While some of the ELOVL4 mutations in humans are reported to only affect the retina and cause STGD3 without any other neurological or skin pathologies, other mutations affect the brain and/or skin, leading to spinocerebellar ataxia 34 (SCA34) and Erythrokeratodermia variabilis (EKV) without any reported retina degeneration (16, 26, 28, 29, 30, 31, 32, 33, 34, 35). This evidence concerns the gene ELOVL4 and spinocerebellar ataxia type 34.