Due to the specificity of the described signs and symptoms, a variety of diseases should be considered as a differential diagnosis of PCH, including congenital disorder of glycosylation type Ia, CASK-related disorders, Tubulin defects, mutations in RELN and VLDLR genes, Walker-Warburg syndrome, Muscle eye brain disease, Fukuyama muscular dystrophy, pediatric-onset spinocerebellar ataxia, SMA, Joubert’s syndrome, and Dandy-Walker malformation. The gene discussed is CASK; the disease is proximal spinal muscular atrophy.