ATN1 and myotonic dystrophy type 1: We inferred neutral evolution for the three other microsatellites causative of the trinucleotide expansion disorders SCA3 (ATXN3) [112], dentatorubral-pallidoluysian atrophy (DRPLA) (ATN1) [113], and myotonic dystrophy type 1 (DM1) (DMPK) [114].