Clinical, genetic, and biochemical findings in two siblings with Papillon-Lefevre Syndrome

Background: Papillon-Lefevre Syndrome (PLS) is an autosomal recessive disease characterized by palmoplantar hyperkeratosis and severe periodontitis affecting both primary and secondary dentitions. Cathepsin C (CTSC) gene mutations are etiologic for PLS. The resultant loss of CTSC function is responsible for the severe periodontal destruction seen clinically. Methods: A 4-year-old female (case 1) and her 10-year-old sister (case 2) presented with palmoplantar skin lesions, tooth mobility, and advanced periodontitis. Based on clinical findings, the cases were diagnosed with PLS. Mutational screening of the CTSC gene was conducted for the cases, and their clinically unaffected parents and brother. Biochemical analysis was performed for CTSC, cathepsin G (CTSG), and elastase activity in neutrophils for all members of the nuclear family. The initial treatment included oral hygiene instruction, scaling and root planing, and systemic amoxicillin-metronidazole therapy. Results: CTSC mutational screening identified a c.415G > A transition mutation. In the homozygous state, this mutation was associated with an almost complete loss of activity of CTSC, CTSG, and elastase. Although monthly visits, including scaling, polishing, and 0.2% chlorhexidine digluconate irrigation were performed to stabilize the periodontal condition, case I lost all her primary teeth. In case 2, some of the permanent teeth could be maintained. Conclusions: This report describes two siblings with a cathepsin C gene mutation that is associated with the inactivity of cathepsin C and several neutrophil serine proteases. The failure of patients to respond to periodontal treatment is discussed in the context of these biological findings.