The aim of this study was to evaluate the screening policies of cystic fibrosis 
(CF) in the Jewish population. The prevalence of mutations that account for CF 
in Israel have been defined in the past by determining the frequency of CF 
mutations in affected individuals. This study is a population-based study and 
is, therefore, different from previous patient-based studies. We found that the 
CF mutations D1152H, W1089X, and 405 + IG-->A were present in some ethnic groups 
in which no CF patients carrying these mutations were reported. These facts 
necessitate a reevaluation of the screening policy regarding the ethnic groups 
in Israel. We studied 9,430 healthy Jewish Israeli individuals of 36 countries 
of origin. The prevalence of CF mutations was 1:19, 1:19, 1:28, and 1:42 for the 
Ashkenazi, Sephardi, North African, and Eastern Jews, respectively. CF mutations 
were identified in 374 (4.0%) individuals. These included 173 (46.3%) carriers 
of the W1282X mutation; 110 (29.4%) found to carry delF508; 23 (6.1%) who 
carried G542X; 22 (5.9%) who carried 3849 + 10Kb (C-->T; 20 (5.3%) who carried 
D1152H; 10 (2.7%) who carried N1303K; 11 (2.9%) who carried 405 + IG-->A; 4 
(1.1%) who carried W1089X; and one (0.3%) who carried S549R. No carriers were 
detected for the 1717-1G-->A, G85E, and T360K mutations, which were tested for 
in 7,383, 1,558, and 41 individuals, respectively.