Cascade Testing: — Getting Your Family Members Tested

Coverage varies by insurer and policy. Cascade testing is less expensive than full sequencing because the laboratory looks at a single defined position in one gene, and many private insurers now include genetic testing under oncology riders. Ayushman Bharat coverage for genetic testing is expanding. Ask your insurer whether predictive genetic testing is included under your current policy before you book, and ask the testing centre for an itemised quote — this is often what insurers require for reimbursement rather than a bundled bill.

If the proband has died, it may be possible to test archived tumour tissue or a previously stored blood sample, depending on what the original laboratory holds. If the proband is alive but unwilling to share their result, you can pursue full genetic sequencing on your own — you do not need another person's cooperation to have your own DNA tested. That route is more expensive and slower, but it does not depend on anyone else. A genetic counsellor can advise which approach fits your situation.

A negative cascade test means you do not carry the specific variant found in your family — and that is genuinely reassuring. It does not clear you of all genetic cancer risk, because you could carry a different variant in a different gene that was never tested, or one not yet characterised. What it removes is the elevated risk associated with the known family variant. You still benefit from routine age-appropriate screening for the general population, and your oncologist can advise whether anything additional is warranted given your broader family history.

For most hereditary cancer syndromes — including BRCA1, BRCA2 and Lynch syndrome — testing children under 18 is generally not recommended. Surveillance for these conditions does not begin until the mid-to-late twenties, so knowing earlier does not change clinical management and adds years of unnecessary anxiety. The exception is a small number of conditions, such as Li-Fraumeni syndrome, where childhood surveillance is indicated. NCCN and the American Society of Human Genetics both advise that predictive testing in minors should be deferred unless a child's clinical management would change as a direct result.

When the exact family variant is known and confirmed as pathogenic, cascade testing for that specific variant is highly accurate — the laboratory is checking a single defined position in the genome. The main source of uncertainty is not the test itself but the status of the original variant. If the proband's report classified the variant as a VUS rather than pathogenic, cascade testing is generally not offered until that classification changes. Confirm whether the family variant has been reported as pathogenic before arranging testing.

Yes. CION centres arrange genetics referrals and coordinate cascade testing with partner laboratories. Bring a copy of your relative's genetic report to your first appointment — it significantly shortens the process. If you do not yet have it, come anyway; the team will help you locate the relevant information. Cascade testing is done as an outpatient. A genetic counsellor is involved in going through your result with you in person before you leave.