A nonsense mutation, c.115 C>T p.Gln39X, in the conserved N-terminal domain of INPP4A leads to intellectual disability without brain malformation (Banihashemi et al., 2020), while homozygous genomic deletion of 1770 bp within the INPP4A gene causes myoclonic epilepsy, microcephaly and atrophy of the cerebellum (Sheffer et al., 2015). This evidence concerns the gene INPP4A and microcephaly.