Table 1.

Repeat expansions causing neurologic disease

• CAG – at least 10 diseases (Huntington disease, spinal and bulbar muscular atrophy, dentatorubral-pallidoluysian atrophy and seven SCAs)

• CGG – fragile X, fragile X tremor ataxia syndrome, other fragile sites (GCC, CCG)

• CTG – myotonic dystrophy type 1, Huntington disease-like 2, spinocerebellar ataxia type 8, Fuchs corneal dystrophy

• GAA – Friedreich ataxia

• GCC – FRAXE mental retardation

• GCG – oculopharyngeal muscular dystrophy

• CCTG – myotonic dystrophy type 1

• ATTCT – spinocerebellar ataxia type 10

• TGGAA – spinocerebellar ataxia type 31

• GGCCTG – spinocerebellar ataxia type 36

• GGGGCC – C9ORF72 frontotemporal dementia/amyotrophic lateral sclerosis

• CCCCGCCCCGCG – EPM1 (myoclonic epilepsy)