A genome-wide association study meta-analysis in a European sample of stage III/IV grade C periodontitis patients ≤35 years of age identifies new risk loci.

Aim: Few genome-wide association studies (GWAS) have been conducted for severe forms of periodontitis (stage III/IV grade C), and the number of known risk genes is scarce. To identify further genetic risk variants to improve the understanding of the disease aetiology, a GWAS meta-analysis in cases with a diagnosis at ≤35 years of age was performed.

Materials And Methods: Genotypes from German, Dutch and Spanish GWAS studies of III/IV-C periodontitis diagnosed at age ≤35 years were imputed using TopMed.

Genetic Susceptibility to Periodontal Disease in Down Syndrome: A Case-Control Study.

Severe periodontitis is prevalent in Down syndrome (DS). This study aimed to identify genetic variations associated with periodontitis in individuals with DS. The study group was distributed into DS patients with periodontitis ( = 50) and DS patients with healthy periodontium ( = 36).

Genome-wide association study of stage III/IV grade C periodontitis (former aggressive periodontitis) in a Spanish population.

Aim: To identify loci associated with stages III/IV, grade C periodontitis (PIII/IV-C) through a genome-wide association study (GWAS).

Materials And Methods: 441 Caucasian Spanish PIII/IV-C cases from the SEPA Network of Research Clinics and 1141 controls from the Banco Nacional de ADN were genotyped with "Axiom Spain Biobank Array," which contains 757836 markers, including rare and low-frequency Spanish variants. The analysis of the individual association and subsequently the gene-level analysis with Sequence Kernel Association Test (SKAT) were carried out adjusting for age, sex and PC1 covariates.

Assessment of genotyping tools applied in genetic susceptibility studies of periodontal disease: A systematic review.

Objective: A systematic review to evaluate the various genotyping tools and study strategies employed to define genetic susceptibility to periodontitis.

Methods: The review was performed in accordance with Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines. The search for publications referring to the genetic bases of periodontal disease was performed on the MEDLINE-PubMed and Cochrane Library databases, on trials registers, and on the web pages of regulatory agencies.

The scale-of-choice effect and how estimates of assortative mating in the wild can be biased due to heterogeneous samples.

The mode in which sexual organisms choose mates is a key evolutionary process, as it can have a profound impact on fitness and speciation. One way to study mate choice in the wild is by measuring trait correlation between mates. Positive assortative mating is inferred when individuals of a mating pair display traits that are more similar than those expected under random mating while negative assortative mating is the opposite.