Touchpoint 7: Implications for family members

When it comes to genomic testing, it’s important for both the patient and the clinician to consider any impact the results may have on the patient’s family members. Across these next two steps, we’ll look at different examples to illustrate why cases can be so complex.

Implications of genomic testing for close relatives

Where one or more pathogenic variant(s) are identified in a patient, cascade genetic testing may be made available to their family members.

For example, if a diagnostic test in an individual with a cardiomyopathy identifies a causative pathogenic variant, that result could be used to offer the patient’s close, unaffected relatives a pre-symptomatic (sometimes called predictive) test to investigate whether they have the same pathogenic variant, which may be associated with an increased risk of developing cardiomyopathy.

This would enable clinicians to offer targeted screening and management only to relatives who are at risk, and to avoid screening individuals who are not. Note that cascade testing for family members would only be available for a variant that was classified as pathogenic (or likely pathogenic).

In the case of a variant of uncertain significance being identified, no cascade screening could be offered and, with no way of establishing which of them were at risk, all family members would continue to require clinical screening for cardiomyopathy.

Scenario: The Raynor family

_{Figure 1: The Raynor family pedigree
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Michael Raynor, a 49-year-old male, presented to his GP with ongoing shortness of breath, chest pains and episodes of light-headedness. Subsequent investigations and referral to the Inherited Cardiac Conditions service led to a clinical diagnosis of hypertrophic cardiomyopathy (HCM). He was offered a genetic test, and a pathogenic variant in the MYBPC3 gene was identified. This confirms the clinical diagnosis and enables testing in his immediate family.

Michael has three children: Sarah (25), James (23) and Findlay (15). Sarah is a runner and is training for the London Marathon, and she is now worried about whether she should be training as hard as she is. James wants to start a family with his partner soon; they are extremely worried about passing this variant on to their potential future children, but James has heard that there are certain reproductive options they could consider if he has a genetic test. Findlay plays rugby and wants to become a professional rugby player when he leaves school, but he is worried that he will not be able to play or will not be signed by a team if he finds out he has the familial variant.

The role of genetic counselling

Family dynamics and communication

_{Figure 2: Implications of genomic testing for family members
© Health Education England}
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The wider Raynor family

Michael has two brothers, Joseph and Scott. Joseph wishes to be tested and is seeking a referral. Scott does not want to be tested himself, but he has adult children who do. Testing Scott’s children may reveal information about Scott, for which he has not given his consent; however, his children are still concerned about their own health.

Michael’s mother died following a heart attack and had a family history of heart problems, but he has no contact with his maternal relatives and no tissue or genetic material was stored prior to his mother’s death. His father Matthew does not want to be tested because he does not wish to know the results: he would feel guilty if he found out that he had passed the variant on himself, but at the same time he does not wish to have any blame placed on his late wife. He is asymptomatic but could still develop HCM if he carries the pathogenic variant. Michael is worried about his father.

Because there are no samples to test, we cannot determine whether the variant found in Michael came from his mother or his father. This means that, ultimately, we do not know which of his relatives may also be at risk of developing HCM.

Considering Scott and Matthew

The case of Michael’s brother Scott illustrates how different wishes within a family must be balanced and carefully considered. Clearly, Scott cannot and should not be coerced into having a genetic test. However, if either of his children – who do wish to be tested – were found to have the pathogenic variant, this would indirectly confirm that Scott has it too, and that he therefore has an increased risk of developing HCM. In this situation, genetic counselling will be crucial in helping to find a solution that is acceptable to Scott and his children.

We must also consider Michael’s father, Matthew. Although most people accept that they did not choose to pass on a genetic condition to their children, many experience feelings of guilt or shame. It can often be difficult for the patient to break the bad news and, when they do, they themselves may end up supporting their relatives, who may be anxious or confused by the new information. A combination of these factors may lead to avoidance on the part of the patient: they may be reluctant to tell their relatives at all, which could have an impact on their relatives’ health or life choices.

In the next step, we’ll look at some more challenging examples with more complex ethical considerations.