Genetic counselling and recurrence risk

Synopsis

Deliver non-directive genomic counselling, calculate and communicate recurrence risk from diagnosis and inheritance, explain uncertainty and reproductive options, support family communication and document an agreed plan across life stages.

• Begin with the person's question, values, language, family structure and current understanding; genetic counselling is a communication and decision process rather than a laboratory result recital.
• Confirm the exact diagnosis, gene or chromosome finding, inheritance, penetrance, variant classification and whether parental or segregation testing is complete before quoting recurrence figures.
• Separate chance of inheriting a variant from chance of developing disease and expected severity; penetrance, sex, mosaicism and variable expression can make these different.
• Mendelian probabilities apply independently to each conception: previous outcomes do not make the next pregnancy due for an affected or unaffected result.
• A negative parental blood test after an apparently de novo diagnosis usually lowers recurrence substantially but cannot remove germline mosaicism or an unexpected biological relationship from consideration.
• Present pregnancy without testing, prenatal diagnosis, preimplantation genetic testing where eligible, donor conception, adoption and choosing not to have children as options without ranking moral worth.
• Discuss who in the wider family may benefit and support patient-led communication with a genetics letter; do not assume permission to contact relatives directly.
• Record the numerical estimate, its assumptions, residual uncertainty, choices discussed, emotional response and who will arrange each test or referral.