VRK1 and motor neuron disorder: The first detailed description of anterior horn cell disease with pontocerebellar hypoplasia in infants was provided by Goutieres in 1977, and since then recessive variants in five genes have been identified as causes of PCH1, including VRK1, EXOSC3, EXOSC8, EXOSC9 and SLC25A46 [1,5,6].