Penetrance
The likelihood a given gene will result in disease. For example, if half (50%) of the people with the neurofibromatosis (NF) gene have the disease NF, the penetrance of the NF gene is 0.5.
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The frequency, expressed as a fraction or percentage, of individuals who are phenotypically affected, among persons of an appropriate genotype (i.e., homozygous or hemizygous for recessives, heterozygous or hemozygous for dominants); for an autosomal dominant disorder, if only a proportion of individuals carrying the mutant allele display the abnormal phenotype, the trait is said to show incomplete p.. If all with the mutant allele show the abnormal phenotype, the trait is said to have complete or full p.. See penetration.
- genetic p. (pen′e-trans) the extent to which a genetically determined condition is expressed in an individual.

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pen·e·trance 'pen-ə-trən(t)s n the proportion of individuals of a particular genotype that express its phenotypic effect in a given environment compare EXPRESSIVITY

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n.
the frequency with which the characteristic controlled by a gene is seen in the individuals possessing it. Complete penetrance occurs when the characteristic is seen in all individuals known to possess the gene. If a percentage of individuals with the gene do not show its effects, penetrance is incomplete. In this way a characteristic in a family may appear to 'skip' a generation.

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pen·e·trance (penґə-trəns) [L. penetrare to enter into] in genetics, the frequency of expression of a genotype under defined conditions. If it is less than 100 per cent, the trait is said to exhibit reduced penetrance or lack of penetrance.

Medical dictionary. 2011.

Look at other dictionaries:

  • Penetrance — is a term used in genetics describing the proportion of individuals carrying a particular variation of a gene (an allele or genotype) that also express a particular trait (the phenotype). For example, known mutations in the gene responsible for… …   Wikipedia

  • Penetrance — Pénétrance La pénétrance, en génétique, est la portion d individus possédant un génotype donné qui exprime le phénotype correspondant. La pénétrance d une maladie génétique est de 100 % si cette maladie s exprime dès que les conditions… …   Wikipédia en Français

  • pénétrance — [ penetrɑ̃s ] n. f. • mil. XXe; de pénétrer ♦ Biol. Degré de régularité avec lequel un gène produit son effet spécifique parmi ses porteurs, dans une population. ● pénétrance nom féminin Pourcentage des membres d une famille dont le patrimoine… …   Encyclopédie Universelle

  • Penetrance — Pen e*trance, Penetrancy Pen e*tran*cy, n. The quality or state of being penetrant; power of entering or piercing; penetrating power of quality; as, the penetrancy of subtile effluvia. [1913 Webster] …   The Collaborative International Dictionary of English

  • penetrance — penetrance. См. проявление гена. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • penetrance — [pen′i trəns] n. [< PENETR(ATE) + ANCE] Genetics the degree of regularity with which a gene produces its specific effect in its carriers in a population …   English World dictionary

  • Pénétrance — La pénétrance, en génétique, est la portion d individus possédant un génotype donné qui exprime le phénotype correspondant. La pénétrance d une maladie génétique est de 100 % si cette maladie s exprime dès que les conditions génétiques sont… …   Wikipédia en Français

  • penetrance — n. the frequency with which the characteristic controlled by a gene is seen in the individuals possessing it. Complete penetrance occurs when the characteristic is seen in all individuals known to possess the gene. If a percentage of individuals… …   The new mediacal dictionary

  • penetrance — noun Etymology: International Scientific Vocabulary, from Latin penetrare Date: 1934 the proportion of individuals of a particular genotype that express its phenotypic effect in a given environment …   New Collegiate Dictionary

  • penetrance — The proportion of individuals with a specific genotype who express that character in the phenotype …   Dictionary of molecular biology

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