Risk Factor For Multiple Sclerosis Research Articles

Waterpipe Tobacco Smoking and Other Multiple Sclerosis Environmental Risk Factors

Introduction: There are a number of well-established risk factors for multiple sclerosis (MS). Other factors, however, showed conflicting or inconsistent results. Here, we examine some factors that are unique to or more practiced in Saudi Arabia (SA) and the Arab region such as waterpipe tobacco smoking (WTS), face veiling, raw milk (RM) and camel milk (CM) consumption, and tuberculosis (TB) infection in addition to other traditional factors. Methods: This is a sex- and age-matched case-control study in which we used a structured questionnaire to examine the relation between a number of factors and exposures and the risk of MS. Three hundred MS patients and 601 controls were included. Data were analyzed across different statistical models using logistic regression adjusting for age, sex, marital status, duration of breastfeeding, age first joining school, coffee consumption, and face exposure. Results: Cigarette smoking (OR = 1.79, [95% CI: 1.01–3.17], p = 0.047), WTS (OR = 2.25, [95% CI: 1.21–4.15], p = 0.010), and CM consumption (OR = 2.50, [95% CI: 1.20–5.21], p = 0.014) increased the risk of MS, while performing hajj (OR = 0.47, [95% CI: 0.34–0.67], p = 0.001), TB infection (OR = 0.29, [95% CI: 0.11–0.78], p = 0.015), face veiling (OR = 0.32, [95% CI: 0.23–0.47], p = 0.001), and coffee consumption (OR = 0.67, [95% CI: 0.49–0.89], p = 0.008) appeared to be associated with decreased risk. No association was found between fast food, processed meat, soft drinks, animal milk (other than camel), or RM consumption and the risk of MS. Conclusion: The results of this case-control study confirm that different means of tobacco smoking are associated with increased risk of MS. It also sheds more light on the complex association between infections and MS.

Air pollution is a risk factor for multiple sclerosis – No

Air pollution is a risk factor for multiple sclerosis – No

Air pollution is a risk factor for multiple sclerosis – Commentary

Air pollution is a risk factor for multiple sclerosis – Commentary

Air pollution is a risk factor for multiple sclerosis – Yes

Air pollution is a risk factor for multiple sclerosis – Yes

Impact of Vitamin D Supplementation on Multiple Sclerosis.

Multiple sclerosis (MS) is an autoimmune disease affecting a large number of people every year. The exact causal factor for this disease is unclear, but it commonly affects middle-aged women, with known triggers like stress, childbirth, infections, poor diet, lack of sleep, etc.Many epidemiological studies have indicated that various genetic abnormalities are also critical drivers of the onset of MS. The major risk factors of MS identified include hypovitaminosis D while environmental protective factors include allele HLA DRB1 1501, obesity, Epstein-Barr virus infection, sexual hormones, and smoking.Our article explores the correlation between the deficiency of vitamin D and the onset and progression of MS. The study uses a systematic review methodology by researching and reviewing scholarly articles exploring the topic. We conducted online searches of literature on Google Scholar and PubMed using the keywords "vitamin D deficiency" and "multiple sclerosis" and accessed the relevant secondary literature sources for review. The variables under study included vitamin D insufficiency as the dependent variable while MS was the independent variable. Causal variables included environmental, genetic, and protective factors.We hypothesized that there is indeed a correlation between vitamin D deficiency and MS. The findings from our review indicate a strong correlation between the insufficiency of vitamin D and the onset and progression of MS. These results are essential in devising interventions to accomplish primary and secondary prevention of MS, as well as integrating vitamin D supplementation in current treatment protocols for MS.

Experiences of and attitudes to lifestyle modification for the management of multiple sclerosis: A qualitative analysis of free-text survey data.

BackgroundGrowing evidence suggests a role of lifestyle modification in improved health outcomes for people with multiple sclerosis (pwMS); however, perspectives of pwMS who engage in lifestyle modification are lacking.ObjectiveWe explored perspectives of pwMS regarding the modification of lifestyle‐related risk factors in multiple sclerosis (MS) for disease management to understand attitudes to and experiences of lifestyle modification as part of self‐management from a patient perspective.DesignParticipants were ≥18 years and English speaking who responded to a free‐text open‐ended question in the Health Outcomes and Lifestyle In a Sample of pwMS (HOLISM), an international online survey. Responses were analysed utilizing inductive thematic analysis.ResultsUnder the exploration of lifestyle modification, themes describing the experiences and attitudes of participants included practical challenges and physical and psychological barriers, enablers of change and experienced outcomes. Although participants reported some practical and psychological challenges to adoption and maintenance of lifestyle behaviours, many expressed an ability to gain control of MS through engagement with lifestyle behaviours and the development of hope and optimism that accompanied this sense of control, at times leading to a sense of personal transformation.ConclusionFindings highlight the challenges experienced by pwMS in adopting lifestyle modifications for disease management as well as the positive benefits from following healthy lifestyle behaviours. Our findings may form the basis of more focussed qualitative explorations of the experiences and outcomes of lifestyle modification in MS in the future.Patient ContributionConsenting pwMS completed a survey capturing data on demographics, clinical course, lifestyle behaviours and health outcomes.

Improving smoking cessation support for people with multiple sclerosis: A qualitative analysis of clinicians’ views and current practice

Introduction Smoking is a key modifiable risk factor in multiple sclerosis (MS). MS healthcare providers have a central role informing people of the deleterious effects of smoking on MS progression and promote smoking cessation, yet there is limited information about smoking cessation and support provided by these providers. This study aimed to gain an understanding of MS healthcare providers current practices, barriers and facilitators related to providing smoking cessation support for people with MS.Methods A total of 13 MS nurses and 6 neurologists working in public and private MS clinics across Australia were recruited through professional networks and MS organisations. Telephone interviews were conducted, transcribed and evaluated using framework analysis.Results MS nurses and neurologists reported that they routinely assess smoking status of people with MS at initial appointments and less regularly also at follow-up appointments. Clinicians considered it important to provide information about smoking impact on MS health outcomes and advise to cease smoking, but the content and delivery varies. Beyond this, some clinicians offer referral for smoking cessation support, while others stated this was not their responsibility, especially in light of competing priorities. Many were unsure about referral pathways and options, requiring more information, training and resources.Conclusion Results of this research indicate that there is potential to improve support for MS clinicians to promote smoking cessation among people with MS. Smoking cessation support may include tailored patient resources, clinician training and stronger collaboration with smoking cessation service providers.

Results of analytic and epidemiologic research of external risk factors for multiple sclerosis among moscow population

Results of epidemiologic reseach of environmental risс factors for multiple sclerosis among Moscow population are given. It was shown, that provoking factors for development or exacerbation this pathology are infections and stress situations. Diet habits, chronic bacterial infections of respiratory tract are significant too. The obtained results can be used in development of a certain diet and preventive measures.

Kissing genetic MS risk loci to life.

Multiple sclerosis (MS) is an inflammatory autoimmune demyelinating disease of the central nervous system (CNS) [1]. Its debilitating effects on sensory, motor, autonomic, and neurocognitive functions affect primarily young adults, especially women (two to three times more frequent than in men), and is most frequent in northern countries, affecting more than 150 individuals of every 100,000 inhabitants e.g. in Canada and the Scandinavian countries. The development of this often initially relapsing/remitting and later progressive disease is associated with genetic and environmental risk factors [1, 3]. The major histocompatibility complex (MHC) class II gene locus is by far the most prominent genetic risk factor, and altered immune responses to the Epstein Barr virus (EBV), the causative infectious agent of most cases of infectious mononucleosis or “kissing disease”, have in recent years emerged as the most prominent environment induced risk factors for MS [1]. Interestingly, particularly infectious mononucleosis as symptomatic primary EBV infection, caused by a lymphocytosis of mainly lytic EBV antigen specific CD8+ T cells, and elevated antibody responses against EBV have been found to synergize with the MS associated MHC class II molecule HLA-DRB1*1501 to increase MS risk seven- to fifteen-fold, respectively [1]. Moreover, EBV infection seems to precede MS onset by several years in nearly all patients. Thus, EBV infection currently appears as a prerequisite for MS development that increases the risk for this autoimmune disease in genetically susceptible individuals.

Investigation of blood leptin and adropin levels in patients with multiple sclerosis: A CONSORT-clinical study.

Background:The effects of adipokines have been investigated in multiple sclerosis (MS) in the literature. Results are uncertain, and subgroups like adropin have not been previously studied. We primarily aimed to determine leptin and adropin levels in MS and their potential use as a biomarker.Methods:This study was an experimental research. While 44 MS patients diagnosed according to McDonald criteria were included in the patient group, 40 people without MS diagnosis and risk factors took part in the control group. Demographic data, height, weight, body mass index, blood glucose, thyroid-stimulating hormone, alanine transaminase, aspartate transaminase, creatinine, low-density lipoprotein, leptin, adropin levels, presence of hypertension, diabetes mellitus, coronary artery disease were recorded. Expanded disability status scale and disease duration were also evaluated in the patient group. Our data were presented as mean ± standard deviations.Results:The mean blood leptin value of the patient group (6.12 ± 5.34 ng/mL) was significantly lower than the value of the control group (13.02 ± 8.25 ng/mL) (P < .001). The patient group had a mean adropin level of 504.12 ± 311.17 ng/mL, which was significantly lower than that of the control group (747.0 ± 309.42 ng/mL) (P < .001). Statistically insignificant differences were found between their body mass index, glucose, alanine transaminase, aspartate transaminase, thyroid-stimulating hormone, low-density lipoprotein levels (P > .001).Conclusion:This is the first study that has evaluated adropin levels in patients with MS. The relationship between MS and leptin levels is still unclear. Therefore, our study might be helpful to elucidate MS pathogenesis and provide supportive criteria for diagnosis.

Analytical epidemiology of multiple sclerosis in the Republic of Kabardino-Balkaria

Multiple sclerosis (MS) is a common autoimmune disease, which etiology includes a complex of genetic and environmental factors. Data suggests that their interaction can influence the age of the clinical manifestations and the course of the disease. Therefore, the study of risk factors of MS in regions with different ethnic compositions of the population and climatic and geographical characteristics is of considerable interest.Objective: to study MS risk factors prevalence in the Republic of Kabardino-Balkaria (RKB).Patients and methods. This case-control study of the representation of risk factors included a cohort of 112 MS patients living in two regions of the RKB (Nalchik and the Prokhladnensky district). The MS diagnosis was established with the McDonald criteria (2017). MS risk factors were assessed with a unified questionnaire. 112 respondents (matched by the main demographic characteristics and place of residence) were included in the control group.Results and discussion. MS patients from the Prokhladnensky district were significantly more likely to contact harmful chemical compounds, had higher consumption of smoked meat products; and suffered from viral infections more often (all differences were significant, p&lt;0.05). More patients with MS, regardless of their place of residence, had a history of scarlet fever than the controls (n=23; 19.5% and n=14; 13.4%, ratio indicator 0.43 (95% CI 0.32–1.01), p=0.041), and the maximum significance of this factor was found in patients who suffered from scarlet fever after the age of 15 years (n=7; 6.3% and n=1; 0.9%, ratio indicator 2.45 (95% CI 1.92–3.21), p=0.041). More patients with MS had a history of chickenpox (n=70; 62.5% and n=55; 41.1%; ratio indicator 0.78 (95% CI 0.65–0.94, p=0.032), the frequency of this factor was most significant in early (up to 7 years) disease onset. Regardless of the place of residence, patients with MS were more likely to suffer from tonsillitis and sinusitis in childhood (p=0.032).Conclusion. In the RKB, as in other regions of the Russian Federation, the risk of MS, along with a genetic predisposition, is primarily determined by environmental factors, such as contact with potentially harmful chemicals, history of somatic diseases, characteristics of the ecological situation, etc. Therefore, MS risk is higher in people exposed to these factors before the age of 7 years and does not depend on the place of residence.

Dietary risk factors of primary progressive multiple sclerosis: A population-based case-control study

ObjectivesThere are growing evidences on the role of nutritional factors in multiple sclerosis (MS) occurrence. But dietary data are limited in primary progressive type of MS (PPMS). We assessed the role of dietary factors during adolescence in PPMS risk. MethodsAn incident case-control study on 143 PPMS cases with definite diagnosis and 400 controls were conducted in Sina hospital, Tehran, Iran. Demographic data were collected. Data on nutritional habits during adolescence were obtained using questionnaire designed for multinational case–control studies of environmental risk factors for multiple sclerosis (EnvIMS-Q). Logistic regression models were run to evaluate the role of diet in PPMS risk. ResultsA significant association was founded between higher intake of dairy, seafood, red meat, poultry, vegetable, fruit and nut and lower risk of PPMS (P< 00.5). This association was dose dependent for all mentioned food groups except fruit. In the fully adjusted model, more intake of dairy (OR: 0.27; 95%CI: 0.14-0.53), seafood (OR: 0.21; 95%CI: 0.10-0.44), red meat (OR:0.44; 95%CI: 0.22-0.90), vegetable (OR: 0.19; 95%CI: 0.09-0.39), fruit (OR: 0.47; 95%CI: 0.22-0.99) and nut (OR: 0.29; 95%CI: 0.15-0.56) in the third tertiles resulted in significant reduction in PPMS risk. In case of poultry consumption, the association was meaningful just in the third tertile of crude model (OR: 0.54; 95%CI: 0.30-0.95). Nutrient supplementation with calcium, iron, folic acid, vitamin B12 and C were also related with more than 84% lower risk of PPMS. ConclusionOur data proposed that adequate intake of food groups and nutrient supplementation during adolescence may be effective in reducing adult-onset PPMS risk.

A validated generally applicable approach using the systematic assessment of disease modules by GWAS reveals a multi-omic module strongly associated with risk factors in multiple sclerosis

BackgroundThere exist few, if any, practical guidelines for predictive and falsifiable multi-omic data integration that systematically integrate existing knowledge. Disease modules are popular concepts for interpreting genome-wide studies in medicine but have so far not been systematically evaluated and may lead to corroborating multi-omic modules.ResultWe assessed eight module identification methods in 57 previously published expression and methylation studies of 19 diseases using GWAS enrichment analysis. Next, we applied the same strategy for multi-omic integration of 20 datasets of multiple sclerosis (MS), and further validated the resulting module using both GWAS and risk-factor-associated genes from several independent cohorts. Our benchmark of modules showed that in immune-associated diseases modules inferred from clique-based methods were the most enriched for GWAS genes. The multi-omic case study using MS data revealed the robust identification of a module of 220 genes. Strikingly, most genes of the module were differentially methylated upon the action of one or several environmental risk factors in MS (n = 217, P = 10− 47) and were also independently validated for association with five different risk factors of MS, which further stressed the high genetic and epigenetic relevance of the module for MS.ConclusionsWe believe our analysis provides a workflow for selecting modules and our benchmark study may help further improvement of disease module methods. Moreover, we also stress that our methodology is generally applicable for combining and assessing the performance of multi-omic approaches for complex diseases.

T cell composition and polygenic multiple sclerosis risk: A population-based study in children.

Background and purposePatients with multiple sclerosis (MS) have altered T cell function and composition. Common genetic risk variants for MS affect proteins that function in the immune system. It is currently unclear to what extent T cell composition is affected by genetic risk factors for MS, and how this may precede a possible disease onset. Here, we aim to assess whether an MS polygenic risk score (PRS) is associated with an altered T cell composition in a large cohort of children from the general population.MethodsWe included genotyped participants from the population‐based Generation R study in whom immunophenotyping of blood T cells was performed at the age of 6 years. Analyses of variance were used to determine the impact of MS‐PRSs on total T cell numbers (n = 1261), CD4+ and CD8+ lineages, and subsets therein (n= 675). In addition, T‐cell‐specific PRSs were constructed based on functional pathway data.ResultsThe MS‐PRS negatively correlated with CD8+ T cell frequencies (p = 2.92 × 10−3), which resulted in a positive association with CD4+/CD8+ T cell ratios (p = 8.27 × 10−9). These associations were mainly driven by two of 195 genome‐wide significant MS risk variants: the main genetic risk variant for MS, HLA‐DRB1*15:01 and an HLA‐B risk variant. We observed no significant associations for the T‐cell‐specific PRSs.ConclusionsOur results suggest that MS‐associated genetic variants affect T cell composition during childhood in the general population.

Environmental risk factors of multiple sclerosis in the Middle East and North Africa region: A systematic review

Background: The environmental factors play a major role as risk factors of multiple sclerosis (MS). This study aimed at gathering environmental risk factors of MS in the Middle East and North Africa (MENA). Methods: We used MEDLINE and EMBASE databases by a systematic review method. Out of a total of 123 studies, 16 studies met the eligibility criteria. Results: Totally, 47 risk factors were assessed as follows: six studies found sunlight exposure as a protective factor with the odds ratio (OR) ranging from 0.06 to 0.57. Six studies evaluated smoking as a risk factor with the OR ranging from 1.69 in all patients to 6.48 in female patients. Four studies supported measles infection as a risk factor with the OR ranging from 1.60 to 3.77, and in 3 studies, stressful events had a significant association with the OR of 1.80, 1.90, and 32.57. Conclusion: Among 47 assessed risk factors, sunlight exposure, cigarette smoking, measles infection, Epstein-Barr virus (EBV) infection, and stressful events had a significant association with MS.

Cytomegalovirus seropositivity is associated with reduced risk of multiple sclerosis-a presymptomatic case-control study.

Epstein-Barr virus (EBV) and human herpesvirus 6A (HHV-6A) are associated with increased risk of multiple sclerosis (MS). Conversely, infection with cytomegalovirus (CMV) has been suggested to reduce the risk of MS but supporting data from presymptomatic studies are lacking. Here, it was sought to increase the understanding of CMV in MS aetiology. A nested case-control study was performed with presymptomatically collected blood samples identified through crosslinkage of MS registries and Swedish biobanks. Serological antibody response against CMV, EBV and HHV-6A was determined using a bead-based multiplex assay. Odds ratio (OR) with 95% confidence interval (CI) for CMV seropositivity as a risk factor for MS was calculated by conditional logistic regression and adjusted for EBV and HHV-6A seropositivity. Potential interactions on the additive scale were analysed by calculating the attributable proportion due to interaction (AP). Serum samples from 670 pairs of matched cases and controls were included. CMV seropositivity was associated with a reduced risk for MS (OR=0.70, 95% CI 0.56-0.88, p=0.003). Statistical interactions on the additive scale were observed between seronegativity for CMV and seropositivity against HHV-6A (AP 0.34, 95% CI 0.06-0.61) and EBV antigen EBNA-1 (amino acid 385-420) at age 20-39years (AP 0.37, 95% CI 0.09-0.65). Cytomegalovirus seropositivity is associated with a decreased risk for MS. The protective role for CMV infection in MS aetiology is further supported by the interactions between CMV seronegativity and EBV and HHV-6A seropositivity.

High antibody levels against human herpesvirus-6A interact with lifestyle factors in multiple sclerosis development

Background: Infection with human herpesvirus 6A (HHV-6A) has been suggested to increase multiple sclerosis (MS) risk. However, potential interactions between HHV-6A and environmental/lifestyle risk factors for MS have not previously been studied. Methods: We used two Swedish population-based case-control studies comprising 5993 cases and 5995 controls. Using logistic regression models, subjects with different HHV-6A antibody levels, environmental exposures, and lifestyle habits were compared regarding MS risk, by calculating odds ratios (ORs) with 95% confidence intervals (CIs). Potential interactions between high HHV-6A antibody levels and common environmental exposures and lifestyle factors were evaluated on the additive scale. Results: High HHV-6A antibody levels were associated with increased risk of developing MS (OR = 1.5, 95% CI = 1.4–1.6). Regarding MS risk, significant interactions were observed between high HHV-6A antibody levels and both smoking (attributable proportion (AP) = 0.2, 95% CI = 0.1–0.3), low ultraviolet radiation (UVR) exposure (AP = 0.3, 95% CI = 0.1–0.4), and low vitamin D levels (AP = 0.3, 95% CI = 0.0–0.6). Conclusion: High HHV-6A antibody levels are associated with increased MS risk and act synergistically with common environmental/lifestyle risk factors for MS. Further research is needed to investigate potential mechanisms underlying the interactions presented in this study.

Risk Factors Associated with Multiple Sclerosis: A Case-Control Study in Damascus, Syria.

Objectives To assess the probable risk factors associated with Multiple sclerosis among Syrian patients in the city of Damascus. Method In a case-control study conducted from May to September 2020, 140 MS patients and 140 healthy controls were selected from two main hospitals in Damascus. Data regarding risk factors associated with MS was collected via a structured questionnaire and complementary laboratory tests. The statistical analysis was carried out by the SPSS Statistical Software Version 26. Results Factors such as smoking, family history of MS, migraine, and vitamin D deficiency were associated with a higher risk of developing MS: Smoking (OR = 2.275 95% CI (1.348-3.841) P = 0.002). Family history of MS (OR = 3.970 95% CI (1.807-8.719) P ≤ 0.001). Migraine (OR = 3.011 95% CI (1.345-6.741) P = 0.005). Vitamin D deficiency (OR = 4.778 95% CI (2.863-7.972) P ≤ 0.001). However, factors such as diabetes, hypertension, a surgical history of appendectomy, tonsillectomy, and being the first-born in a family were statistically irrelevant: Diabetes (OR = 0.652 95% CI (0.226-1.882) P = 0.426). Hypertension (OR = 1.445 95% CI (0.724-2.885) P = 0.295) Appendectomy (OR = 1.269 95% CI (0.486-3.317) P = 0.626) Tonsillectomy (OR = 1.280 95% CI (0.576-2.843) P = 0.544). First-born Child (OR = 0.933 95% CI (0.558-1.562) P = 0.793). Conclusion Our study suggests that smoking, vitamin D deficiency, family history of MS, and migraine are probable risk factors for multiple sclerosis. Therefore, engaging in outdoor activities and maintaining a healthy diet—for females in particular—is highly recommended.

Gene-Environment Interactions in Multiple Sclerosis: A UK Biobank Study.

ObjectiveWe sought to determine whether genetic risk modifies the effect of environmental risk factors for multiple sclerosis (MS). To test this hypothesis, we tested for statistical interaction between polygenic risk scores (PRS) capturing genetic susceptibility to MS and environmental risk factors for MS in UK Biobank.MethodsPeople with MS were identified within UK Biobank using ICD-10–coded MS or self-report. Associations between environmental risk factors and MS risk were quantified with a case-control design using multivariable logistic regression. PRS were derived using the clumping-and-thresholding approach with external weights from the largest genome-wide association study of MS. Separate scores were created including major histocompatibility complex (MHC) (PRSMHC) and excluding (PRSnon-MHC) the MHC locus. The best-performing PRS were identified in 30% of the cohort and validated in the remaining 70%. Interaction between environmental and genetic risk factors was quantified using the attributable proportion due to interaction (AP) and multiplicative interaction.ResultsData were available for 2,250 people with MS and 486,000 controls. Childhood obesity, earlier age at menarche, and smoking were associated with MS. The optimal PRS were strongly associated with MS in the validation cohort (PRSMHC: Nagelkerke's pseudo-R2 0.033, p = 3.92 × 10−111; PRSnon-MHC: Nagelkerke's pseudo-R2 0.013, p = 3.73 × 10−43). There was strong evidence of interaction between polygenic risk for MS and childhood obesity (PRSMHC: AP = 0.17, 95% CI 0.06–0.25, p = 0.004; PRSnon-MHC: AP = 0.17, 95% CI 0.06–0.27, p = 0.006).ConclusionsThis study provides novel evidence for an interaction between childhood obesity and a high burden of autosomal genetic risk. These findings may have significant implications for our understanding of MS biology and inform targeted prevention strategies.

The relationship of HLA-G 14-bp insertion/deletion genetic polymorphism to the risk of multiple sclerosis and its clinical phenotypes

BackgroundHuman leukocyte antigen (HLA)-G molecule has been suggested to have a potential immunomodulatory role in multiple sclerosis (MS). Genetic variant sites of HLA-G molecule have been reported to be associated with autoimmune diseases. Identifying the genetic risk factors of MS may help in preventive strategies and anticipating disease progression. The aim of this work was to investigate the effect of HLA-G 14-base-pair insertion/deletion (14-bp INS/DEL) genetic polymorphism on MS risk and clinical characteristics and to observe the clinical characteristics of the MS patients’ group. The study included 48 MS patients and 50 cross-matched healthy controls, who were recruited from Sohag and Assiut university hospitals. Genetic testing (14-bp Ins/Del gene polymorphism) using polymerase chain reaction (PCR) was performed for patients and control groups. All patients had a detailed clinical assessment and have undergone measurement of disability using the Expanded Disability Status Scale (EDSS).ResultsNo statistically significant difference was found between MS patients and healthy controls (HC) in genotypic and allelic frequencies of HLA-G 14-bp INS/DEL polymorphism (P=0.305). No significant association was found between HLA-G 14-bp INS/DEL polymorphism genotypes and clinical characteristics or degree of disability of MS patients. The most frequent presenting symptoms of MS were motor symptoms. Fatigue was the most reported symptom along the course of MS disease.ConclusionAlthough it has been long known that HLA-G represents an important MS susceptibility locus, in this study, no significant relation could be detected between the 14-bp INS/DEL polymorphism genotype and MS susceptibility. MS risk susceptibility may be not linked to a single allele but may depend on the combination of different polymorphic genetic sites. In this study, the lack of genetic susceptibility may be attributed to ethnic factor.