Segregation analysis of mandibular prognathism in Korean orthognathic surgery patients and their families

Abstract

Objective: To investigate the existence of genetic influences on the incidence of mandibular prognathism (MP) in Korean Class III patients. Materials and Methods: The probands consisted of 100 Class III patients with MP (51 men and 49 women; mean age, 22.1 6 5.2 years; SNA, 81.2u 6 3.2u; SNB, 84.1u 6 3.9u) who underwent orthognathic surgery. Using three-generation pedigree charts, questionnaires, and clinical examinations, general information and information regarding MP for a total of 3777 relatives of the probands (1911 men and 1866 women) was ascertained. Familial correlations of MP between possible pairs in the pedigree were estimated. Heritability (h 2 ) of MP under various models was estimated. Segregation analysis was conducted under the assumption of the nonpolygenic multivariate logistic model and finite polygenic mixed model. One-, two-, and three-susceptibilitytype models were evaluated. Results: Among 3777 relatives, 199 (97 men and 102 women) were affected with MP (5.3%). Correlation coefficients of MP incidence in full siblings and in parent-offspring were .2003 and .2036, respectively (all P , .001). The h 2 of MP was estimated as 21.5% after adjusting for sex and founder effects. Two-and three-susceptibility-type models showed that the general model fit better than the other models. MP incidence did not have a major gene transmission model and was influenced by numerous minor effect genes and their additive effects. Conclusion: These results suggest that the inherited susceptibility to MP in Korean Class III patients might be due to the summation of minor effects from a variety of different genes and/or influence of environmental factors, rather than Mendelian transmission of major genes.

Targeted sequencing in FGF/FGFR genes and association analysis of variants for mandibular prognathism

“…[4] However, no significant association was found between variants of FGF23 and MP in this case-control association study. These suggests us that the genetic mechanisms of MP are complex, [37] the main effects of the identified variants are considered to confer relatively small increments in risk, and explain only a small proportion of the heritability.…”

“…Both monogenic (dominant or recessive) and polygenic inheritance manners have been suggested by different studies. [2–4] With the evidence accumulated, it is now accepted by most researchers that MP is a polygenic disorder with both environmental and genetic risk factors attributed to its etiology. [1,5,6] Although genetic linkage analysis and association studies have identified many genes and loci associated with MP, [1,7–17] the genes underlying the risk of MP in the general population remain elusive, leaving some impetus to search for new candidate genes.…”

A multilevel analysis of craniofacial growth in subjects with untreated Class III malocclusion

“…Interindividual variability was statistically significant for eight (Co‐Gn, Co‐A, ANS‐Me, SNA, SNB, ArGoMe, PP‐MP, NSBa) out of ten variables considered. Variability can be due to a summation of minor effects from a variety of different genes and/or from the influence of epigenetic factors …”

Mandibular Prognathism and Genetic Transmission in Turkish Families

“…28 In another study, the heredity pattern was found to be autosomal dominant with 0.70 incomplete penetrance. 25 Ko and colleagues 29 examined 100 Korean subjects with MP and concluded that both genetic and environmental factors are responsible for susceptibility to MP in Korean patients with Class III rather than Mendelian inheritance.…”