C9orf72 and myotonic dystrophy type 1: We first identified translation initiation codons upstream of repeats in the following genes in which RAN translation is known to occur: C9orf72 (associated with amyotrophic lateral sclerosis and frontotemporal dementia), FMR1 (associated with fragile X and fragile X-associated tremor/ataxia syndrome), DM1 (associated with myotonic dystrophy type 1), and HDL2 (associated with Huntington disease-like 2) genes.