Medical and ethical challenges in low penetrance copy number variants management: state-of-the-art in the Portuguese Clinical Genetics community

Low-Penetrance Copy Number Variants (LP-CNVs) are well-known to contribute to neurodevelopmental disorders and are also found in healthy individuals, presenting significant challenges to genetic counselling. However, data on the clinical management of LP-CNVs in Portugal is lacking. To address this gap, an online questionnaire was administered to Clinical Geneticists in Portugal regarding their management of LP-CNV. The results showed a significant absence of agreement on LP-CNVs disclosure, particularly concerning whether decisions should be guided by expert panels or individualised for each case. Clinicians acknowledged the substantial challenges patients and families face in understanding genetic information, highlighting the need for a shared decision-making approach. Furthermore, there was considerable variability in ethical perspectives regarding prenatal diagnosis and preimplantation genetic testing for LP-CNVs, emphasising the need for clear guidelines. Our results strongly advocate for the development of national guidelines mirroring those established in other countries. This work underscores several complex ethical issues that require further exploration both in Portugal and internationally, including: equitable access to knowledge and economic fairness; balancing child/embryo welfare against parental autonomy and right to knowledge of parents/couples; the potential for genetic discrimination and stigma; the definitions of a "good"/"healthy" life and the authority to make such determination; and the imperative for enhanced training and education for Geneticists to facilitate effective communication and informed consent.