By Zöe Powis, MS, CGC

Better Health

With the advent of exome and genome testing, laboratories began to identify changes in genes (variants) unrelated to the primary reason for genetic testing. These findings became known as “secondary findings.” There has been debate among providers since the American College of Medical Genetics and Genomics (ACMG) published and then revised their recommendations for a minimum list of genes where secondary findings should be reported.  Included are genes that may identify a predisposition to hereditary cancers, cardiac conditions, and malignant hyperthermia, a condition associated with complications with the use of certain types of anesthesia.

Ethical concerns surrounding secondary findings include presymptomatic testing of minors, potential insurance discrimination, and the possibility of emotional harm. The European Society of Human Genetics (ESHG) issued recommendations suggesting the use of gene panels to avoid the possible identification of secondary findings, and the Canadian College of Medical Geneticists (CCMG) recommended providers utilize a thoughtful approach to ordering testing with secondary findings.

Results from secondary findings can provide many benefits to patients and families. Studies have shown that in unselected populations, 1% to 2% of people are found to have pathogenic variants in genes for which they may have no family history. A discovery of a pathogenic variant, for example in RYR1 or CACNA1S, can lead to life-saving measures for individuals and with malignant hyperthermia. A mother of a child with intellectual disability may not follow general cancer breast screening guidelines as she is stressed with her child’s healthcare and therapies. Finding out her son has a BRCA1 pathogenic variant can lead to her testing and/or following guidelines that can reduce her risk of cancer and potentially even save her life.  It can also help her son when he gets older pursue increased surveillance.

In contrast, the information secondary findings can provide may not be wanted by the family or the patient. Parents may not want for their infant daughter to know she has a BRCA pathogenic mutation or know that their young son has a susceptibility to colon cancer later in life. A parent of a child in the NICU may not have the emotional capability at that time to process additional results in addition to dealing with a critically ill infant. In these situations, patients, families, and providers may decide to opt out of receiving secondary findings with exome testing. For secondary findings with the Quest Exome with CNV, providers must consent and explain potential benefits, results, and limitations to their patients in order to have secondary findings performed (http://www.questexome.com/).

Increasingly, providers are seeking out genetic testing options that help them to diagnose and care for patients without having to address secondary findings.  NewbornDx, a test of over 1,700 genes tailored to conditions in the NICU, has been specifically developed with the concerns like identification of secondary findings in newborns in mind. It can provide a written result in 3-7 days, at a lower cost than some alternative testing options that may identify secondary findings. (https://www.athenadiagnostics.com/newborndx). This test circumvents the psychological and logistical issues with informed consent for secondary findings in the NICU.

Consideration of genetic testing with secondary findings has many ethical, medical, and psychological implications for patients and their families. To talk to a genetic counselor to learn more about secondary findings and how they may impact testing and your patients, please contact Quest Genomics Client Services at 1.866.GENE.INFO (1.866.436.3463).

References:
Green RC, Berg JS, et al.; American College of Medical Genetics and Genomics. ACMG recommendations for reporting of incidental findings in clinical exome and genome sequencing. Genet Med 2013;15:565–574.

Kali, S, Adelman K, et al. Recommendations for reporting of secondary findings in clinical exome and genome sequencing, 2016 update (ACMG SF v2.0): a policy statement of the American College of Medical Genetics and Genomics. Genet Med 2017;19:249–255. https://doi.org/10.1038/gim.2016.190

van El CG, Cornel MC, et al. Whole-genome sequencing in health care: recommendations of the European society of human genetics. Eur J Hum Genet 2013;21:580-584.

Matthijs G, Souche E, et al. Guidelines for diagnostic next-generation sequencing Eur J Hum Genet  2016;24:2-5.

Boycott K, Hartley T, et al. The clinical application of genome-wide sequencing for monogenic diseases in Canada: position Statement of the Canadian College of Medical Geneticists. J Med Genet 2015;52:431-437.

Saelaert M, Mertes H, et al. Ethical values supporting the disclosure of incidental and secondary findings in clinical genomic testing: a qualitative study. BMC Med Ethics 2020;21(9). https://doi.org/10.1186/s12910-020-0452-0

Sapp JC, Johnston JJ, et al. Evaluation of recipients of positive and negative secondary findings evaluations in a hybrid CLIA‐research sequencing pilot. Am Journal Hum Genet 2018;103(3):358–366. https://doi.org/10.1016/j.ajhg.2018.07.018