MULTIPLE-SCLEROSIS - GENETIC VERSUS ENVIRONMENTAL ETIOLOGY - EPIDEMIOLOGY IN ISRAEL UPDATED

The incidence and prevalence of multiple sclerosis (MS) were compared, controlling for age, in native-born Israelis of different origins and in immigrants to Israel. This comparison was carried out in two popul ations, countrywide and in Jerusalem. In the countrywide population, a scertainment was based mainly on hospitalizations; it included 252 pat ients who were native-born and 150 who had immigrated from Africa-Asia (AA immigrants). The 89 MS patients of Jerusalem also included patien ts diagnosed in outpatient clinics. In native-born Israelis whose fath er was born in Europe-America (I-EA), the incidence and prevalence of MS were found to be as high as or even higher than that found previous ly in immigrants from Europe-America. Among native-born Israelis whose father was born in Africa or Asia (I-AA), the yearly age-adjusted inc idence and prevalence rates were found to be 1.4- to 1.8-fold higher t han among AA immigrants, pointing to environmental factors. The incide nce and prevalence rates in the I-EA were 1.2- to 1.6-fold higher than in the I-AA, pointing to genetic factors. These results seem to point to both environmental and genetic factors in the aetiology of MS. Fur ther research is needed, however, to disentangle the genetic factors f rom possible environmental differences in the two ethnic groups.