Genetic risk factors for early-onset periodontitis

EARLY-ONSET PERIODONTAL DISEASES (EOP) are a heterogeneous group of diseases, sharing several characteristics including early onset and severe periodontal destruction. Although periodontopathogenic bacteria are primary etiologic agents in the disease process, familial aggregation of affected individuals suggests genetic factors also are important. Formal genetic studies suggest a pattern of disease transmission consistent with mendelian inheritance of a gene of major effect. This means that one or more genes could account for the observed familial pattern of some cases of early-onset periodontitis. Clearly, both genetic and environmental risk factors are important in EOP. Epidemiological studies can identify risk factors for periodontitis on the population level. Although the association of a suspected risk factor can be studied with classic epidemiological techniques, these techniques are generally not applicable to the assessment of risk in individuals. Now with the advent of molecular epidemiology, it is possible to begin development of individual susceptibility profiles that may incorporate both host genetic and environmental components. Evidence for a central role of genetic risk factors in EOP makes these diseases a practical model for such studies. This review presents the primary support for genetic risk factors for EOP diseases and presents some of the potential genetic factors that may be useful in developing molecular epidemiological risk profiles for EOP.