Hereditary Cancer and Genetic Testing

Other medical concerns for people with inherited PMS2 mutations

Children who inherit an PMS2 mutation from both their mother and their father can have a rare syndrome known as “constitutional mismatch repair deficiency (CMMRD).” CMMRD can cause high risks of various cancers in childhood and young adulthood. Children with CMMRD syndrome may have blood (hematological) and brain/central nervous system tumors and colorectal and other cancers that are typically seen in Lynch syndrome patients at a later age. Many, but not all CMMRD patients show features that resemble neurofibromatosis, a genetic disorder that causes tumors to form on nerve tissue, particularly harmless, light brown “café au lait” spots on the skin. Both parents must have an PMS2 mutation for a child to have CMMRD. Couples where one partner has a known PMS2 mutation may wish to speak with a genetic counselor about testing the other partner prior to having children.

There are options using assisted reproduction technology and preimplantation genetic diagnosis for parents to select embryos that are free of inherited PMS2 mutations.