(redirected from phenocopies)
Also found in: Dictionary, Medical.
Related to phenocopies: pleiotropy, genocopy


The nonhereditary alteration of a phenotype to a form imitating a mutant trait; caused by external conditions during development.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



a nonhereditary change in a phenotype, induced by specific environmental conditions and mimicking of some known hereditary change, or mutation, as exhibited in the phenotype. For example, nonhereditary teratism, or monstrosities, may be induced in the genetically normal embryos and larvae of some insects by various means, including high temperatures and vaporized ether; examples of such monstrosities, which may be observed in adult individuals, are a change in the number of legs or wings or the transformation of antennae into legs. These monstrosities are phenocopies of similar but hereditary changes that normally develop, in the absence of any external influence, in a number of mutant insect strains.

Phenocopies of various mutuations may be experimentally induced in other species of animals and plants as well. As a rule, the possible range of such phenocopies is not determined by the nature of the operative factor, but rather by the stage of development of the experimental organism. Presumably, some external factor that produces phenocopies in normal individuals interferes with the activity of the corresponding normal genes, resulting in the appearance of a mutant phenotype. The study of phenocopies is thus an important field of inquiry for phenogenetic research.


Lobashev, M. E. Genetika. Leningrad, 1967.
Goldschmidt, R. B. Physiological Genetics. New York, 1938.


The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
The term Brugada phenocopies does not cover abnormal electrocardiogram patterns that are induced by sodium channel blockers (2).
An Fgf8 mouse mutant phenocopies human 22q11 deletion syndrome.
Ses Phenocopies Compromised Calcineurin Signaling Pathway in C.
METHODS AND RESULTS: Golgi analysis of hippocampi from weanling rats confirmed that developmental exposure via the maternal diet to NDL PCB-95 (2,2',3,5'6-pentachlorobiphenyl), a potent RyR potentiator, phenocopies the dendrite-promoting effects of A1254.
The possibility that more subtle dysmorphic features could aid in a diagnosis of FAS or partial FAS in the absence of information on alcohol exposure in pregnancy (after eliminating genetic disorders otherwise appearing as phenocopies) currently is being investigated by an international consortium funded by NIAAA.
In addition, it has been reported that these inhibitory activities of calystegines [B.sub.2] and [C.sub.1] could produce phenocopies of the genetic lysosomal storage (Gaucher's and Fabry's) diseases.
The trouble with phenocopies: are those testing negative for a family BRCA1/2 mutation really at population risk?
Phenocopies in BRCA1 and BRCA2 families: evidence for modifier genes and implications for screening.
As well, there is a lack of correspondence between the inherited genotype(s) and the resultant phenotype(s), which may be due to incomplete penetrance of predisposing loci or to phenocopies, that is disease that develops in the absence of apparent genetic risk factors.
Early death of parents, the varying ages at onset and phenocopies may partly account for this.