Blue Cross & Blue Shield of MississippiAll Plans · Coverage · Medical Policy · Genetics, Neurology, PediatricsMedium impact
Genetic Testing for Rett Syndrome
Effective date
Not stated in the notice
Identified
Jun 20, 2026
Summary
Genetic testing for Rett syndrome-associated genes (MECP2, FOXG1, or CDKL5) may be considered medically necessary to establish a genetic diagnosis of Rett syndrome in a child with developmental delay and signs or symptoms of Rett syndrome, when a definitive diagnosis cannot be made without genetic testing. Targeted testing for a known familial variant may be considered medically necessary to determine carrier status of first-degree female relatives, a mother or a sister, of an individual with Rett syndrome. All other indications, including routine carrier testing and testing of asymptomatic family members to determine future risk, are considered investigational. The policy was reviewed on 01/26/2026 with its policy statements unchanged, and ICD-9 diagnosis codes were removed from the code reference.
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01Billing team: Bill genetic testing for Rett syndrome-associated genes for a child only when there is developmental delay and signs or symptoms of Rett syndrome and a definitive diagnosis cannot be made without genetic testing.
02Bill targeted testing for a known familial variant only to determine carrier status of a first-degree female relative, a mother or a sister, of an individual with Rett syndrome.
03Do not bill routine carrier testing, including preconception or prenatal testing in persons with negative family history, or testing of asymptomatic family members to determine future risk, as medically necessary, because the policy considers these investigational.
Codes mentioned
8130281303813048140481406F84.2Z31.430
Original notice
Genetic Testing for Rett Syndrome
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