 As it involves the repeat of four nucleotides, it is not a trinucleotide repeat disorder, but rather a tetranucleotide repeat disorder.The repeat expansion for DM2 is much larger than for DM1, ranging from 75 to over 11,000 repeats.Unlike in DM1, the size of the repeated DNA expansion in DM2 does not appear to make a difference in the age of onset or disease severity.