[Multiple sclerosis in the black population].

Numerous epidemiological studies showed that The occurrence of multiple sclerosis (MS) was the result of genetic factors varying by ethnic group as well as geographical and environmental factors. It is difficult to estimate exactly the prevalence of MS among black Africans. Nevertheless it's possible to state that the disease is rare but present among those populations. Among black Americans prevalence of MS seems related to the degree of mixture with white population. Among West Indians the occurrence of MS is closely related to an environmental factor acquired in Europe before 15 years of age. Those data confirm the existence during childhood and adolescence of a critical period during which an environmental factor is acquired in regions of high prevalence for MS.