Phenotype restoration through genotype change but without true genotype restoration.
Pseudoreversions are mutations that restore a phenotype lost to a previous mutation, but does so without actually correcting the original mutation. In a sense, then, pseudoreversions are compensatory mutations in which phenotype to some greater or lesser degree is restored (versus simply fitness restored).
Assuming the phenotype restored in fact is beneficial, then pseudoreversions can be viewed as a type of beneficial mutation, as indeed can also compensatory mutations. In addition, pseudoreversions along with compensatory mutations generally can, if compenstation is , be viewed as examples of epistasis.
Contrast with true reversion mutations, which represent phenotype restoration through genotype change with true genotype restoration. See also .