Mo. Rev. Stat. § 490.370
In any deed conveying real estate heretofore or hereafter made, by any person or persons claiming to be the heir or heirs of some other person, if a recital shall have been or shall be made in said deed, showing or tending to show such heirship, or kinship, or if there shall have been, or shall be, an affidavit made in connection with said deed by one or more of the makers thereof, and attached to said deed, with a recital therein, showing, or tending to show, such heirship or kinship, such recital in such deed or such affidavit or both or the record thereof, may be read in evidence as the testimony of the persons making such deed or affidavit, in the trial of any suit in any court in this state wherein the title to the real estate described in said deed, or any part thereof, is involved or called in question in any manner; provided, however, that the maker of such deed and affidavit shall be dead or absent from the state or otherwise disqualified from testifying in suit, and, that before such recital or affidavit shall be received in evidence it must be shown that the said deed was filed for record, in the office of the recorder of deeds of the county where said real estate, or some part thereof, is situated, at least five years before the filing of the suit wherein such recital, or affidavit, is offered in evidence; and provided further, that the same person claiming title to said real estate, or some part thereof, or interest therein, or some person through whom he claims under or through said deed, shall have paid taxes on the land described in said deed, or some part thereof, or interest therein, for three different years before the filing of such suit.
§ 490.370, RSMo