genetic factors in periodontal disease Flashcards
etiology
1) periodontal pathogens
2) disease modifying factors
3) host susceptibility
autosome
non sex chromosome
allele
one of several forms of a gene
locus
location of the gene
genome
entire hereditary information of an organism
penetrance
1) proportions of individuals who have a allele who express the associated trait
genetic polymorphism is
1) a locus in which 2 or more alleles occur in at least 1% of the population
mutation
1) changes in the DNA sequence of the genome from errors that occur during DNA replication
genotype
genetic makeup
phenotype
physical makeup
simple genetic disease
mutations of single genes
- autosomal dominant
- autosomal recessive
- x-linked
simple genetic diseases
1) sickle cell anemia
2) neurofibromatosis
3) hemophilia
4) papillon lefevre
complex genetic disease
1) mild phenotype
2) slowly progressive
3) chronic in nature
4) late onset
5) common
periodontitis as a complex genetic disease
1) 10-20 disease modifying genes
2) vary among ethnic groups
3) influenced by environmental factors
evidence of genetic susceptibility
1) 81% moderate
2) 8% rapid
3) 11% none
other evidence for genetic susceptibility
1) small percentage of subjects account for major percentage of tooth loss in several longitudinal studies
2) high prevalence of pathogenic bacteria found in subjects with gingivitis
familial aggregation
1) siblings of young patients with aggressive periodontitis often also suffered from severe periodontal breakdown
2) mode of inheritance
- autosomal dominant
3) 70% penetrance
4) african americans and caucasians
michalowicz study
1) twill studies that show 50% of periodontitis can be attributed to genetics
genetic disorders associated with aggressive periodontitis
1) papillon lefevre syndrome and cathepsin C gene; AR
2) chediak higashi syndrome
3) ehler danlos
4) cyclic neutropenia
5) leukocyte adhesion deficiency
mutation
1) permanent change in DNA sequence
2) alters AA sequence
3) simple genetics diseases, less than 1% of population
4) dramatically affect expression of function of a gene product
5) deterministic of disease
genetic polymorphisms
1) different alleles of a given gene co-exist in the human population
2) complex genetic diseases, greater than 1%
3) by itself, no deterministic of disease
4) multiple functional genetic polymorphisms interact with each other and with environmental factors
genetic polymorphisms associated with periodontitis
1) most are SNPS
2) linked to immune response
3) most studies show variable and inconclusive correlations
possible candidate genes
1) IL-6, IL-10, IL-1
2) TNF alpha
3) fc-gamma
4) TLRs
5) VDRs
6) CD-14
genetics tests for periodontitis
1) tests are available for simple mutations
2 )LAD types 1 and 2, PLS, CHS, etc
