This occurs because of the lack of activation of cathepsin C in Papillon-Lefèvre syndrome, which ultimately results in deficit immunomodulatory and antimicrobial functions of LL-37 in gingiva that will allow bacteria such as Aggregatibacter actinomycecomitans to infect gingiva and periodontium to develop periodontal diseases. This evidence concerns the gene CTSC and Papillon-Lefèvre syndrome.