NFIX and Intellectual disability: However, it should be noted that CC2D1A is a recessive intellectual disability gene, while NACC1 is associated with a dominant disease caused by a recurrent missense variant, so detailed studies about the involvement of this genes, as well as the other genes located in the deleted 19p region of our patient, besides NFIX, could accurately define the genotype–phenotype correlations linked to 19p deletions.