PPP2R1A and Hogue-Janssens syndrome 1: Recently, associations between de novo missense pathogenic variants of PPP2R5D, PPP2R1A, and PPP2CA have been reported, leading to autosomal-dominant forms of intellectual disability (MRD35 (OMIM#616355), MRD36 (OMIM#616362), and NDLBA (OMIM#618354), respectively, also known as Houge-Janssen syndrome 1,2, and 3) [1,4].