Constitutional mismatch fix deficiency (CMMRD) syndrome is a scarce problem that significantly improves the risk of building one or more styles of most cancers in kids and younger adults. The cancers that most generally happen in CMMRD syndrome are cancers of the (significant intestine) and rectum (collectively referred to as colorectal most cancers), brain, and blood (leukemia or lymphoma).

Almost all men and women with CMMRD syndrome build most cancers right before age 18, usually in late childhood. The age of diagnosis varies relying on the most cancers sort brain cancers, leukemia, and lymphomas have a tendency to happen at youthful ages than colorectal most cancers in men and women with CMMRD syndrome. It is estimated that twenty to forty per cent of men and women with CMMRD syndrome who build most cancers will build an additional most cancers afterwards in everyday living.

People today with CMMRD syndrome may perhaps build multiple noncancerous (benign) growths (adenomas) in the colon that are most likely to turn out to be cancerous (malignant) in excess of time. Brain cancers in CMMRD syndrome typically include certain cells referred to as glial cells, leading to gliomas or glioblastomas. The most prevalent blood most cancers in CMMRD syndrome is referred to as which impacts white blood cells. Other cancers that can happen in CMMRD syndrome involve cancers of , , or uterine lining ().

Numerous men and women with CMMRD syndrome build features similar to those people that happen in a affliction referred to as neurofibromatosis sort one. These features involve variations in pores and skin coloring (pigmentation), which are characterized by one or more flat patches on the pores and skin that are darker than the surrounding location (). Some affected folks have freckling or patches of pores and skin that are unusually mild in coloration (hypopigmented). Seldom, men and women with CMMRD syndrome will build a characteristic of neurofibromatosis sort one referred to as Lisch nodules, which are benign growths that typically surface in the coloured part of the eye (the iris). Lisch nodules do not interfere with vision. Some men and women with CMMRD syndrome are originally misdiagnosed with neurofibromatosis sort one.