AP5Z1 and Cognitive impairment: Finally, we report 4 mutations that cluster within genes highly expressed in the brain and already associated to developemental cognitive impairment and intellectual disability (TNR [p.S497L], AP5Z1[p.T769R], SOX5 [p.G346R], ZNF142 [p.R862L])33 (https://www.omim.org/) (Table S3, Fig. 2E).