Table 1

Overview of the potential benefits and harms of CMMRD counselling and testing in a child suspected to have sporadic NF1/Legius syndrome without malignancy and negative outcome of NF1/SPRED1 germline mutation analysis

Potential benefitsPotential harms

  • Opportunity to begin surveillance before cancer development.

  • Parents can be informed of the recurrence risk in a sibling/future child.

  • Lynch syndrome can be diagnosed in family members and surveillance initiated.

  • Risks associated with intensive surveillance while efficacy has not yet been evaluated in a large cohort and attenuated forms of CMMRD exist.

  • Risk of identifying a VUS, resulting in management dilemmas and potentially inducing anxiety.

  • Risk of diagnosing Lynch syndrome in a minor.

  • CMMRD, constitutional mismatch repair deficiency; VUS, variant of unknown significance.