WIPI2 and pathologic nystagmus: Despite the significant phenotypic variability and a limited number of cases, defective WIPI2, similar to other congenital disorders of autophagy, seems to preferentially impact cortical pyramidal neurons and the corticospinal tracts (Family 1 with severe and progressive spasticity) as well as cerebellar Purkinje cells (nystagmus and the inferior cerebellar vermis hypoplasia in all families, and ataxic gait in Case F2-IV:3 and the affected individuals reported by Jelani et al.9).