Friday, April 6, 2012

Genetic and Environmental Risk Factors for Alzheimer's Disease in Arabs Residing in Israel

There is relatively little known about the distribution of Alzheimer's disease (AD) around the world. Knowledge of high- or low-prevalence foci of disease may aid our understanding of disease mechanisms. Alzheimer's disease occurs less frequently in Asia than in Europe and North America, probably because of lower allele frequency of the apolipoprotein E (apo E) e4 allele. The disease appears to be also less common in India and Africa.

There are few studies of the disease in Arabs, and few in populations with a high level of consanguinity. We have found a remarkably high prevalence of the disease in Arabs residing in Israel. In a study in Tunisia, unspecified dementia was found to be 3 times less prevalent than in the United States. Treves, Chandra, and Korczyn (1993) found a lower prevalence of presenile AD in Sephardi, as compared with Ashkenazi Jews, but more late-onset disease in Sephardi than Ashkenazi, perhaps because of lower levels of education in Sephardi. The state of Israel is comprised of about 5 million Jews and 1 million non-Jews, mostly Moslem Arabs. This Arab population of Israel is valuable for medical research because of a high level of inbreeding, large family size, high level of smoking exposure, high level of medical care available through the Israeli Health System, excellent demographic databases available from the government, absence of alcohol use because of the religious proscription, and high participation rate (>98%).