An Adult-Onset BRCA2 Finding in a Child’s Exome
A 7-year-old boy with global developmental delay and epilepsy undergoes trio exome sequencing. The report identifies a pathogenic BRCA2 frameshift variant inherited from his 45-year-old father, plus a de novo pathogenic variant in a neurodevelopmental gene that explains his phenotype. The father has no personal history of cancer. The parents are relieved about the explanation but ask whether the BRCA2 result should be disclosed to their son now, whether their 4-year-old daughter should be tested, and whether the father should “do anything.” The mother is not a carrier. The family is from a community with limited access to specialty care.
1. How should the BRCA2 result be communicated and managed within the family?
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The BRCA2 result is a medically actionable secondary finding and should be disclosed to the parents because it has immediate implications for the father. The father should receive confirmation and referral for adult BRCA2-related care: prostate cancer screening beginning around age 40–45, male breast examination, pancreatic cancer surveillance if family history warrants, and melanoma skin examination. The child’s result should be documented, but predictive disclosure to the child should be deferred until he is an adolescent or young adult and can participate in decisions. The parents can be told that the finding does not affect his neurodevelopmental diagnosis or childhood care. The family should receive genetic counseling about the 50% risk to each child and about insurance implications.
2. Should the 4-year-old sister be tested? Why or why not?
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No. The sister should not be tested in childhood for an adult-onset predisposition when there is no childhood intervention. Testing her would remove her future autonomy and could cause insurance or social harms. She can be offered testing in adulthood, typically in her 20s, when BRCA2 surveillance becomes relevant. The parents should understand that each child has a 50% chance of inheriting the father’s BRCA2 variant, but that risk can be addressed later. If the father’s variant is confirmed, the sister’s future testing is straightforward.
3. What ethical and policy issues arise, and how do you address access barriers?
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Key issues include duty to warn versus confidentiality, the child’s future autonomy, secondary findings policy, and insurance discrimination. The father’s result is his own; the child’s result can be shared with parents because it benefits the father and is medically actionable. The family should be told that GINA protects against health insurance discrimination but not life, disability, or long-term care insurance. Access barriers can be addressed through telehealth genetic counseling, referral to a cancer genetics clinic, financial assistance programs, and a written summary for the primary care clinician. The goal is to prevent the finding from being lost while avoiding unnecessary childhood testing.