- 1. Appearance before the appointed time of a periodic symptom or sign. 2. Progressively earlier age of manifestation of a hereditary disease in successive generations; may be factitious (because of heightened awareness to early signs of the disease or because they are more conspicuous in the young) or authentic (because of progressive loss of epistatic and modifier genes by recombination and segregation, or because of expansion of unstable alleles in successive generations). 3. An increase in the severity of a phenotype in successive generations of a family, often associated with an increase in the number of trinucleotide repeats in a causative gene (e.g., fragile X syndrome, myotonic dystrophy, Huntington disease).
* * *an·tic·i·pa·tion (.)an-.tis-ə-'pā-shən n1) occurrence (as of a disease or symptom) before the normal or expected time2) mental attitude that influences a later response
* * *an·ti·ci·pa·tion (an-tis″ĭ-paґshən) 1. the manifestation of a hereditary disease at a progressively earlier age in successive generations; it can be caused by expansion of triplet repeats in some genetic disorders, but can also be an artifact arising from the greater likelihood of detecting a mildly affected parent having a severely affected child, rather than the reverse, or from other ascertainment bias. 2. looking forward to future events, experiences, or emotions, preexperiencing them; it can be used as a defense mechanism.
Medical dictionary. 2011.