latent carrier

la·tent car·ri·er

a person, typically a prospective parent, bearing the appropriate genotype of a trait (homozygous for recessive, homozygous or heterozygous for dominant, hemizygous or homozygous for X-linked) that manifests the trait only under certain conditions, for example, age, an environmental insult, etc.

la·tent car·ri·er

(lā'tĕnt kar'ē-ĕr) A person, typically a prospective parent, bearing the appropriate genotype of a trait (homozygous for recessive, homozygous or heterozygous for dominant, hemizygous or homozygous for X-linked) that manifests the trait only under certain conditions (e.g., age, an environmental insult).