The 3 patients with no SIL1 mutation (Patients 25, 26, and 27) and the 9 genetically unexamined patients showed clinical features indistinguishable from the patients with SIL1 mutations, including cerebellar signs with cerebellar atrophy on brain images, intellectual disability, congenital cataracts, and muscle weakness. Here, SIL1 is linked to early-onset non-syndromic cataract.