Mo. Rev. Stat. § 469.010
Any individual to whom property or an interest therein is donatively transferred by any means, including a transfer resulting from another disclaimer, may disclaim all or any portion of the transfer. Unless the terms of the transfer otherwise provide, the disclaimer shall cause the terms of the transfer to be applied to the disclaimed transfer and to any future interests taking effect thereafter as if the disclaimant had died immediately before the transfer. The presumption of a disclaimant's death does not prevent recognition of the disclaimant's later born children and their issue, assuming they have rights after all proper acceleration has taken place, nor does it prevent recognition of future and other interests of the disclaimant which are not disclaimed. For all purposes the disclaimed interest is deemed to have passed directly from the transferor to the ultimate taker or takers and is not subject to the claim of any creditor of the disclaimant. A disclaimed portion of a transfer passes to the same ultimate taker or takers and in the same proportions as in the case of a disclaimer of all of the transfer.
§ 469.010, RSMo