Low-density lipoprotein receptor-related protein 2 (LRP2), aka megalin, mutations lead to the protein loss of function, underlying an autosomal recessive disorder, the Donnai-Barrow syndrome (Kantarci et al., 2007), characterized by several CNS functional defects, particularly myopia and ocular complications, sensorineural hearing loss, mild to moderate intellectual disability, development delay and, in some cases, agenesis of the corpus callosum (Pober et al., 2009), and other symptoms such as specific craniofacial features, intestinal and heart abnormalities. This evidence concerns the gene LRP2 and Intellectual disability.