The frequency of expression of a phenotypic characteristic; i.e., high penetrance refers to a high degree of manisfestation of a phenotypic trait associated with a particular gene; the converse would be true of a low penetrance gene.
The frequency with which individuals with the necessary genotype express symptoms of a genetic condition.
The probability of detecting the presence or clinical expression of a gene or combination of genes when they are present. If the penetrance of a particular disorder is less than 100%, not all individuals who carry a mutation in the gene or genes responsible for the disorder will develop symptoms. Such a disorder is said to have reduced or incomplete penetrance.
An individual who carries a dominant gene may show a variable degree of the symptoms of the disorder.
The regularity or frequency with which a specific gene yields its effect or "is expressed." For example, if a specific gene produces a disease in all individuals who carry the gene, it is termed 100% penetrant. If a gene produces the disease less than 100% of the time, it is not fully penetrant.
In genetics, the frequency of expression of a genotype.
The proportion of affected individuals among the carriers of a particular genotype. If all individuals who have a disease genotype show the disease phenotype, then the disease is said to be "completely penetrant".
The likelihood, or probability, that a particular genotype will be expressed in the phenotype. A penetrance of 100% means that the associated phenotype always occurs when the corresponding genotype is present. Similarly, if only 30% of those carrying a particular allele (such as a disease-causing mutation) exhibit a phenotype (the disease), the penetrance is 30%.
The extreme case of reduced expressivity is incomplete penetrance. An inherited disease has incomplete penetrance in cases where the individual is known to have the affected genotype, but never shows the clinical disease. Even so, the clinical disease shows up again in its offspring. Clearly, the affected genes were present in the parent but the disease didn’t “penetrate” to a recognizable state. Again, this case must not be confused with a case of false positive. Incomplete penetrance has been documented in some PRA-affected Toller pedigrees.
The frequency with which a genotype manifests itself in a specific phenotype; the proportion of individuals who manifest that genotype at the phenotypic level. For example, if 100 females have two D mutations and 70 have symptoms of the disorder, the penetrance is 70%.
Of a genotype, the proportion of individuals with that genotype who show the expected phenotype.
The frequency with which a dominant allele will express itself when paired with a different allele. Example: Bb dogs are always black, so the B allele is fully (or 100%) penetrant. If a quarter of such dogs were red, then the allele would have 75% penetrance.
The extent to which a mutation causing a particular disorder causes clinical symptoms of that disorder. Usually refers to autosomal dominant conditions.
The proportion of individuals with a specific genotype that express the associated phenotype. close window
The proportion of individuals with a mutation causing a particular disorder who exhibit clinical symptoms of that disorder; a condition (most commonly inherited in an autosomal dominant manner) is said to have complete penetrance if clinical symptoms are present in all individuals who have the disease-causing mutation, and to have reduced or incomplete penetrance if clinical symptoms are not always present in individuals who have the disease-causing mutation.
The proportion of individuals with a mutation causing a particular disorder who exhibit clinical symptoms of that disorder; most often refers to autosomal dominant conditions. Related Terms: autosomal dominant ; intrafamilial variability ; variable expressivity
The percentage of individuals carrying a given mutation who will manifest the disease.
The proportion of individuals who carry a disease-causing gene that actually exhibit the disease symptoms.
the observable expression of a mutant gene
Refers to the proportion of individuals heterozygous for a given dominant allele that express the phenotype of that dominant allele.
Probability that a disease genotype will result in an abnormal phenotype.
The likelihood that a person carrying a mutation will develop the characteristics caused by that mutation
The characteristic phenotypic effect of a genotype. If the phenotype is always expressed in the presence of the genotype, the genotype is completely penetrant. If it is not always expressed, it is incompletely penetrant.
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. The percent penetrance also may change with the age range of the population.
a characteristic of a genotype; it refers to the chance that a clinical condition will occur when a particular genotype is present.
the proportion of individuals of a specified genotype that show the expected phenotype under a defined set of environmental conditions
The likelihood that a person carrying a particular mutant gene will have an altered phenotype.
Chance that an allele change in coding sequence results in a particular disease
The prevalence of individuals with a given genotype that manifest clinically the phenotype associated with that trait.
the probability of expressing a phenotype given a genotype. Penetrance is described as either"complete"or"incomplete." For example, individuals who carry the gene for tuberous sclerosis have an 80% chance of expressing the disorder. Penetrance may also be dependent on a susceptible individual's current age. For example, 20% of all gene carriers for myotonic dystrophy express the gene to some degree by age 15 while 80% of all gene carriers express it by age 60. Incomplete penetrance is usually a matter of chance or modifiers in the genetic background. [Source: NHBLI/NCBI Glossary
The probability that a particular gene mutation will produce the disease.
The likelihood that a given genotype will result in expression of the corresponding phenotype.
The likelihood that a given allele will actually result in disease. If a mutated allele is fully penetrant this means all individuals who have this mutation will develop the disease. See also: Allele See also: Mutation.
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". Incomplete penetrance is usually a matter of chance or modifiers in the genetic background.
The degree to which a genetic disorder is expressed phenotypically.
Penetrance refers to the probability that an individual with a disease-causing mutation will experience any signs or symptoms of that disease. Penetrance is an all-or-none concept. See Reduced penetrance.
The proportion of individuals with a specific genotype who manifest that genotype at the phenotype level.
The extent to which the inheritance of a mutated gene results in illness or other physiologic manifestation. The proportion of individuals with the genotype (such as hMSH2 germ-line carriers of HNPCC) who manifest the phenotype. A gene is considered to be completely penetrant if it is always associated with illness, and incompletely penetrant if it is not.
The likelihood that a defect or change in a gene that is common to a species will lead to a trait or disease.
the proportion of people with a given genetic mutation that show symptoms of disease. A gene mutation is considered to be completely penetrant if it is always associated with illness, and incompletely penetrant if only some of the people with the mutation will develop the illness
the frequency of expression of an allele when it is present in the genotype of the organism (if 9/10 of individuals carrying an allele express the trait, the trait is said to be 90% penetrant); the percentage of a population that carries a gene and actually expresses it in the phenotype
The frequency of manifestation of a hereditary condition in individuals.
Penetrance is a term used in genetics that describes the extent to which the properties controlled by a gene, its phenotype, will be expressed.