The implication of variants of EIF5A or DHPS in human neurodevelopmental disorders is not surprising in view of the fact that variants in a number of other factors in the translation machinery such as alanyl tRNA synthetase and eukaryotic translation elongation factors 2 (EF2) and 1a2 (EF1a2) have been associated with neurodevelopmental disorders (34). This evidence concerns the gene DHPS and neurodevelopmental disorder.