PGAP1 and Intellectual disability: Based on our mapping results, exome sequencing data and functional experiments that proved pathogenicity of the mutation, the previous reports on intellectual disability caused by mutations in the GPI synthesis pathway, and the mouse models that clearly show an association between the disruption of Pgap1 and abnormalities of brain, we consider the deletion of leucine197 to be causative for the severe non-specific autosomal recessive intellectual disability in our examined patients of family MR079.