Genetic anticipation is characteristic of:

Genetic Anticipation refers to the progressive increase in severity of an illness as it manifests in its transmission from parent to child, occurring in a more severe form and at an earlier age with succeeding generations. It is more commonly seen in trinucleotide repeat disorders. Classical examples are Huntington's Disease - CAG Myotonic Dystrophy - CTG Dyskeratosis congenita - TTAGGG (telomere repeat sequence) Fragile X syndrome - CGG Crohn's disease Behcet's disease Ref: Genetic Instabilities and Neurological Diseases, Second Edition, edited by Robe D. Wells, Tetsuo Ashizawa, 2nd Edition, Page 56.