Multiple Sclerosis (MS) is a chronic neurodegenerative disorder in the central nervous system that, effecting young adults, leading to non-traumatic disabilities. This disease starts as an auto-immune disease in which CD4 T cells cross the blood brain barrier and attack myelin sheaths of olygodendrocytes resulting in demyelination (Gandhi et al., 2010; Lund et al., 2013). Initially this is a transient process and re-myelination occurs, so initial stage of the disease is characterized by neurological dysfunctions that eventually recover. However this re-myelination is not permanent (Compston and Coles, 2008; Wakerley et al., 2012). The continuous immune attacks cause serious pathological changes of myelin sheaths hence disease progression and development of serious disabilities . (Makris et al., 2013; Wakerley et al., 2012; Hafler, 2004; Nylander and Hafler, 2012; Eshaghi et al., 2013). Peak age of the initial diagnosis of MS is 30 and the disease progress overtime causing a in decline in health and even mortality (Makris et al., 2013). Though it is subjective the average decrease in life expectancy of a patient with MS is 5 to 10 years after the disease is being diagnosed (Keegan and Noseworthy, 2002). Disabilities caused by the disease vary between patients and depend on the abnormalities of the neuronal track that is affected (Leray et al., 2010). Some disabilities include numbness, muscle atrophy and MS is often characterized by secondary depression as a result of the deteriorating physical health (Makris et al., 2013). Even though the disease was clinically diagnosed in the early 19th century, up to this date its cause is yet to be known (Nylander and Hafler, 2012). However, it is clear that genetic susceptibility and environmental factors play key roles in inducing the disease (Compston and Coles, 2008). Studies about MS show that discussing about the implication of these two factors separately is unproductive but the interplay between these factors together with cultural conditions cause the disease (Wakerley et al., 2012; Makris et al., 2013). Finding a geographical pattern in MS worldwide is a difficult task even today as it is unevenly distributed across the globe. MS has a prevalence rate of 83 per 100 000 individuals in the world with higher rate in northern countries. Europe has the highest prevalence of 193 per 100 000 individuals (Pugliatti et al., 2006). Australia and North America comes after Europe, which is a country at high risk for MS. However, Asian countries lie in the low risk category. Nevertheless, like every degenerative disease, in every population females are more prone to the disease than males (ratio 1:2). This ratio is found to gradually increase but it is not clear whether this is an increase due to females being more susceptible to the disease or more accurate diagnosis due to development of technology and awareness (Pugliatti et al., 2006; Koch-Henriksen and S√∏rensen, 2010). In1970s scientists were first able to recognize MS risk genes in MHC region of chromosome 6 (Nylander and Hafler, 2012). Despite of the lacking reproducibility in the search for MS risk genes for years, about four years ago, scientists were able to discover the exact location of the strongest MS related genes on chromosome 6, HLA (Human leukocyte antigen)region. Three culprit genes were identified on HLA region of the HLA-DR2 haplotype on chromosome 6p21; HLADRB1*1501 (encoding HLA-DR2b), HLADRB5*0101 (encoding HLADR2a) and HLADQB1*0602 (encoding HLA-DQ6), even though significant amount of details yet to be revealed. Research findings also reveal that among the three genes, the main susceptible gene to MS is HLADRBi*1501 (Sadovnick, 2012). The role of genetics in MS is unequivocal however, segregation analysis shows no clear mode of inheritance making MS a complex disease. There is a non-linear relationship between familial recurrence and the degree of relatedness, making the first, second and...
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