The primary aim of this study was to confirm the diagnosis for those patients suspected to have Papillon Lefevre syndrome based upon clinical diagnosis by carrying out mutation analysis of Cathepsin C gene of the patients and their unaffected family members. We have examined four families with Papillon Lefevre syndromeWe have examined four families with Papillon Lefevre syndrome, and evaluated the gene encoding cathepsin C for mutations. The mutation detection strategy consisted of polymerase chain reaction amplification of all seven exons and flanking intronic sequences, followed by direct nucleotide sequencing. Sequence analysis of the 7 cases revealed the presence of mutations in all the seven patients. Our second aim was to review the different periodontal regimens and evaluate the effect of a comprehensive preventive program, based on mechanical plaque control and systemic antibacterial measures, on periodontal health and preservation of teeth in PLS patients. According to the evaluation of the periodontal recordings, deterioration of the periodontal status was inevitable in case 1 while in case 2 the periodontal status was maintained more or less stable over the two-year period of the study.