Heat inactivation of plasma hydrolases as a means of discriminating between the genotypes in cystic fibrosis: the experience in Israel.

The ability to discriminate between cystic fibrosis (CF) patients, carriers and control subjects, by determining the degree of hear inactivation of certain plasma enzymes has recently been reported. Material from Israel on 39 patients, 68 carriers and 65 control subjects, was tested under the originally described conditions with concordant results and distinct separation of the three genotypes. No carriers were detected in the 65 control subjects, perhaps because of the dilutional effect of those ethnic groups in Israel among whom the frequency of the CF gene is known to be rare. Biochemically, no evidence of heterogeneity of CF was found among the various ethnic groups.