Hereditary nonpolyposis colorectal cancer (HNPCC) is an inherited dominant autosomal disorder caused by defects in the mismatch repair (MMR) mechanism that increases the risk of cancer in the colon and endometrium. The MSH2 gene is part of MMR, and when defective, can terminate its function, leading to an increased mutation rate and a higher development for HNPCC. Not all mutations lead to a defective MSH2, but to determine which single nucleotide polymorphism (SNP) is critical, an investigation was lead on how mutations in the gene MSH2 affects the mutation rate in yeast. Using three E.coli strains to produce more plasmids, PCR and restriction enzyme digestion was enacted to verify the identities of the empty vector, wild type and mutated MSH2 plasmids. Yeast cells were then transformed with the mutated plasmid carrying the mutation G693D, which was analyzed using ApE and Clustal Omega. After completing an FOA assay, the MSH2 alleles grew, signifying a high mutation rate and a likely mutation that can lead to the arise of HNPCC because G693D causes a defective MMR system. Classifying which mutations are harmful and which are benign can aid in detecting patients that have a higher risk for HNPCC.
