The Papillon-Lefèvre and Haim Munk syndromes are characterized by the presence of both palmoplantar hyperkeratosis (PPK) and severe
early onset periodontitis. It is the early onset
periodontal disease component that distinguishes these from other more common forms of PPK. It has been proposed that the
periodontal disease component may be a casual association in individuals with PPK. Genetic syndromes with
palmoplantar keratosis and severe ealry onset
periodontitis may be due to specific
bacterial infections in individuals with PPK. Recently,
keratin gene mutations have been identified in several conditions typified by
palmoplantar keratosis. The present study sought to test the hypothesis that a
keratin gene defect similar to those previously identified in other PPK conditions is responsible for the Haim Munk and the Papillon. Lefèvre syndromes. We have performed genetic linkage studies to test for linkage between polymorphic
DNA loci within 2
cytokeratin gene families and the disease phenotype in
Haim Munk syndrome and Papillon-Lefèvre syndrome. Families with individuals segregating for the
Haim Munk syndrome and the Papillon-Lefèvre syndrome were examined to determine disease status, and genotyped for microsatellite
DNA markers closely linked to the acidic (type I) and the basic (type II)
cytokeratin genes on chromosomes 12 and 17. Genotype data were evaluated for microsatellite allele homozygosity in affected individuals. Results of these preliminary genetic studies suggest that the gene defect in
Haim Munk syndrome is not due to a gene defect in either the type I or the
type II keratin gene clusters. These findings suggest that
Haim Munk syndrome may be genetically distinct from other more common forms of PPK that have been linked to the
cytokeratin gene families, and suggest that mutations in genes other than
keratin genes are responsible. Additional family studies are needed to confirm these preliminary findings.