SETX and juvenile amyotrophic lateral sclerosis: One prominent example is SETX that encodes a DNA/RNA helicase and when mutated causes a recessive form of spinocerebellar ataxia (OMIM 606002) and a dominant form of juvenile amyotrophic lateral sclerosis (OMIM 602433) (Chen et al. 2004; Moreira et al. 2004).