Gene-environment interactions and risk of pediatric-onset multiple sclerosis associated with time spent outdoors.

Nasr Z, Virupakshaiah A, Schoeps VA, Cherbuin N, Casper TC, Waltz M, Hart J, Rodriguez M, Gorman MP, Benson LA, Chitnis T, Rensel M, Abrams A, Krupp L, Waldman AT, Lotze T, Aaen GS, Mar S, Schreiner T, Wheeler Y, Rose J, Shukla NM, Barcellos LF, Lucas R, Waubant E