Mutations in PRDM15, which codes for PRDF1 (positive regulatory domain I–binding factor 1) and RIZ1 (retinoblastoma protein–interacting zinc finger gene 1) homology domain–containing protein 15 (PRDM15), result in a syndromic form of HPE also known as the Galloway–Mowat syndrome (GAMOS) (Mzoughi et al., 2020; Mann et al., 2021). This evidence concerns the gene PRDM15 and holoprosencephaly.