Frameshift mutation, microsatellites and mismatch repair.

The structure of eukaryotic DNA, with its repeated sequences, makes base addition and loss a major obstacle to the maintenance of genetic stability. As compared to the bacteria, much of the mismatch repair capacity of the eukaryotic cell must be devoted to the surveillance of frameshift changes. Any alteration in the activity of proteins which recognize frameshifts or which hold the DNA in place during replication is likely to result in genomic instability.