Tailored approach to inform family members at risk of inherited cardiac diseases: a RCT

Rationale: Predictive genetic testing for family members at risk of inherited cardiac diseases has become part of genetic clinical practice. In the Netherlands, family members at risk of inheriting the mutation are generally informed by the index patient, supported by a family letter of the genetic counsellor. Previous research shows that with this approach on average only half of family members at risk of inherited cardiac diseases attend genetic counselling. To prevent fatal consequences of these diseases, uptake should be optimal.

Objectives: Therefore, this study aims to investigate uptake of genetic counselling and testing using a tailored approach towards informing family members at risk, in which index patients may decide which family members they will inform themselves at first and which family members they prefer to be informed by the genetic counsellor directly, compared to uptake using the usual approach. Secondary aims are to evaluate acceptance of the used approach and impact on family relationships and psychological functioning.

Methods: This study is a multicenter randomized clinical trial. Adult index patients with an inherited cardiac disease and a pathogenic mutation are eligible to participate. In addition, first-degree (or second-degree in case of a deceased connecting first-degree family member affected or suspected to be affected) family members at risk of inheriting the mutation of enrolled index patients will be invited to participate as well. Uptake of genetic counselling and testing of family members in the first year after detection of the pathogenic mutation in the index patient will be compared to the total number of at-risk family members. Participants will be asked to complete questionnaires on appreciation of the used approach, perceived impact on family relationships and impact on psychological functioning (i.e., worrying and feelings of fear and depression).

In the Netherlands, family members at risk of inherited cardiac disease are generally informed by the index patient (i.e., the first in the family diagnosed with an inherited cardiac disease) about the advice of cardiac monitoring and predictive genetic testing, supported by a family letter written by the genetic counsellor. However, previous research shows that the uptake of genetic counselling and testing is relatively low. Ideally, this percentage should be higher to prevent fatal consequences of the disease. This study aims to investigate a tailored approach towards informing at risk compared to usual care (i.e., by the index patient). We hypothesize that uptake of genetic counselling and testing with a tailored approach will be improved.

Index patients:

T1: One month after receiving genetic test result

T2: Nine months after receiving genetic test result

Family members:

T1: Directly after attending genetic counselling/genetic testing

In this study, a tailored approach of informing family members at risk of inherited cardiac diseases will be investigated, in which index patients will be informed about the risk for their family members and will be offered the choice which family members will be informed by the index patients themselves at first and which family members they prefer to be directly informed by the genetic counsellor. In both cases, a family letter with information written by the genetic counsellor is provided. After one month, family members informed by the index patients will receive an additional letter of the genetic counsellor with consent of the index patient. In addition, a website-link with disease specific information will be provided for both index patients and family members. In the control group, the standard approach will be used, in which the index patient is asked to inform their family members, supported by a family letter written by the genetic counsellor.