nonpenetrance

non·pen·e·trance

(non-pen'ĕ-trants), The state in which a genetic trait, although present in the appropriate genotype (that is, homozygous, hemizygous, or heterozygous according to the state of dominance and mode of inheritance), fails to manifest itself in the phenotype because of modifying factors. Compare: hypostasis.

non·pen·e·trance

(non-pen'ĕ-trăns) The state in which a genetic trait, although present in the appropriate genotype, fails to manifest itself in the phenotype because of nongenetic mechanisms.
Compare: hypostasis