Final answer:
A mutation in a gene coding for a mismatch repair protein causes elevated mutation rates because errors made during DNA replication are not efficiently corrected. This leads to an accumulation of permanent mutations in the genetic material, potentially causing disorders such as cancer.
Step-by-step explanation:
A mutation in one of the genes that codes for a protein needed for mismatch repair can lead to elevated mutation rates in other genes because these repair proteins are crucial for correcting errors that occur during DNA replication. Without functional mismatch repair enzymes, replication errors that include incorrect nucleotide pairing may not be corrected, leading to permanent changes in the DNA sequence, or mutations. These mutations can accumulate over time and can lead to serious consequences like cancer. This is because the DNA polymerases' proofreading abilities are not perfect, and the cells rely on mismatch repair mechanisms to fix the mistakes that were initially missed.