Factor V Leiden G1691A, Prothrombin G20210A, and MTHFR C677T and A1298C Mutations in Patients With Sickle Cell Disease in Tunisia.

Sickle cell disease is a genetic disorder characterized by a hypercoagulable state. Several complications in this hemoglobinopathy are increased by thrombosis. Factor V Leiden (FVL), prothrombin (PRT) G20210A, and methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C mutations are major inherited risk factors of thrombotic complications. In this study, our aim was to compare the frequencies of these mutations in sickle cell patients with healthy controls. The study population comprised 35 homozygous Hb S (HBB: c.20A>T) patients, 29 compound heterozygous patients [16 Hb S/ß0-thalassemia (ß0-thal), four Hb S/ß+-thal, seven Hb S/Hb C (HBB: c.19G>A) and two Hb S/Hb O-Arab (HBB: c.364G>A)] and 100 healthy subjects. All patients and controls were subjected to laboratory investigations as well as mutation genotyping. Our findings showed a severe anemia with the lowest values of protein S (PS), protein C (PC) and antithrombin (AT) in the homozygous Hb S group compared to Hb S/Hb C and Hb S/ß-thal subjects. No significant difference in FVL genotype between patients and controls was observed, whereas high frequencies of PRT G20210A, MTHFR C677T and MTHFR A1298C mutations in the Hb S patients and a significant association between the MTHFR C677T mutation and Hb S/ß0-thal were found.

Thrombophilic Mutations Among Patients with Sickle Cell Disease.

BACKGROUND: Factor V-Leiden (FVL), Prothrombin (PRT) G20210A, and Methylene Tetrahydro Folate Reductase (MTHFR) C677T and A1298C mutations are major inherited risk factors of thrombotic complications. Our aim in this study was to investigate the prevalence of these mutations among Tunisian sickle cell patients. METHODS: Study subjects comprised 64 patients and 100 healthy controls. FVL, PRT G20210A, and MTHFR genotypes were determined using a reverse dot blot based method. RESULTS: In the patient population studied, the prevalence of FV Leiden was not statistically different from controls while a significant prevalence of heterozygous PRT G20210A mutation among patients (10.93%) was found. An increased frequency of the MTHFR 677 C>T genotype was seen among patients as well as controls. The results showed no significant association between the MTHFR A1298C mutation and sickle cell disease (SCD). However, the prevalence of carrier among studied patients was 15.62% compared to 7% among healthy subjects. CONCLUSIONS: In conclusion, our data suggest a significant association between PRT G20210A and MTHFR C677T and sickle cell disease among Tunisian patients.

Methylenetetrahydrofolate Reductase (MTHFR) (C677T and A1298C) Polymorphisms and Vascular Complications in Patients with Type 2 Diabetes.

OBJECTIVES: To assess whether 2 polymorphisms of the methylenetetrahydrofolate reductase (MTHFR) gene, C677T and A1298C, are risk factors for vascular complications in Tunisian patients with type 2 diabetes mellitus. METHODS: The MTHFR polymorphisms were genotyped, and plasma homocysteine levels were evaluated in 160 Tunisian patients with type 2 diabetes mellitus. RESULTS: Prevalence of the 2 heterozygous polymorphisms of the thermolabile MTHFR gene (CT and AC) was encountered more commonly in patients with diabetes mellitus than in the healthy controls (p<10-3). Subjects with diabetes had significantly higher homocysteine (Hcy) levels than the control subjects; however, there was no statistical difference in plasma Hcy values between carriers of mutant genotypes (CT/TT for C677T and AC/CC for A1298C) and wild types (CC and AA) in patients with diabetes. Retinopathy was found to be a vascular complication in patients with either the 677CT or the 1298(AC+CC) genotype more commonly than in those with the wild-type genotypes (p=0.003; OR=3.2, 95% CI, 1.4 to 7.4; p<10-3; OR=5.9, 95% CI, 2.7 to 13). Only patients who carry the A1298C mutation (AC+CC) are at risk for at least 1 complication (p=0.002). Double heterozygous mutants were at the greatest risk for retinopathy and for suffering at least 1 complication (p<10-3). CONCLUSIONS: Studies involving a larger study population and various ethnic groups are required before ruling out the role of MTHFR gene in type 2 diabetes mellitus and in vascular complications.

Prothrombin G20210A and methylenetetrahydrofolate reductase C677T polymorphisms in peripheral capillary nonperfusion: a case report.

The G20210A mutation in the prothrombin gene is an established risk factor for venous thrombosis. However, there is some controversy as to the role played by this mutation in arterial thrombotic disease. The association of peripheral capillary nonperfusion with prothrombin G20210A mutation has never been reported before. We present the case of 34-year-old man who presented with peripheral capillary nonperfusion. The fundus examination of his right eye revealed an epiretinal membrane, peripheral (mainly temporally) retinal haemorrhages, exudates and microaneurismal alterations of the vascular bed. Fluorescein angiography of his right eye demonstrated an extended area of capillary nonperfusion distal to the microaneurismal lesions. Evaluation revealed mutations of the G20210A prothrombin and MTHFR genes. Screening for hereditary thrombophilia should be considered, regardless of patient age, in patients with peripheral retinal ischemia. The prothrombin G20210A mutation, a genetic risk factor, may be associated with peripheral capillary nonperfusion.

Association of HLA-DR/DQ polymorphism with Alzheimer's disease.

BACKGROUND: Alzheimer's disease (AD) is a complex disorder, resulting from an interaction between environmental and genetic factors. Several studies have addressed the association of AD with major histocompatibility complex (MHC) polymorphisms without arriving at any definite conclusions. The human leukocyte antigen (HLA) region is the key susceptibility locus in many immunological diseases. The aim of this study was to investigate the probable association between HLA-DR/DQ alleles and AD in Tunisian patients. METHODS: HLA-DR/DQ genotyping was performed using polymerase chain reaction sequence-specific primers with 55 AD patients and 100 healthy individuals serving as the control group. RESULTS: AD in Tunisian patients was found to be associated with the following alleles (Pc denotes Bonferroni corrected probability values): HLA-DRB1*15 (Pc < 10-3), DRB1*04 (Pc = 0.03) and DQB1*06 (Pc < 10-3). Two haplotypes found to be associated with the disease were DRB1*1501/DQB1*0602 (Pc < 10-3) and DRB1*0402/DQB1*0302 (Pc = 0.02). CONCLUSIONS: The authors believe this to be the first research linking the haplotypes DRB1*1501/DQB1*0602 and DRB1*04/DQB1*0302 with AD. Larger studies in other populations will be important to support the present findings of the possible susceptible risk of HLA-DR/DQ in AD.

Screening for viral hepatitis C in a young Tunisian population (more than 175,000 recruits).

BACKGROUND: In front of the considerable impact of the viral hepatitis C, the prevention is more than ever a priority, based essentially on the screening. AIM: We realized an epidemiological study in a population of young recruits with the aim of considering prevalence of anti-hepatitis C Virus (anti-HCV) antibodies, describing its epidemiological evolution and establishing a cartography of the viral hepatitis C in Tunisia. METHODS: Epidemiological retrospective study of prevalence was realized from the data of the screening of anti-HCV antibodies from 2003 till 2012 of all the young recruits suggested to be incorporated for the national service or suggested to be recruited as career soldier. The study was exhaustive concerning 175 322 young and healthy male adults aged between 20 and 30 years old, originating from all parts of Tunisia. The screening was realized by third and fourth generation ELISA tests then validated by Immunoblot. RESULTS: The prevalence was 0.11% and the confirmed prevalence was 0.07%. The positive subjects were mainly between 20 and 25 years old (82.32%) and 91.05% were detected within the framework of their incorporations to the national service. The lowest prevalence was 0.07% in 2004, and the highest was 0.17% in 2011, without a significant tendency in the increase or in the decrease during the period of study (r = 0.857 ; p = 0.564). The screening of anti-VHC antibodies had an unequal geographical distribution according to a North-South decreasing gradient. The highest proportions were registered in the North-West (23.23%) and the District of Tunis (22.73%), contrary to the South-East which was weakly affected (3.54%). The governorates with the highest proportions were Tunis (19.19%), Bizerte (11.62%) and Jendouba (8.59%), the governorates of Monastir and Tataouine were weakly affected (0.51%). CONCLUSION: Prevalence of anti-HCV antibodies in the young and male Tunisian population was weak, stable without significant tendency in the increase or in the decrease from 2003 till 2012, characterized by an unequal geographical distribution according to a North-South decreasing gradient.

Association of HLA-DR/DQ polymorphisms with Guillain-Barré syndrome in Tunisian patients.

UNLABELLED: Human leukocyte antigen (HLA) alleles have been implicated in many autoimmune diseases. The aim of this study is to assess whether HLA-DR/DQ alleles confer susceptibility to Guillain-Barré syndrome (GBS) in a Tunisian population. METHODS: The HLA-DR/DQ genotyping was performed using polymerase chain reaction sequence-specific primers (PCR-SSP) in 38 patients with GBS and 100 healthy Tunisian control subjects. RESULTS: GBS in Tunisian patients was found to be associated with the following alleles with these relative patient versus control frequencies (pc denotes Bonferroni corrected probability values): DRB1*13 (23.68% vs. 9.0%; pc=0.01), followed by DRB1*14 (22.36% vs.5.5%; pc<10(-3)). Two haplotypes, DRB1*14/DQB1*05 and DRB1*13/DQB1*03, were found to be associated with susceptibility to GBS. However DRB1*07/DQB1*02 and DRB1*03/DQB1*02 haplotypes were more frequently observed in controls than in patients (11.5% vs.7.9%; pc=0.007 and 23% vs. 5.26%; pc<10(-3) respectively). These haplotypes seem to confer protection against the disease. CONCLUSION: Our data demonstrated a new GBS predisposition associated with HLA-DRB1*14 and DRB1*13. Theses alleles could be predisposing genetic factors for GBS in the Tunisian population.

Thrombophilic risk factors in different types of retinal vein occlusion in Tunisian patients.

BACKGROUND: Retinal vein occlusion (RVO) is the second most common cause of vision loss because of retinal vascular disease. There are 2 types of RVO: branch retinal vein occlusion (BRVO) and central retinal vein occlusion (CRVO). The pathogenesis of RVO is multifactorial. The role of factor V Leiden (FVL) and prothrombin mutations was examined in patients with CRVO and BRVO. METHODS: FVL and prothrombin were investigated by extracting DNA of 88 patients with RVO. Sixteen of the patients were diagnosed with CRVO, 4 with hemispheric retinal vein occlusion, and 68 with BRVO. The genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism. RESULTS: Significant differences were found in the frequencies of the genotypes for both the FVL (G1691A) (P<10(-3), odds ratio [OR]=17.4, confidence interval [CI]=6.20-59) and prothrombin (G20210A) (P=.007, OR=5.11, CI=1.30-29) polymorphisms between RVO patients and healthy controls. Additionally, the frequency of the GA genotype for the G1691A polymorphism was significantly higher among the patients in a subset of BRVO compared with controls (P<10(-3), OR=21.4, CI=7.34-74.2). However, no statistically significant differences were found in the frequencies of the prothrombin G20210A polymorphism between the BRVO group and healthy controls (P=.09, OR=3.13, CI=64-19.9). The frequency of both G1691A and G20210A genotypes among the patients of a CRVO subgroup was significantly higher compared with controls (P<10(-3), OR=11.4, CI=2.94-44.2; P=.007, OR=10.8, CI=2.15-54.1, respectively), suggesting an association between these polymorphisms and CRVO. CONCLUSIONS: Large study would be required to understand completely the contribution of these markers in the risk of all types of RVO.

Association of methylenetetrahydrofolate reductase (A1298C and C677T) polymorphisms with retinal vein occlusion in Tunisian patients.

The role of two polymorphisms C677T and A1298C of the methylenetetrahydrofolate reductase (MTHFR) gene in the etiology of retinal vein occlusion (RVO) has not been adequately clarified. The aim of this study was to examine the prevalence of these polymorphisms among RVO Tunisian patients with and without systemic risk factors. Seventy-two patients with retinal vein occlusion (RVO) were studied. The control group included140 people matched for age, sex, and risk factors. Participants in the study were genotyped for the MTHFR C677T and A1298C polymorphisms. The genotyping was performed by PCR-RFLP. No significant differences were found in the frequencies of the three genotypes (AA, AC, CC) of the MTHFR A1298C polymorphism between RVO patients and healthy controls. However, the prevalence of the group of mutated genotypes (AC+CC) of the missense variant MTHFR A1298C was significantly different between patients and controls (16.67% vs. 6.42%, p=.01). Additionally, the frequency of the CT genotype as well as the group of combined mutated genotypes (CT+TT) for the C677T variant was significantly higher among RVO patients compared with controls (p<10(-3), p<10(-3)). This suggests an association between this polymorphism and RVO. Large study populations would be required to understand more completely the contribution of these markers in the risk of RVO.

Apolipoprotein E genotypes associated with Alzheimer disease and concomitant stroke.

BACKGROUND: The ɛ4 allele of the apolipoprotein E (APOE) gene is a well-characterized genetic risk factor for Alzheimer disease (AD). The association between stroke and a higher risk for AD has also been reported. Our study sought to determine the relationship between the APOE gene and AD and the comorbid risk of stroke. METHODS: The subjects of this study consisted of 48 patients with AD and 48 members of a control group. All subjects were genotyped for APOE. RESULTS: The results clearly show a significant increased risk of AD in carriers of the APOE ε3/ε4 genotype (P = .003, odds ratio [OR] = 4.1) or ε4 allele (P = .001, OR = 4.2). The risk for stroke in AD patients was also increased for carriers of the APOE ε3/ε4 genotype (P = .02, OR = 9.0) and for carriers of the APOE ε4 allele (P = .004, OR = 5.5). CONCLUSIONS: The present study is the first to establish a relationship between APOE ε4 and concomitant AD and stroke in the Tunisian population.

Association of HLA-DR/DQ polymorphisms with schizophrenia in Tunisian patients.

BACKGROUND AND OBJECTIVES: The hypothesis that human leukocyte antigens (HLAs) confer susceptibility to schizophrenic disorders has been tested by studying linkage and association in family samples. Our goal was to evaluate the role of HLA in the risk of developing schizophrenia in a Tunisian population. DESIGN AND SETTINGS: Blood samples for this case-control study were collected from patients of the Department of Psychiatry at the Military Hospital of Tunisia between July 2012 and May 2013. METHODS: A total of 140 patients with schizophrenia were recruited for genetic analysis. Controls included 100 persons matched for age, sex, and risk factors. Participants were tested for HLA class II alleles. HLA-DRB1 and HLA-DQB1 alleles were genotyped using polymerase chain reaction sequence-specific primers. RESULTS: This study indicates that the alleles most responsible for disease susceptibility are DRB1*03 (P < 10-3) and DQB1*02 (P < 10-3) (P denotes probability values). The most protective alleles are DRB1*13 (P=.013) and DQB1*05 (P < 10-3). Further results revealed that DRB1*0301/DQB1*0201(P < 10-3), DRB1*0401/DQB1*0301 (P < 10-3) and DRB1*1101/DQB1*0301 (P < 10-3) are haplotypes most conducive to disease susceptibility. CONCLUSION: The present findings support an association between schizophrenia and the HLA-DR-DQ locus among a Tunisian population. To our knowledge, this is the first study performed to analyze the association of HLA DRB1/DQB1 alleles on schizophrenia susceptibility in Tunisia.

Association of HLA-DR/DQ polymorphism with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) in Tunisian patients.

BACKGROUND AND OBJECTIVE: Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an immune-mediated disorder of the peripheral nervous system (PNS). The aim of this study was to investigate associations between HLA-DR/DQ alleles and CIDP in Tunisian patients. PATIENTS AND METHODS: HLA DR/DQ genotyping was performed using polymerase chain reaction sequence-specific primers (PCR-SSP) with 36 CIDP patients and 100 healthy individuals serving as the control group. RESULTS: CIDP in Tunisian patients was found to be associated with the HLA-DRB1*13 allele (pc=0.03) (where pc denotes the Bonferroni corrected probability value). Moreover, the two haplotypes, DRB1*13/DQB1*06 (22.22% of patients vs. 8.5% of controls, pc=0.017) and DRB1*07/DQB1*03 (13.88% of patients vs. 3% of controls, pc=0.005), were found to confer a susceptibility to CIDP. CONCLUSION: To our knowledge, this is the first study performed to analyze the association of HLA-DRB1/DQB1 alleles on CIDP susceptibility in a Tunisian population.

Association of methylenetetrahydrofolate reductase polymorphisms with susceptibility to Alzheimer's disease.

BACKGROUND: Genetic risk factors play an important role in the pathogenesis of Alzheimer's disease (AD). In this case-control study, we examined the C677T and A1298C polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene and their correlation with this pathology. OBJECTIVE: To verify the association between MTHFR C677T and A1298C polymorphisms and Alzheimer's disease. METHOD: This work was conducted as a case-control study. Cases consisted of thirty-eight patients and 100 individuals without dementia constituted the control group. Genotyping of MTHFR polymorphisms was performed on patients and controls. RESULT: Genetic analyses did not indicate a significant association between the MTHFR C677T mutation and AD (C/T: 63.15% versus 39%, p=0.087). However, the genotype prevalence of the missense variant MTHFR A1298C was significantly different between patients and controls (A/C: 55% versus 7%, p<10(-3)). Our data suggest an association between the MTHFR A1298C mutation and AD; however, the MTHFR C677T mutation did not contribute to susceptibility for AD. CONCLUSION: The MTHFR A1298C polymorphism is a possible risk factor for Alzheimer's disease.

Methylenetetrahydrofolate reductase (C677T and A1298C) polymorphisms, hyperhomocysteinemia, and ischemic stroke in Tunisian patients.

OBJECTIVE: The present study evaluated the role of the methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C gene polymorphisms and correlated these results with plasma homocysteine (Hcy) levels in Tunisian ischemic stroke (IS) patients. METHODS: Overall, 84 patients with IS were included and compared with 100 healthy controls. The most common stroke risk factors were investigated. Fasting plasma Hcy levels were measured. Genotyping of the MTHFR C677T and A1298 polymorphisms was studied by polymerase chain reaction. RESULTS: Aside from tobacco and alcohol use, the other studied factors were significant risk factors for IS. Mean plasma Hcy levels were significantly higher in IS patients than in controls (16.1 ± 8.28 µmol/L versus 8.76 ± 3.48 µmol/L, P < 10(-3)). Significant associations were found with both the MTHFR 677(CT + TT) and 1298 (AC + CC) genotypes in comparison with controls (P < 10(-3)). A significant synergistic interaction was also found with the double heterozygote MTHFR 677CT/1298AC (P < 10(-3)). Homocysteine levels were significantly higher in IS patients with the MTHFR C677T variant (CT and TT genotypes) (P < 10(-3)); however, the difference was not significant with the MTHFR A1298C variant (AC and CC genotypes) (P = .31). CONCLUSION: The MTHFR C677T and A1298 polymorphisms (individually or in concert) and hyperhomocysteinemia represent important risk factors for IS. Elevated Hcy levels were found to be associated with the MTHFR C677T variant; however, no significant association was found with the MTHFR A1298C variant.

Association of methylenetetrahydrofolate reductase A1298C polymorphism but not of C677T with multiple sclerosis in Tunisian patients.

BACKGROUND AND OBJECTIVE: Multiple sclerosis (MS) is a chronic neurological disease characterized by central nervous system (CNS) inflammation and demyelination of nerve axons. The aim of this study was to investigate a possible association between the methylenetetrahydrofolate reductase (MTHFR) gene and multiple sclerosis in Tunisian patients. PATIENTS AND METHODS: The genotyping of two missense variants of the methylenetetrahydrofolate reductase (MTHFR) gene, C677T and A1298C was performed in 80 multiple sclerosis patients and 200 healthy controls. RESULTS: No significant differences were found in the frequency of the MTHFR C677T polymorphism between MS patients and healthy controls. However, the genotype prevalence of the missense variant MTHFR A1298C was significantly different between patients and controls (A/C: 55% versus 7%, p<10(-3); C/C: 13.75% versus 0%, p<10(-3), respectively). CONCLUSION: Although our preliminary findings suggest no association between the MTHFR C677T variants and MS, there is evidence to suggest a significant association between the MTHFR A1298C polymorphisms and MS.

Association of HLA-DR-DQ polymorphisms with diabetes in Tunisian patients.

OBJECTIVE: Type 1 diabetes (T1D) is a polygenic disease whose principal locus is the human leukocytes antigen (HLA) region. The aim of this study was to evaluate HLA DR-DQ alleles and to asses them as risk factors for type 1 diabetes in the Tunisian population. MATERIALS AND METHODS: A total of 119 subjects with diabetes were tested for HLA class II alleles and compared with 292 healthy controls. HLA DRB1 and DQB1 alleles were genotyped using polymerase chain reaction sequence-specific primers (PCR-SSPs). RESULTS: The results revealed that the most susceptible haplotypes are the DRB1(*)03-DQB1(*)02 (pc<10(-3)) and DRB1(*)0401-DQB1(*)0302 (pc=0.001). (pc denotes Bonferroni corrected probability values.) The most protective haplotypes are DRB1(*)11-DQB1(*)03, DRB1(*)07-DQB1(*)02, and DRB1(*)13-DQB1(*)06 (pc=0.0026, pc=0.0065, and pc=0.02 respectively). Our results showed some particularities unique to Tunisians, there was a lack of a significant protective effect of the DRB1(*)15-DQB1(*)06 haplotype that usually is the dominant combination associated with protection in most other populations. CONCLUSION: Tunisian diabetic patients share the most susceptible and protective HLA haplotypes with Caucasians and those in neighbor Mediterranean countries. This is most likely explained by the history and admixture events of Tunisia and North Africa.

Role of methylenetetrahydrofolate reductase A1298C polymorphism in cerebral venous thrombosis.

The association between the methylenetetrahydrofolate reductase (MTHFR) gene and cerebral venous thrombosis (CVT) remains controversial. This study principally investigated the potential role of the MTHFR A1298C variant and CVT. The genotyping of the A1298C variant of the MTHFR gene was performed in 35 CVT patients and 200 healthy controls. The frequency of A1298C genotype among CVT patients was significantly higher compared with controls (P < 10(-3)), suggesting an association between this polymorphism and CVT. To our knowledge, there are no previous reports assessing the correlation between the MTHFR A1298C variant and CVT. Large study populations would be required to understand the contribution of this marker in the risk of CVT.

Lack of association between factor V Leiden and prothrombin G20210A polymorphisms in Tunisian subjects with a history of myocardial infarction.

BACKGROUND: Myocardial infarction is a multifactorial disease. It is provoked by occlusions in the coronary arteries resulting from exposure to multiple risk factors. OBJECTIVE: To study the risk of myocardial infarction associated with the gene polymorphisms of factor V Leiden and factor II (G20210A). MATERIALS AND METHODS: Cases consisted of 100 myocardial infarction patients who were hospitalized in the Principal Military Hospital of Tunis and 200 control subjects with no history of myocardial infarction. RESULTS: The prevalence of the factor V Leiden was higher in myocardial infarction patients (9%) than in control subjects (6%) with an OR=1.55 (95% CI=0.58-4.12), whereas the prevalence of prothrombin G20210A mutation was 3% and 2.5% in the patient and control groups, respectively [OR=1.21 (95% CI=0.22-5.94)]. CONCLUSION: Our results indicate that neither factor V Leiden nor the prothrombin G20210A contributed to the risk factors for myocardial infarction.

Association of HLA-DR/DQ polymorphism with myasthenia gravis in Tunisian patients.

BACKGROUND AND OBJECTIVE: Myasthenia gravis (MG) is an autoimmune disorder of the neuromuscular junction. MG has been shown to be associated with many human leukocyte antigens (HLA) in different populations. The aim of this study was to investigate the probable association between HLA-DR/DQ alleles and MG in Tunisian patients. PATIENTS AND METHODS: HLA DR/DQ genotyping was performed using polymerase chain reaction sequence-specific primers (PCR-SSP) with 48 MG patients and 100 healthy individuals serving as the control group. RESULTS: Myasthenia gravis in Tunisian patients was found to be associated with the following alleles (p(c) denotes Bonferroni corrected probability values): HLA-DRB1*03 (p(c)<10(-3)), DRB1*04 (p(c)=0.005), DQB1*02 (p(c)=0.002) and, DQB1*03 (p(c)=0.007). CONCLUSION: Our data demonstrated a new HLA-MG predisposition with DRB1*04. The DRB1*03, DRB1*04, DQB1*02, and DQB1*03 alleles also could be predisposing genetic factors for MG in the Tunisian population.