RBMX functional retrocopy safeguards brain development in a species-dependent context.
It is demonstrated that RBMX and RBMXL1 share protein and RNA partners and act redundantly in brain development, with RBMXL1 buffering the impact of RBMX deficiency and establishing RBMXL1 as a functional paralog of RBMX that is likely buffering deleterious variation in a context- and dosage-dependent manner.