Heterogeneity in multiple sclerosis: comparison of clinical manifestations in relatives.

Once diagnosed to have MS, relatives of persons who have been previously diagnosed frequently ask whether their disease course will follow that of their relative(s) with MS. The present study compared the following clinical manifestations of MS among 43 index cases and 47 of their relatives, all of whom were diagnosed to have MS and regularly attended the MS Clinic in Vancouver, British Columbia: (i) age of onset of MS, (ii) clinical course, (iii) lesion site(s) and (iv) initial symptom(s) of MS. The results from the present study are preliminary because of the small size of the study group. However, these data suggest that apart from possibly age of onset between sibling pairs, the clinical manifestations of MS are not correlated among relatives who are assessed according to the same methodology. This is significant for counselling newly diagnosed relatives of longstanding MS patients.