dissenting.
I respectfully dissent.
The law is settled, as the principal opinion correctly observes, that statutes of limitations are procedural in nature. Wentz v. Price Candy Co., 352 Mo. 1, 175 S.W.2d 852 (1944). The law is equally clear that statutes affecting procedure are presumed to apply retroactively unless a contrary intention is expressed by the legislature. Scheidegger v. Greene, 451 S.W.2d 135, 137 (Mo.1970); State ex rel. Clay Equipment Corp. v. Jensen, 363 S.W.2d 666, 669 (Mo. banc 1963). This rule applies to laws that shorten the statute of limitations applicable to an existing cause of action, provided that a reasonable period of time is permitted to bring the action. Rabin v. Krogsdale, 346 S.W.2d 58, 60 (Mo.1961); Hartvedt v. Maurer, 359 Mo. 16, 220 S.W.2d 55, 58 (1949). Applying these rules of construction, every person who had an unfiled medical malpractice claim at the time § 516.105, RSMo 1978, went into effect has two years from the effective date of the statute or until his or her twelfth birthday, whichever occurs last, in which to bring the action. To hold otherwise, as the principal opinion does, is to deny the retroactive application of this procedural statute and to tacitly overrule existing law.