STATH and neurodegenerative disease: STR variants have been reported as the cause of a series of neurodegenerative diseases, including myotonic dystrophies (DM1and DM2), fragile X tremor/ataxia syndrome (FXTAS), some spinocerebellar ataxias (SCAs), and chromosome 9 open reading frame 72 (C9ORF72)-related amyotrophic lateral sclerosis (ALS) [21].