TREX1 and Cerebral visual impairment: They include a pathogenic TREX1 single nucleotide variant (SNV) in a patient with intellectual disability [38] and a 3.1-Mb microdeletion of the 3p21.31 region including TREX1 in a patient with cortical blindness, cleft lip, central nervous system abnormalities, and developmental delay [39], although causality of such variants has not been established.