ABSTRACT
In this study, peptidase A [pep A] was successfully typed in hair root sheaths obtained from 320 unrelated Egyptian population sample of both sexes using electrophoresis technique. In each case, hair sample was typed first for pep A and confirmed by typing blood from the same donor. Peptidase A activity was found in 300 of the samples and the other 20 samples showed no activity as they had no outer root sheath indicating that enzyme activity was present only in sheath material. Three phenotypes of peptidase A were controlled by two alleles. The most frequent phenotype was pep A1-1, while the least frequent one was pep A2-2. The most frequent allele was pep A*1 with a frequency of 0.806. The phenotypic distribution of peptidase A in the Egyptian population sample was in a close agreement with that predicted by Hardy-Weinberg equation