Mo. Rev. Stat. § 516.270
516.270 Disability not to avail, unless.
516.270. Disability not to avail, unless. — No person shall avail himself of any disability herein enumerated, unless such disability existed at the time his right of action or of entry accrued.
(RSMo 1939 § 1030) Prior revisions: 1929 § 878; 1919 § 1333; 1909 § 1904