<prompt> Which of the following is false regarding Multiple Sclerosis MS?More common in women and age of onset is between 20-40 years of ageRisk factors include vitamin D deficiency and cigarette smokingPathological hallmark is axonal degenerationHLA DRB1 in MHC class II is associated with 10 of disease risk  <response>: Multiple sclerosis is an auto immune disease of central neural system with a relapsing and remitting or progressive course. The pathologic hallmark of disease is demyelination. Myelin specific antibodies are present on degenerating myelin sheaths. Surviving oligodendrocytes paially remyelinate surviving axons, which are called as shadow plaques. Reference: Harrisons Principles of Internal Medicine, 21st edition, p2661 