Atypical 22q11.2 Finding on Cell-Free DNA at 13 Weeks
A 34-year-old G2P1 at 12 weeks 6 days undergoes cell-free DNA screening because of maternal age. The report states low risk for trisomies 21, 18, and 13 but flags an atypical finding suggestive of a 22q11.2 deletion; fetal fraction is 8%. A follow-up ultrasound at 13 weeks is normal. The patient says she has already scheduled a termination at 15 weeks because 'the deletion causes severe heart defects and intellectual disability,' and she does not want 'more tests that delay things.' She and her partner have a 3-year-old unaffected son. The counselor has 30 minutes and must address the couple's request for a termination referral while explaining the limits of screening and the range of outcomes. The patient is privately insured; CVS is available at 14 weeks and microarray results would take 7–10 days.
1. What is the appropriate response to the patient's request for a termination referral?
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Separate screening from diagnosis before acting on the request. Cell-free DNA is a screening test; an atypical 22q11.2 finding has a lower positive predictive value than common aneuploidy screening because the deletion is rare, fetal fraction and deletion size affect detection, and some flagged results are false positives or reflect confined placental mosaicism. A normal 13-week ultrasound does not exclude the deletion, and the phenotype is highly variable. Offer chorionic villus sampling with chromosomal microarray rather than karyotype, because a standard karyotype cannot detect a microdeletion. A 7–10 day result can still inform her decision where termination is legal. Do not withhold a termination referral as a condition of testing, but the referral should follow informed consent: she needs to understand that the screen is not a diagnosis and that outcomes range from significant cardiac and developmental problems to much milder courses. Document the discussion. If she declines testing, document informed refusal and arrange postnatal genetics and cardiology follow-up.
2. How should the counselor discuss phenotype and uncertainty without coercing the patient?
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Use a non-directive framework and ask what outcomes matter to her. Explain that 22q11.2 deletion syndrome can include congenital heart disease, palatal abnormalities, hypocalcemia, immune differences, developmental delay, and later psychiatric risk, but no prenatal test predicts severity. Avoid saying 'mild' or 'severe' as a fixed category; describe ranges and note that many affected adults live independently while others need substantial support. Distinguish the screening result from a confirmed fetal diagnosis and state what microarray would and would not tell her. Acknowledge that waiting 7–10 days feels unacceptable and explore why: fear of a late termination, prior loss, or pressure from her partner. Offer a joint meeting with maternal-fetal medicine and genetics, written materials, and a follow-up call. Make clear that either choice-diagnostic testing or proceeding without it-will receive continued care. The goal is informed deliberation, not persuasion toward a particular reproductive decision.
3. The patient declines CVS and says she will terminate at 15 weeks. What should the counselor do next?
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Respect the decision and avoid abandoning her. Confirm she understands that the termination will proceed without a confirmed fetal diagnosis and that the cfDNA result may be a false positive. Ask whether she wants a postnatal or products-of-conception microarray if the termination occurs; this can provide information for future pregnancies and for the couple's own health, but it is optional and should not be a condition of care. Provide the referral through the usual pathway and document capacity, informed refusal of diagnostic testing, and the counseling content. Offer a follow-up appointment to discuss recurrence risk and future prenatal options, including early ultrasound and diagnostic testing in a subsequent pregnancy. Notify the appropriate obstetric team so handoffs are coordinated. If she later changes her mind before the procedure, make clear that CVS or amnio can still be arranged quickly. The counselor's role is to protect informed choice, not to gatekeep the referral.