PCDH11X and Intellectual disability: The common region only includes the genes PCDH11X, NAP1L3, and FAM133A, none of which has been associated with a clinical phenotype so far, although PCDH11X is thought to play an important role in the development of intellectual disability given its high expression in the nervous system and its involvement in intercellular communication, synaptic plasticity, and verbal ability [19]