penetrance

pen·e·trance

P0162700 (pĕn′ĭ-trəns)n. The frequency, under given environmental conditions, with which a specific phenotype is expressed by those individuals with a specific genotype.

penetrance

(ˈpɛnɪtrəns) n (Genetics) genetics the percentage frequency with which a gene exhibits its effect[C20: from penetr(ant) + -ance, on the model of German penetranz]

pen•e•trance

(ˈpɛn ɪ trəns)

n. the frequency, expressed as a percentage, with which a particular gene produces its effect in a group of organisms. Compare expressivity (def. 2). [1635–45]

Penetrance

penetrance

[′pen·ə·trəns] (genetics) The proportion of individuals carrying a dominant gene in the heterozygous condition or a recessive gene in the homozygous condition in which the specific phenotypic effect is apparent. Also known as gene penetrance.

Penetrance

a quantitative index of phenotypic variability in the expression of a gene. Penetrance is usually measured as the percent ratio of the number of individuals in whom the gene is expressed to the total number of individuals in whose genotype the gene is present in the homozygous state (for recessive genes) or heterozygous state (for dominant genes). Complete penetrance occurs when a certain gene is expressed in 100 percent of individuals with the appropriate genotype. Penetrance can also be incomplete, in which case it is called variable.

Variable penetrance is characteristic of the expressivity of many genes in humans, animals, plants, and microorganisms. For example, certain hereditary diseases of man develop only in a portion of the persons whose genotype contains the anomalous gene; in the remainder, the hereditary predisposition to the disease remains unrealized. Variable penetrance is due to the complexity and multistage nature of the many events that occur between the first actions of a gene on the molecular level and the eventual emergence of a trait. The penetrance of a gene may vary within broad limits, depending on the nature of the surrounding genes within the genotype. Strains of individuals with a given degree of penetrance may be obtained by artificial selection. The average degree of penetrance also depends on environmental conditions.

REFERENCES

Lobashev, M. E. Genetika, 2nd ed. Leningrad, 1967.
Timofeev-Resovskii, N. V., and V. I. Ivanov. “Nekotorye voprosy fenogenetiki.” In the collection Aktual’nye voprosy sovremennoi genetiki. Moscow, 1966. Pages 114–30.

V. I. IVANOV

penetrance

[pen´ĕ-trans] the frequency with which a heritable trait is manifested by individuals carrying the principal gene or genes conditioning it.

pen·e·trance

(pen'ĕ-trans), The frequency, expressed as a fraction or percentage, of people who are phenotypically affected, among those of an appropriate genotype (i.e., homozygous or hemizygous for recessives, heterozygous or hemizygous for dominants); for an autosomal dominant disorder, if only a proportion of people carrying the mutant allele display the abnormal phenotype, the trait is said to show incomplete penetrance. If all with the mutant allele show the abnormal phenotype, the trait is said to have complete or full penetrance. See: penetration.

penetrance

(pĕn′ĭ-trəns)n. The frequency, under given environmental conditions, with which a specific phenotype is expressed by those individuals with a specific genotype.

penetrance

Penetration The disruption of a surface, as in penetrating–eg, gunshot wounds, hospital-acquired penetration contact due to infected 'sharps', or forcible penetration in rape

pen·e·trance

(pen'ĕ-trăns) The frequency, expressed as a fraction or percentage, of people who are phenotypically affected, among people of an appropriate genotype; factors affecting expression may be environmental, or due to purely random variation; contrasted with hypostasis where the condition has a genetic origin and therefore tends to cause correlation in relatives.

penetrance

The frequency with which a GENE manifests its effect. Failure to do so may result from the modifying effect of other genes or from environmental influences. A single hereditable dominant or recessive characteristic is either penetrant or not. Penetrance is measured as the proportion of individuals in a population with a particular genotype who show the corresponding PHENOTYPE.

penetrance

the percentage of individuals with a particular GENOTYPE that display the genotype in the PHENOTYPE. For example, a dominant gene for baldness is 100% penetrant in males and 0% penetrant in most females, because the gene requires high levels of the male hormone for expression, an example of SEX LIMITATION. Once a gene shows penetrance it may show a range of EXPRESSIVITY of phenotype.

penetrance

The frequency with which the characteristics transmitted by a gene appear in individuals possessing it. Penetrance is represented as the ratio of individuals who carry the gene and express its effects, over the total number of carriers of the gene in a population. Few of the genes in the genome show a high penetrance because environmental factors play a role in development. Examples: familial exudative vitreoretinopathy and neurofibromatosis (type 1 and type 2), which are both inherited as autosomal dominant, have 100% penetrance; about 90% of the children who carry the retinoblastoma gene develop the disease while the gene remains non-penetrant in the remaining 10% of the children. See expressivity; familial exudative vitreoretinopathy.

单词	penetrance
释义	penetrance pen·e·trance P0162700 (pĕn′ĭ-trəns)n. The frequency, under given environmental conditions, with which a specific phenotype is expressed by those individuals with a specific genotype. penetrance (ˈpɛnɪtrəns) n (Genetics) genetics the percentage frequency with which a gene exhibits its effect[C20: from penetr(ant) + -ance, on the model of German penetranz] pen•e•trance (ˈpɛn ɪ trəns) n. the frequency, expressed as a percentage, with which a particular gene produces its effect in a group of organisms. Compare expressivity (def. 2). [1635–45] Penetrance penetrance [′pen·ə·trəns] (genetics) The proportion of individuals carrying a dominant gene in the heterozygous condition or a recessive gene in the homozygous condition in which the specific phenotypic effect is apparent. Also known as gene penetrance. Penetrance a quantitative index of phenotypic variability in the expression of a gene. Penetrance is usually measured as the percent ratio of the number of individuals in whom the gene is expressed to the total number of individuals in whose genotype the gene is present in the homozygous state (for recessive genes) or heterozygous state (for dominant genes). Complete penetrance occurs when a certain gene is expressed in 100 percent of individuals with the appropriate genotype. Penetrance can also be incomplete, in which case it is called variable. Variable penetrance is characteristic of the expressivity of many genes in humans, animals, plants, and microorganisms. For example, certain hereditary diseases of man develop only in a portion of the persons whose genotype contains the anomalous gene; in the remainder, the hereditary predisposition to the disease remains unrealized. Variable penetrance is due to the complexity and multistage nature of the many events that occur between the first actions of a gene on the molecular level and the eventual emergence of a trait. The penetrance of a gene may vary within broad limits, depending on the nature of the surrounding genes within the genotype. Strains of individuals with a given degree of penetrance may be obtained by artificial selection. The average degree of penetrance also depends on environmental conditions. REFERENCES Lobashev, M. E. Genetika, 2nd ed. Leningrad, 1967. Timofeev-Resovskii, N. V., and V. I. Ivanov. “Nekotorye voprosy fenogenetiki.” In the collection Aktual’nye voprosy sovremennoi genetiki. Moscow, 1966. Pages 114–30. V. I. IVANOV penetrance penetrance [pen´ĕ-trans] the frequency with which a heritable trait is manifested by individuals carrying the principal gene or genes conditioning it. pen·e·trance (pen'ĕ-trans), The frequency, expressed as a fraction or percentage, of people who are phenotypically affected, among those of an appropriate genotype (i.e., homozygous or hemizygous for recessives, heterozygous or hemizygous for dominants); for an autosomal dominant disorder, if only a proportion of people carrying the mutant allele display the abnormal phenotype, the trait is said to show incomplete penetrance. If all with the mutant allele show the abnormal phenotype, the trait is said to have complete or full penetrance. See: penetration. penetrance (pĕn′ĭ-trəns)n. The frequency, under given environmental conditions, with which a specific phenotype is expressed by those individuals with a specific genotype. penetrance Penetration The disruption of a surface, as in penetrating–eg, gunshot wounds, hospital-acquired penetration contact due to infected 'sharps', or forcible penetration in rape pen·e·trance (pen'ĕ-trăns) The frequency, expressed as a fraction or percentage, of people who are phenotypically affected, among people of an appropriate genotype; factors affecting expression may be environmental, or due to purely random variation; contrasted with hypostasis where the condition has a genetic origin and therefore tends to cause correlation in relatives. penetrance The frequency with which a GENE manifests its effect. Failure to do so may result from the modifying effect of other genes or from environmental influences. A single hereditable dominant or recessive characteristic is either penetrant or not. Penetrance is measured as the proportion of individuals in a population with a particular genotype who show the corresponding PHENOTYPE. penetrance the percentage of individuals with a particular GENOTYPE that display the genotype in the PHENOTYPE. For example, a dominant gene for baldness is 100% penetrant in males and 0% penetrant in most females, because the gene requires high levels of the male hormone for expression, an example of SEX LIMITATION. Once a gene shows penetrance it may show a range of EXPRESSIVITY of phenotype. penetrance The frequency with which the characteristics transmitted by a gene appear in individuals possessing it. Penetrance is represented as the ratio of individuals who carry the gene and express its effects, over the total number of carriers of the gene in a population. Few of the genes in the genome show a high penetrance because environmental factors play a role in development. Examples: familial exudative vitreoretinopathy and neurofibromatosis (type 1 and type 2), which are both inherited as autosomal dominant, have 100% penetrance; about 90% of the children who carry the retinoblastoma gene develop the disease while the gene remains non-penetrant in the remaining 10% of the children. See expressivity; familial exudative vitreoretinopathy.
随便看	british maritime charitable foundation british maritime law association british maritime technology british market research association british market research bureau british martial arts & boxing association british martial arts federation british martinist order british mass spectrometry society british masters athletic federation british masters championships british match crossbow association british materials handling board british materials handling federation british maternal fetal medicine society british mathematical colloquium british mathematical olympiad british mathematical olympiad subtrust british measurement and testing association british meat education service british meat manufacturers' association british meat nutrition education service british meat processors association british mechanical rights agency british medical acupuncture society