title: Why study relationships between diseases? Clues to the etiology of multiple sclerosis (MS) derived from family illness history.
mesh_terms: D000328:Adult; D003920:Diabetes Mellitus / Q000235:genetics*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009103:Multiple Sclerosis / Q000235:genetics*; D012306:Risk