COL4A1 and Cerebellar atrophy: Individuals with COL4A1/2 were also reported to manifest with schizencephaly (8% [24/290] of individuals with COL4A1 and 13% [4/31] with COL4A2) and cerebellar atrophy (5% [14/290] of individuals with COL4A1 and 3% [1/31] with COL4A2).