PTPA and neurodevelopmental disorder: Specifically, PP2A-related neurodevelopmental disorders are characterized by mutations in PPP2R1A (Aα), PPP2CA (Cα), PPP2R2C (B55γ), PPP2R5B (B56β), PPP2R5C (B56γ), and PPP2R5D (B56δ), with most patients and mutations, so far, found in PPP2R5D (Figures 3A–C).