Of interest, a further individual has been reported with compound heterozygous missense variants in CYP26B1 (p.[(Glu177Lys)];[(His175Gln)]) and biallelic variations in the NAGLU. Although the phenotype (epilepsy, early onset epileptic encephalopathy, hypermyotonia, skull deformity, dilatation of the lateral ventricles and premature closure of fontanel) was different from the previous cases, it was attributed to the CYP26B1 variants despite the p.(Glu177Lys) variant being previously classified as likely pathogenic and an absence of functional data for both variants (Li et al. 2018). This evidence concerns the gene NAGLU and genetic developmental and epileptic encephalopathy.