Genes may be as important as diet and dental hygiene in the development of gum disease, suggests research in the Journal of Medical Genetics.
Late last year an international team of researchers discovered that changes (mutation) in a gene for the enzyme, cathepsin C, are responsible for a condition known as Papillon-Lefèvre syndrome. Sufferers experience scaly, warty thickening of the skin, principallyon the hands and soles of their feet (palmar-plantar keratosis), as well as erosion of the soft tissues lining the mouth and connecting bones (periodontitis) and inflammation of the gums (gingivitis). Cathepsin C, which is found in skin and bone cells, activates several of the chemicals controlling local immune and inflammatory responses.
They have now identified that different mutations of this same gene are responsible for two other related, although separate, syndromes: Haim-Munk syndrome in which the mouth tissues are not so badly affected, but in which the skin symptoms are more severe and extensive; and prepubertal periodontitis, a rare but rapidly progressive gum disease, but with no skin symptoms that affects young children. Periodontitis is thought to develop in up to 2 per cent of children.
The researchers studied 14 members of an extended Jordanian family. Four children with evidence of gum disease and extensive bone loss had mutations in both copies of their cathepsin genes. All four of their parents and two other children carried one copy of the mutated gene and one copy of the normal cathepsin gene, a factor which seemed to protect them from developing severe gum disease. This suggests that normal functioning of the cathepsin C gene is needed for healthy gums, say the authors. Dietary, bacterial, and other genetic factors may compromise cathepsin C function and so predispose an individual to gum disease, they conclude.
Why identical gene mutations cause both Papillon-Lefèvre syndrome and prepubertal periodontitis is not known, say the researchers.
Up to one in five adults may develop periodontitis. Smoking and bacterial infections are thought to have a major role in both initiating and speeding up its development, but genes may actually be the what determines who develops severe gum disease, because of the way in which an individual reacts to these initiating factors, conclude the authors.
Haim-Munk syndrome and Papillon-Lefèvre syndrome are allelic mutations in cathepsin C 2000;37:88–94 Localisation of a gene for prepubertal periodontitis to chromosome 11q14 and identification of a cathepsin C gene mutation 2000;37:95–101
Journal
Journal of Medical Genetics