A gene is a molecular unit of heredity in a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains. Genes hold the information to build and maintain an organism's cells and pass genetic traits to offspring, although some organelles (e.g. mitochondria) are self-replicating and are not coded for by the organism's DNA. All organisms have many genes corresponding to various different biological traits, some of which are immediately visible, such as eye color or number of limbs, and some of which are not, such as blood type or increased risk for specific diseases, or the thousands of basic biochemical processes that comprise life.
The relative distance between two genes can be calculated by taking the offspring of an organism showing two linked genetic traits, and finding the percentage of the offspring where the two traits do not run together. The higher the percentage of descendants that do not show both traits, the farther apart on the chromosome the two genes are. Genes for which this percentage is lower than 50% are typically thought to be linked.
Genetic linkage can also be understood by looking at the relationships among phenotypes. Among individuals of an experimental population or species, some phenotypes or traits can occur randomly with respect to one another, or with some correlation with respect to one another.
What's the relationship between gene combination and oral health? The health of the surrounding tissue affects the success of a dental implant. Identifying and reducing risk factors is therefore a key step in the implant process. Now a combination of genes has been identified as a possible indicator of greater tissue destruction leading to negative outcomes for implants.
A study compared two groups of patients, all of whom had implants. The first group consisted of 25 patients with peri-implantitis, while the second group of 25 patients had healthy tissue. Seventeen patients from the first group and five from the second group were genotype positive.
Patients in the first group, those with peri-implantitis, took part in a treatment and maintenance program. The genotype-positive patients in this group experienced greater periodontal tissue destruction and, increased discharge from tissues. The genotype-negative patients responded better to treatment. Statistically significant differences were noted between the groups.
The combination of these two alleles in patients with inflamed periodontal tissues denotes a risk factor that can lead to further tissue destruction. Patients with the specific genotype can have exaggerated local inflammation. Gene polymorphism may affect the outcomes of treatment for peri-implantitis in genotype-positive people and affect the long-term success of implants.
