Bi-allelic PRMT9 loss-of-function variants cause a syndromic form of intellectual disability

Bi-allelic loss-of-function variants in protein arginine methyltransferase 9 (PRMT9) cause a neurodevelopmental disorder with variable severity. Affected individuals have mild to severe intellectual disability, global developmental delay, autism spectrum disorder, epilepsy, and hypotonia. Functional studies on patients’ cells reveal a possible functional impact on ciliary functions.