Houge-Janssens Syndrome 1, also known as intellectual disability-macrocephaly-hypotonia-behavioral abnormalities syndrome, is related to ppp2r5d-related intellectual disability and houge-janssens syndrome 2. An important gene associated with Houge-Janssens Syndrome 1 is PPP2R5D (Protein Phosphatase 2 Regulatory Subunit B'Delta), and among its related pathways/superpathways is Lissencephaly gene (LIS1) in neuronal migration and development. Affiliated tissues include heart and eye, and related phenotypes are macrocephaly and global developmental delay