Developmental and epileptic encephalopathy 70 (DEE70) is an epileptic encephalopathy associated with multiple neurological abnormalities and global developmental delay, among other characteristics. It has recently been established that it is caused by a heterozygous variant of the PHACTR1 gene, with currently four cases reported in the literature. This article presents a case report of a patient with DEE70 with a heterozygous variant in the PHACTR1 gene, who also presents a hemizygous variant in the AFF2 gene, associated with FRAXE syndrome. A phenotypic comparison is made between this case and the four other previously reported cases with variants in the PHACTR1 gene. In addition, the possible participation of the PHACTR1 and AFF2 genes in the clinical characteristics of the individual is discussed.