Absence of Multiple Sclerosis and Demyelinating Diseases among Lacandonians, a Pure Amerindian Ethnic Group in Mexico. Flores J, González S, Morales X, Yescas P, Ochoa A, Corona T Mult Scler Int. 2012; 2012:292631. Epub 2012 Aug 29. PMID: 22973516. Abstract CommentRecommendBookmarkWatch