Nonpenetrance

Part of speech: noun

Definitions

1. The condition in which an individual carries a genetic mutation but does not display the expected traits or symptoms ; the absence of observable effects despite possessing a certain genotype ; the phenomenon where a gene is present but its characteristic does not manifest visibly or phenotypically
2. The state of a gene failing to express its associated trait in an organism even though the gene is inherited ; possessing a hereditary variant without exhibiting usual signs or characteristics ; a genetic scenario where expected traits remain unapparent despite gene presence
3. A genetic circumstance wherein an inherited mutation does not result in visible or detectable features ; lack of phenotypic expression of a gene despite its presence in the DNA ; the occurrence of an individual carrying a gene but showing no manifestation of its associated condition

Etymology: "Nonpenetrance" is a plain formation: the prefix "non-" ("not") attached to "penetrance," so the word literally names the absence of penetrance. The prefix is the familiar English one from Latin "non," meaning "not," and it is productive enough to attach to almost any noun. The base word carries the genetics. "Penetrance" is a term from Mendelian genetics, used for the proportion of individuals carrying a particular gene variant who actually display the trait that variant is associated with. A gene with full penetrance always shows its effect; one with reduced penetrance sometimes does not. Nonpenetrance therefore describes the extreme case, where a person inherits the variant and yet shows no sign of it. This kind of compound is typical of technical vocabulary, built from existing English parts to name a precise concept rather than inherited from older usage. Its meaning is fixed by the scientific context in which it is used.

Synonyms: incomplete penetrance, penetrance failure

Antonyms: penetrance