Aggressive periodontitis is likely influenced by a few small effect genes

Abstract

Aim-To evaluate the inheritance mode of aggressive periodontitis in a collection of families with a similar geographic origin.Material and Methods-Segregation analysis was performed in pedigree data from 74 families by the use of the SEGREG program of SAGE v.5.4.2. Homogeneous no transmission, homogeneous Mendelian transmission, homogeneous general transmission, semigeneral transmission and heterogeneous general transmission models were tested assuming the prevalence of aggressive periodontitis as 1% and no deviations from Hardy-Weinberg equilibrium. The parameters of the model were estimated by the method of maximum likelihood, which provides the overall ln (likelihood), −2ln and the AIC (Akaike's score) for each model. The likelihood ratio test (LRT) was used to compare each model against a fully general model (p>0,05).Results-The most parsimonious mode of inheritance was the semigeneral transmission model which allows the heterozygote transmission probability to vary. Conclusion-This Conflict of interest and sources of funding statementThe authors declare that there are no conflicts in this study. This study was supported in part by a grant from the Brazilian government: CAPES. NIH Public Access NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author ManuscriptScientific rationale for the study-Understanding the mode of inheritance of aggressive periodontitis can better guide future molecular studies aiming to identify contributing genetic factors to the condition.Principal findings-Our results provide strong support for the hypothesis that genetic factors play a role in aggressive periodontitis, under a model of variable heterozygote transmission.Practical implications-Family-based designs provide the opportunity to study variation in the phenotype and provide evidence that justifies future family-based genetic analysis. From these approaches comes the possibility to localize disease loci through linkage analysis. The identification of the genetic variation leading to aggressive periodontitis can improve individual risk assessments of this condition in the future.

Birth Weight of Infants of Mothers With Aggressive Periodontitis

“…We included two NP control groups in this study. It is established that AgP is a familial condition that likely has a significant underlying genetic etiology 23,37,38 . Thus, we considered it imperative to include an NP group of mothers who were first‐degree relatives of the subjects with AgP.…”

Efficacy of subgingival air polishing in patients with aggressive periodontitis

“…The prevalence of this form of periodontitis significantly varies between countries and depends on one's ethnicity 2,3,4 . The factors that may lead to aggressive periodontitis are numerous: above all, poor dental hygiene which leads to a build-up of oral bacteria forming a dental film 5,6 . Another significant factor causing this form of periodontitis is a compromised immune system.…”

Periodontal disease: a genetic perspective

“…Formal genetic studies (segregation analysis and linkage analysis) indicate that there are multiple different genetic forms of aggressive periodontitis, but it is currently unclear how many genes may be involved in these non-syndromic forms of disease. 5,25,29,30 This aggregation within families strongly suggests a genetic predisposition. 29 It is important to mention that familial patterns may also indicate exposure to common environmental factors within these families.…”

“…The significance of these conditions is that they clearly demonstrate that a genetic mutation at a single locus can impart susceptibility to periodontitis. 25 However, in contrast to non-syndromic forms of periodontitis, these conditions have periodontal disease manifestations as part of a collection of syndromic manifestations. In most cases of non-syndromic aggressive periodontitis, individuals present with clinical manifestations of periodontitis, but do not appear to have any other clinical disease manifestations.…”

“…These studies can also demonstrate the role of specific genes. 5,25 Some monogenic syndromes are associated with severe periodontal disease (acatalasia, hypophosphatasia, Chédiak-Highashi syndrome, chronic neutropenia, leukocyte adhesion deficiency, cyclic neutropenia, Ehlers-Danlos syndrome and PapillonLefèvre syndrome). [26][27][28] These conditions share the same genetic principle: they are inherited as simple Mendelian traits and are usually caused by genetic alterations of a single gene locus.…”