In addition, the authors define two other duplications reported in public databases: a 720 Kb de novo duplication that contained a full copy of PCYT1B, POLA1 and ARX genes, identified in a boy with syndromic ID (case 5, reported by DECIPHER https://www.deciphergenomics.org/, accessed on 31 January 2022); and a 290 Kb duplication covering partial POLA1 and ARX genes, identified in a patient with developmental delay (reported by the ISCA consortium; case 6; Table 1). Here, ARX is linked to Global developmental delay.