This technology may be applicable to other repeat expansions that are known to contain heterogeneous repeats at disease loci, including ATXN8OS in SCA8 [3], BEAN in SCA31 [4], NOP56 in SCA36 [28], DAB1 in SCA37 [6], FXN in Friedreich ataxia [29], RFC1 in AR-CANVAS [17], SAMD12, TNRC6A and RAPGEF2 in BAFME [13], STARD7 in BAFME2 [14], MARCHF6 in BAFME3 [15], YEATS2 in BAFME4 [16], DMPK in DM1 [30], and TCF4 in Fuchs endothelial corneal dystrophy (FECD) [31]. The gene discussed is TCF4; the disease is myotonic dystrophy type 1.