We don't have synonyms for premutation yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are reputation, permutation and refutation.
(n) :
A nucleotide sequence variation that is not enough to be classed as a mutation (for example, does not affect protein expression enough to produce clinical symptoms) but nonetheless represents an unusual variant that is predisposed to still greater variation in future cell divisions (that is, predisposed to leading to a mutation).
(n) :
A nucleotide sequence variation that is not enough to be classed as a mutation (for example, does not affect protein expression enough to produce clinical symptoms) but nonetheless represents an unusual variant that is predisposed to still greater variation in future cell divisions (that is, predisposed to leading to a mutation).