A large proportion of Ashkenazi Jews and North African Arabs with Parkinson’s disease carry the same single gene mutation, according to two studies. The mutation -- apparently derived from a single “founder” individual several centuries ago -- was found in 18.3% of a cohort of 120 Ashkenazi Jews treated for Parkinson’s at the Albert Einstein College of Medicine and Beth Israel Medical Center here. The same mutation was found in 39% of a cohort of 76 Arabs with the disease, French researcher said. Both studies were published as letters in the Jan. 26 issue of the New England Journal of Medicine. The single-base-pair alteration, dubbed G2019S, is found on exon 41 of the leucine-rich repeat kinase 2 (LRRK2), according to Laurie Ozelius, Ph.D., of the Albert Einstein College of Medicine and lead author of the paper describing the Jewish cohort. Overall, Dr. Ozelius said, 22 of the 120 Parkinson’s patients carried the mutation, but only four of 317 controls with the same ethnic background carried the mutation. Carrying the mutation gave an odds ratio for disease of 17.6, with a 95% confidence interval ranging from 5.9 to 52.2. Also, the mutation was found in 11 of 37 (29.7%) of patients with a familial pattern of disease, and 11 of 83 (13.3%) patients with apparently sporadic disease. One implication of the finding, Dr. Ozelius said in an interview, is that many patients thought of as having sporadic disease probably have familial -- but unknown or unrecognized -- connections.
