Interestingly, this family shares several phenotypic features with our case such as global developmental delay, intellectual disability, hyporeflexia, cerebellar hypoplasia, supratentorial cerebellar volume loss, hypoplasia of corpus callosum, etc. Some features previously attributed to phenotypic expansion of ALKBH8 are now better explained by the TUBB2B variants (Figure 2B). This evidence concerns the gene TUBB2B and Global developmental delay.