Evidence of a founder effect for four cathepsin C gene mutations in Papillon-Lefèvre syndrome patients
- Y Zhanga,
- T Lundgrenb,
- S Renvertc,
- D N Tatakisb,
- E Firatlid,
- C Uygurd,
- P S Harte,
- M C Gorrya,
- J J Marksa,
- T C Harta,e
- aDepartment of Oral Biology, University of Pittsburgh School of Dental Medicine, 614 Salk Hall, 3501 Terrace Street, Pittsburgh, PA 15261, USA, bDepartment of Periodontics, Loma Linda University, Loma Linda, CA 92354, USA, cDepartment of Health Sciences, Kristianstad University, Sweden, dDepartment of Periodontology, University of Istanbul School of Dentistry, Istanbul, Turkey, eDepartment of Human Genetics, University of Pittsburgh, Graduate School of Public Health, Pittsburgh, PA 15261, USA
- Dr T C Hart, hart{at}cpc.pitt.edu
- Revised 27 November 2000
- Accepted 28 November 2000
Abstract
We describe a mutation and haplotype analysis of Papillon-Lefèvre syndrome probands that provides evidence of a founder effect for four separate cathepsin C mutations. A total of 25 different cathepsin C mutations have been reported in 32 families with Papillon-Lefèvre syndrome (PLS) and associated conditions. A characteristic of these findings is the diversity of different cathepsin C mutations that have been identified. To evaluate the generality of cathepsin C mutations, PLS probands representative of five reportedly unrelated Saudi Arabian families were evaluated by mutational and haplotype analyses. Sequence analysis identified two cathepsin C gene mutations: a novel exon 7 G300D mutation was found in the proband from one family, while probands from four families shared a common R272P mutation in exon 6. The R272P mutation has been previously reported in two other non-Saudi families. The presence of the R272P mutation in probands from these four Saudi families makes this the most frequently reported cathepsin C mutation. To distinguish between the presence of a possible founder effect or a mutational hot spot for the R272P mutation, we performed haplotype analysis using six novel DNA polymorphisms that span a 165 kb interval containing the cathepsin C gene. Results of haplotype analysis for genetic polymorphisms within and flanking the cathepsin C gene are consistent with inheritance of the R272P mutation “identical by descent” from a common ancestor in these four Saudi families. Haplotype analysis of multiple PLS probands homozygous for other cathepsin C mutations (W249X, Q286X, and T153I) also supports inheritance of each of these mutations from common ancestors. These data suggest that four of the more frequently reported cathepsin C mutations have been inherited from common ancestors and provide the first direct evidence for a founder effect for cathepsin C gene mutations in PLS. Identification of these six short tandem repeat polymorphisms that span the cathepsin C gene will permit haplotype analyses to determine other founder haplotypes of cathepsin C mutations in additional PLS families.
