Cathepsin C gene 5'-untranslated region mutation in papillon-lefèvre syndrome.

Background: Papillon-Lefèvre syndrome (PLS) is a rare autosomal recessive disorder characterized by palmoplantar keratoderma together with a severe form of generalized aggressive periodontitis and associated with mutations in cathepsin C gene (CTSC).

Objective: To investigate the clinical and mutational characteristics of 6 PLS patients from 4 unrelated Slovenian families.

Methods: CTSC mutational and functional analyses were performed.

Results: In all patients, a novel homozygous substitution, c.-55C>A, in the CTSC 5'-untranslated region (UTR) was detected on genomic DNA level and confirmed by mRNA analysis, resulting in the almost complete loss of CTSC mRNA expression and CTSC activity. In silico analysis revealed the potential of the mutation to disrupt putative transcription factor binding sites (TFBSs) for AP-2 and Sp families of transcription factors.

Conclusion: Identification of a novel CTSC 5'-UTR mutation together with a severe reduction of CTSC mRNA expression and virtually nonexistent CTSC activity was suggestive of a novel mechanism of TFBS dysfunction associated with PLS.