C) and codon 22 (-7 bp), and the beta-thalassemic defects remained uncharacterized in 11.5% of cases. This is the first study of beta-thal mutations from Iraq, and shows a frequency of thalassemic defects different from those reported in surrounding countries. It provides a foundation for prenatal genetic testing that will be part of a thalassemia prevention program in the Dohuk region.