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Penetrance

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penetrance
the percentage of individuals of a specific genotype that express an expected phenotype
Source: Jenkins, John B. 1990. Human Genetics, 2nd Edition. New York: Harper & Row ...


Penetrance: The percentage of individuals in a population that actually exhibit the (mutant) phenotype even though they carry the mutation
Expression: This refers to the consistency of the mutation. Basically even though the mutation penetrates it may have variable degrees of expression.

penetrance
In genetics, the proportion of individuals with a particular genotype that show the phenotype ascribed to that genotype.
peptide bond ...

penetrance /PEN-ə-trəns/ The probability of a genotype being expressed. When penetrance is complete, the genotype is expressed in all individuals who have that genotype. When it is incomplete the genotype is expressed in only part of the population.

Penetrance Pertaining to the failure of some animals with a mutant genotype to express the associated mutant phenotype. In any case where less than 100% of genotypically mutant animals are phenotypically mutant, the phenotype is said to be "incompletely penetrant".

Penetrance. The degree to which a mutant genotype is expressed as a phenotype. Incomplete penetrance is usually due to modifiers in the genetic background.
Phenotype. Observable characteristics of a cell or organism.

Penetrance
The probability of a gene or genetic trait being expressed. "Complete" penetrance means the gene or genes for a trait are expressed in all the population who have the genes. "Incomplete" penetrance means the genetic trait is expressed in only part of the population.

Nonpenetrance
The influence of other, unidentified factors can be seen when some individuals in a study do not display the phenotype normally associated with their defined genotype, a situation termed nonpenetrance.

Penetrance
Term coined by Voigt (1926) for the percentage with which a dominant or homozygous recessive gene expresses itself in the phenotype. Qualitative concept of gene expression. It depends both on genotype and environment.
If all individuals of the genotype show the trait, penetrance is 100%.

Gene penetrance is the percentage of phenotypical manifestation of a gene in a given population of carrier individuals (same genotype).

Table 1. Penetrance of phenotypes in Ptdsr -/- mice from E9.5 to E18.5, as detected by gross morphology
Expression of Ptdsr during embryogenesis and in adult tissues ...

Penetrance An "ll or none" reference to clinical expression of a mutant gene.
Phage A virus for which the natural host is a bacterial cell.
Physical map A map of the locations of identifiable landmarks on DNA (e.g., restriction enzyme cutting sites, genes), regardless of inheritance.

Expressivity: The range of phenotypes resulting from a given genotype (cystic fibrosis, for example, may have a variable degree of severity). This is different from pleiotropy which refers to a variety of different phenotypes resulting from the same genotype, or from penetrance.

The term is typically used to describe heterozygotes for mutations that cause recessive disease, but it is also used to describe heterozygotes for risk alleles of complex traits with variable penetrance, regardless of inheritance type.
Carrier rate — The frequency of carriers in a population.

In order to better understand the incomplete penetrance of M1-associated control, we used the Illumina HiSeq platform and 90 bp paired-end reads to sequence the genomes of all 12 Cohort A animals, as well as six additional animals described in [9]. On average, 1.

Is there variable expressivity and/or incomplete penetrance?
Is there a clear and accurate legend?
Are the symbols used correctly? Are unknown phenotypes indicated?
Are the generations and individuals labeled correctly and referred to correctly in the accompanying analysis?

In the case of hemochromatosis, penetrance is incomplete, even for the classic HFE mutation, and is affected by gender, diet, and behaviors such as alcohol consumption. Compound heterozygotes are often observed only through subclinical symptoms such as excess iron.

Marfan's Syndrome is associated with incomplete penetrance, therefore not all persons carrying the mutation develop the disease. Without the structural support provided by fibrillin, many connective tissues are weakened, which can have severe consequences on support and stability.

Successful identification of behavioral genes is most likely when the gene shows a high penetrance, that is, the genotype is expressed in the phenotype. Degree of expression is also important for success in determining behavioral genes.

Incomplete penetrance -- the gene for a condition is present, but not obviously expressed in all individuals in a family with the gene. In situ hybridization -- hybridization of a labeled probe to its complementary sequence within intact, banded chromosomes.

See also: See also: Gene, Mutation, Organ, Order, Express

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