Genetic testing results — Challenge to results.
RCW 26.26A.325
in effect(1) Subject to a challenge under subsection (2) of this section, an individual is identified under this chapter as a genetic parent of a child if genetic testing complies with RCW 26.26A.300 through 26.26A.355 and the results of the testing disclose: (a) The individual has at least a ninety-nine percent probability of parentage, using a prior probability of 0.50, as calculated by using the combined relationship index obtained in the testing; and (b) A combined relationship index of at least one hundred to one. (2) An individual identified under subsection (1) of this section as a genetic parent of the child may challenge the genetic testing results only by other genetic testing satisfying the requirements of RCW 26.26A.300 through 26.26A.355 which: (a) Excludes the individual as a genetic parent of the child; or (b) Identifies another individual as a possible genetic parent of the child other than: (i) The woman who gave birth to the child; or (ii) The individual identified under subsection (1) of this section. (3) Except as otherwise provided in RCW 26.26A.350 , if more than one individual other than the woman who gave birth is identified by genetic testing as a possible genetic parent of the child, the court shall order each individual to submit to further genetic testing to identify a genetic parent.
(1) Subject to a challenge under subsection (2) of this section, an individual is identified under this chapter as a genetic parent of a child if genetic testing complies with RCW 26.26A.300 through 26.26A.355 and the results of the testing disclose:
(a) The individual has at least a ninety-nine percent probability of parentage, using a prior probability of 0.50, as calculated by using the combined relationship index obtained in the testing; and
(b) A combined relationship index of at least one hundred to one.
(2) An individual identified under subsection (1) of this section as a genetic parent of the child may challenge the genetic testing results only by other genetic testing satisfying the requirements of RCW 26.26A.300 through 26.26A.355 which:
(a) Excludes the individual as a genetic parent of the child; or
(b) Identifies another individual as a possible genetic parent of the child other than:
(i) The woman who gave birth to the child; or
(ii) The individual identified under subsection (1) of this section.
(3) Except as otherwise provided in RCW 26.26A.350 , if more than one individual other than the woman who gave birth is identified by genetic testing as a possible genetic parent of the child, the court shall order each individual to submit to further genetic testing to identify a genetic parent.
Source: WA Statutes (Official Site)URL: https://app.leg.wa.gov/RCW/default.aspx?cite=26.26A&full=trueFetched: 6/29/2026