From this genetic information, the patient was diagnosed with CMMRD, indicating compound heterozygous variants in MSH6. This result suggested that loss of MSH2 protein expression in tumor tissue was probably due to secondary acquired somatic changes in MSH2. Parental and sibling genetic testing confirmed the patient was the biological daughter of her parents and an offspring of a non-consanguineous marriage. The gene discussed is MSH6; the disease is neoplasm.