In this study [256], the authors provided strong evidence that loss of functional SLC25A46 could be the cause of motor neuron degeneration, suggesting a novel classification for SLC25A46-associated PCH1 as PCH1D in order to distinguish it from other PCH1 subtypes characterized by mutations in other genes involved in RNA metabolism and gene expression [256]. Here, VRK1 is linked to pontocerebellar hypoplasia, type 1D.