[Constitutional mismatch repair deficiency syndrome]

Area of Science:

• Oncology
• Genetics
• Pediatrics

Background:

• Constitutional mismatch repair deficiency (CMMR-D) syndrome presents a substantially elevated risk of childhood cancers.
• This rare genetic condition results from inheriting mutations in the same DNA mismatch repair gene from both parents.

Observation:

• A case study details an 8-year-old girl diagnosed with CMMR-D syndrome.
• She developed a brain tumor at age 4, T-cell non-Hodgkin lymphoma at age 6, and presented with multiple hyperpigmented skin lesions.
• The patient tragically died from myelodysplastic syndrome at age 11.

Findings:

• CMMR-D syndrome in pediatric cancer patients can be identified by the presence of multiple primary malignancies.
• Associated skin findings, including hyperpigmentation and hypopigmentation, are key indicators.
• The syndrome highlights a critical link between childhood cancers and inherited genetic predispositions.

Implications:

• Early recognition of CMMR-D syndrome in children with complex cancer histories is crucial for timely intervention.
• Parents of affected children face a heightened risk for Lynch syndrome-associated cancers, such as colorectal and endometrial cancer.
• This underscores the importance of genetic counseling and screening for families with a history of CMMR-D syndrome.