Missouri Revised Statutes Title XXXI. Trusts and Estates of Decedents and Persons Under Disability § 469.090. Special rules for interests under old transfers

(1) Such interest is subject to disclaimer in whole or in part for a reasonable time after the disclaimant has knowledge of the existence of the transfer;

(2) If the interest has vested before the disclaimant's eighteenth birthday, and the disclaimant has knowledge of the existence of the transfer before the disclaimant's eighteenth birthday, such interest is subject to disclaimer in whole or in part until a reasonable time elapses after the disclaimant's eighteenth birthday, except that a written acceptance by the disclaimant's representative shall constitute an acceptance of any portion of the interest.