About CMMRD
Understanding the condition, its impact, and why early awareness matters.
What is Constitutional Mismatch Repair Deficiency (CMMRD)?
CMMRD is a hereditary cancer predisposition syndrome caused by mutations in mismatch repair genes. These genes normally help the body identify and repair damaged cells. When they do not function properly, abnormal cells can grow unchecked, leading to cancer.
Children with CMMRD face a significantly higher risk of developing multiple cancers at a young age, particularly brain tumors, gastrointestinal cancers, and blood cancers.
CMMRD at a Glance
Key facts about diagnosis, risk, and disease progression.
What makes CMMRD different from Mismatch Repair Deficiency (MMRD) found in Lynch syndrome?
CMMRD differs from Lynch syndrome in that individuals inherit mutations from both parents, leading to a much higher and earlier cancer risk. While Lynch syndrome increases cancer risk later in life, CMMRD often presents in childhood.
What is the risk for couples who both carry a mutation in their MMR gene to have a child with CMMRD?
If both parents carry a mutation in an MMR gene, there is:
- a 25% chance of having a child with CMMRD
- a 50% chance of having a child with Lynch syndrome
- a 25% chance of having a child with neither
As CMMRD puts children at risk for cancer from infancy, how early are children often diagnosed, and what triggers a diagnosis?
Children with CMMRD can develop cancer at a very young age, sometimes as early as infancy. Many cases are diagnosed between ages 1–10, often after symptoms such as brain tumors or gastrointestinal issues appear.
Aside from elevated cancer risks, are there other health issues someone with CMMRD is at risk for?
In addition to cancer, children with CMMRD often require frequent medical monitoring, including regular scans and procedures. This can impact physical health, emotional well-being, and overall quality of life.
