Genetic testing preferences in families containing multiple individuals with epilepsy

Genetic testing and counseling for the unexplained epilepsies: An evidence‐based practice guideline of the National Society of Genetic Counselors

Epilepsy, defined by the occurrence of two or more unprovoked seizures or one unprovoked seizure with a propensity for others, affects 0.64% of the population and can lead to significant morbidity and mortality. A majority of unexplained epilepsy (seizures not attributed to an acquired etiology, such as trauma or infection) is estimated to have an underlying genetic etiology. Despite rapid progress in understanding of the genetic underpinnings of the epilepsies, there are no recent evidence-based guidelines for genetic testing and counseling for this population. This practice guideline provides evidence-based recommendations for approaching genetic testing in the epilepsies using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) Evidence to Decision framework. We used evidence from a recent systematic evidence review and meta-analysis of diagnostic yield of genetic tests in patients with epilepsy. We also compiled data from other sources, including recently submitted conference abstracts and peer-reviewed journal articles. We identified and prioritized outcomes of genetic testing as critical, important or not important and based our recommendations on outcomes deemed critical and important. We considered the desirable and undesirable effects, value and acceptability to relevant stakeholders, impact on health equity, cost-effectiveness, certainty of evidence, and feasibility of the interventions in individuals with epilepsy. Taken together, we generated two clinical recommendations: (1) Genetic testing is strongly recommended for all individuals with unexplained epilepsy, without limitation of age, with exome/genome sequencing and/or a multi-gene panel (>25 genes) as first-tier testing followed by chromosomal microarray, with exome/genome sequencing conditionally recommended over multi-gene panel. (2) It is strongly recommended that genetic tests be selected, ordered, and interpreted by a qualified healthcare provider in the setting of appropriate pre-test and post-test genetic counseling. Incorporation of genetic counselors into neurology practices and/or referral to genetics specialists are both useful models for supporting providers without genetics expertise to implement these recommendations.

Changes in empowerment and anxiety of patients and parents during genetic counselling for epilepsy

Genetic testing and counselling are increasingly important in epilepsy care, aiming at finding a diagnosis, understanding aetiology and improving treatment and outcome. The psychological impact of genetic counselling from patients' or parents' perspectives is, however, unknown. We studied the counselee-reported outcome of genetic counselling before and after genetic testing for epilepsy by evaluating empowerment - a key outcome goal of counselling reflecting cognitive, decisional and behavioural control, emotional regulation and hope - and anxiety. We asked patients or their parents (for those <16 years or intellectually disabled) referred for genetic testing for epilepsy in two university hospitals between June 2014 and 2017 to complete the same two questionnaires at three timepoints: before and after pre-test counselling and after post-test counselling. Empowerment was measured with the Genetic Counselling Outcome Scale (GCOS-18); anxiety with the short State Trait Anxiety Inventory (STAI-6). A total of 63 participants (55 parents with the age of 29-66 years; 8 patients with the age of 21-42 years) were included in our study. Empowerment significantly increased during the genetic counselling trajectory with a medium effect size (p < 0.001, d = 0.57). A small but significant increase in empowerment was already seen after pre-test counselling (p = 0.038, d = 0.29). Anxiety did not change significantly during the counselling trajectory (p = 0.223, d = -0.24). Our study highlights that patients with epilepsy or their parents show a clinically relevant increase in empowerment after genetic counselling. Empowerment was already increased after pre-test counselling, suggesting the importance of counselling before initiating genetic testing for epilepsy. However, individual differences in changes in empowerment and anxiety were seen, suggesting that counselling could be further improved, based on individual needs.

Genetic attribution and perceived impact of epilepsy in multiplex epilepsy families

OBJECTIVE

Studies have found that affected individuals who believe the cause of their disorder is genetic may react in various ways, including optimism for improved treatments and pessimism due to perceived permanence of the condition. This study assessed the psychosocial impact of genetic attribution among people with epilepsy.

METHODS

Study participants were 165 persons with epilepsy from multiplex epilepsy families who completed a self-administered survey. Psychosocial impact of epilepsy was assessed with the Impact of Epilepsy Scale, containing items about relationships, employment, overall health, self-esteem, and standard of living. Genetic attribution was assessed using a scale derived from three items asking about the role of genetics in causing epilepsy in the family, the chance of having an epilepsy-related mutation, and the influence of genetics in causing the participant's epilepsy. We estimated prevalence ratios (PRs) for impact of epilepsy above the median using Poisson regression with robust standard errors, adjusting for number of lifetime seizures and time since last seizure.

RESULTS

Participants' age averaged 51 years; 87% were non-Hispanic white, 63% were women, and 54% were college graduates. The genetic attribution scale was significantly associated with having a high impact of epilepsy (adjusted PR = 1.4, 95% confidence interval = 1.07-1.91, P = .02). One of the three genetic attribution questions was also significantly associated with a high impact of epilepsy (belief that genetics had a big role in causing epilepsy in the family, adjusted PR = 1.8).

SIGNIFICANCE

These findings reflect an association between the psychosocial impact of epilepsy and the belief that epilepsy has a genetic cause, among people with epilepsy in families containing multiple affected individuals. This association could arise either because belief in a genetic cause leads to increased psychosocial impacts, or because a greater psychosocial impact of epilepsy leads some to believe their epilepsy is genetic.

Return of individual results in epilepsy genomic research: A view from the field

Genomic findings are emerging rapidly in 2 large, closely related epilepsy research consortia: the Epilepsy Phenome/Genome Project and Epi4K. Disclosure of individual results to participants in genomic research is increasingly viewed as an ethical obligation, but strategies for return of results were not included in the design of these consortia, raising complexities in establishing criteria for which results to offer, determining participant preferences, managing the large number of sites involved, and covering associated costs. Here, we describe the challenges faced, alternative approaches considered, and progress to date. Experience from these 2 consortia illustrates the importance, for genomic research in epilepsy and other disorders, of including a specific plan for return of results in the study design, with financial support for obtaining clinical confirmation and providing ongoing support for participants. Participant preferences for return of results should be established at the time of enrollment, and methods for allowing future contacts with participants should be included. In addition, methods should be developed for summarizing meaningful, comprehensible information about findings in the aggregate that participants can access in an ongoing way.

Genetic Testing Preferences of Individuals in Families with Essential Tremor

Background

The search for essential tremor (ET) genes is active, and it is only a matter of time before genetic tests become available. Genetic testing preferences in families have been studied in numerous other neurological disorders but there are no published data about ET.

Methods

We surveyed 34 ET probands and their relatives (43 affected, 28 unaffected) enrolled in our Family Study of Essential Tremor to assess their interest in genetic testing. We examined whether clinical factors influenced their interest in testing. Clinical utility (“Your physician will be able to use the information obtained to improve your care”) and penetrance (“How likely an individual who carries an ET gene is to develop ET”) were defined for participants.

Results

Interest in genetic testing was high in ET families (90/105 [85.7%]). There was a significant difference between affected (including probands and affected relatives) and unaffected relatives in terms of their interest in genetic testing, with the former being more interested (70/77 [90.9%] vs. 20/28 [71.4%] p = 0.04). Participants were more likely to want testing in the scenarios with high clinical utility; disease penetrance was not a determining factor (all p < 0.05). Sixteen hypothetical factors were identified that might influence a participant’s decision to undergo genetic testing for ET.

Discussion

Interest in genetic testing was high in ET families. While genetic testing is not currently available for ET, the hunt for ET genes is ongoing, and this is a highly familial disorder. Understanding genetic testing preferences will greatly aid clinicians once a genetic test becomes available.

Mood disorders in familial epilepsy: A test of shared etiology

OBJECTIVE

Mood disorders are the most common comorbid conditions in epilepsy, but the cause remains unclear. One possible explanation is a shared genetic susceptibility to epilepsy and mood disorders. We tested this hypothesis by evaluating lifetime prevalence of mood disorders in relatives with and without epilepsy in families containing multiple individuals with epilepsy, and comparing the findings with rates from a general population sample.

METHODS

The Composite International Diagnostic Interview was administered to 192 individuals from 60 families, including 110 participants with epilepsy of unknown cause (50 focal epilepsy [FE], 42 generalized epilepsy [GE], 6 FE and GE, 12 unclassifiable) and 82 relatives without epilepsy (RWOE). Odds ratios (ORs) for lifetime prevalence of mood disorders in participants with versus without epilepsy were computed through logistic regression, using generalized estimation equations to account for familial clustering. Standardized prevalence ratios (SPRs) were used to compare prevalence in family members with general population rates.

RESULTS

Compared with RWOE, ORs for mood disorders were significantly increased in participants with FE (OR = 2.4, 95% confidence interval [CI] = 1.1-5.2) but not in those with GE (OR = 1.0, 95% CI = 0.4-2.2). In addition, prevalence of mood disorders was increased in individuals with epilepsy who had ≥1 relative with FE. Compared with general population rates, mood disorders were significantly increased in individuals with FE but not in those with GE. Rates were also increased in RWOE, but not significantly so (SPR = 1.4, P = .14).

SIGNIFICANCE

These findings are consistent with the hypothesis of shared genetic susceptibility to epilepsy and mood disorders, but suggest (1) the effect may be restricted to FE, and (2) the shared genetic effect on risk of mood disorders and epilepsy may be restricted to individuals with epilepsy, that is, to those in whom the genetic risk for epilepsy is "penetrant."

[Epilepsy-new diagnostic tools, old drugs? : Therapeutic consequences of epilepsy genetics]

BACKGROUND

Recent advances in the field of epilepsy genetics have led to an increased fraction of patients with epilepsies where the etiology of the disease could be identified. Nevertheless, there is some criticism regarding the use of epilepsy genetics because in many cases the identification of a pathogenetic mutation does not lead to an adaptation of therapy or to an improved prognosis. In addition, the interpretation of genetic results might be complicated due to the considerable numbers of variants of unclear significance.

OBJECTIVE

This publication presents the arguments in favour of a broad use of genetic investigations for children with epilepsies. Several diseases where a genetic diagnosis does in fact have direct therapeutic consequences are mentioned. In addition, the indirect impact of an established etiology, encompassing the avoidance of unnecessary diagnostic measures, possibility of genetic counselling, and the easing of the psychologic burden for the caregivers, should not be underestimated.

CONCLUSION

The arguments in favour of broad genetic diagnostics prevail notwithstanding the lack of relevant new developments regarding the therapy.

Depression and genetic causal attribution of epilepsy in multiplex epilepsy families

OBJECTIVES

Rapid advances in genetic research and increased use of genetic testing have increased the emphasis on genetic causes of epilepsy in patient encounters. Research in other disorders suggests that genetic causal attributions can influence patients' psychological responses and coping strategies, but little is known about how epilepsy patients and their relatives will respond to genetic attributions of epilepsy. We investigated the possibility that among members of families containing multiple individuals with epilepsy, depression, the most frequent psychiatric comorbidity in the epilepsies, might be related to the perception that epilepsy has a genetic cause.

METHODS

A self-administered survey was completed by 417 individuals in 104 families averaging 4 individuals with epilepsy per family. Current depression was measured with the Patient Health Questionnaire. Genetic causal attribution was assessed by three questions addressing the following: perceived likelihood of having an epilepsy-related mutation, perceived role of genetics in causing epilepsy in the family, and (in individuals with epilepsy) perceived influence of genetics in causing the individual's epilepsy. Relatives without epilepsy were asked about their perceived chance of developing epilepsy in the future, compared with the average person.

RESULTS

Prevalence of current depression was 14.8% in 182 individuals with epilepsy, 6.5% in 184 biologic relatives without epilepsy, and 3.9% in 51 individuals married into the families. Among individuals with epilepsy, depression was unrelated to genetic attribution. Among biologic relatives without epilepsy, however, prevalence of depression increased with increasing perceived chance of having an epilepsy-related mutation (p = 0.02). This association was not mediated by perceived future epilepsy risk among relatives without epilepsy.

SIGNIFICANCE

Depression is associated with perceived likelihood of carrying an epilepsy-related mutation among individuals without epilepsy in families containing multiple affected individuals. This association should be considered when addressing mental health issues in such families.

Parents' interest in genetic testing of their offspring in multiplex epilepsy families

OBJECTIVE

To evaluate parents' interest in genetic testing of their offspring in families containing multiple individuals with epilepsy.

METHODS

Seventy-seven parents with affected offspring and 173 parents without affected offspring from families containing multiple individuals with epilepsy completed a questionnaire asking about their interest in genetic testing of their offspring. Interest in testing was ascertained in four scenarios defined by clinical utility and penetrance of the gene in the test (100% vs. 50%). Pairwise agreement in interest was assessed between parents for testing themselves versus their offspring, and between mothers and fathers for their offspring.

RESULTS

Among parents with affected offspring, the proportion interested in genetic testing of offspring ("diagnostic testing") was 86% in the 100% penetrance, clinical utility scenario, and 71% in the 100% penetrance, no clinical utility scenario (p = 0.007). Among parents without affected offspring, comparable proportions interested in genetic testing of offspring ("predictive testing") were 74% and 53% (p < 0.001), and were significantly lower than in parents with affected offspring (clinical utility, p = 0.02; no clinical utility, p = 0.01). Interest in testing did not differ by gene penetrance. Parents' agreement in testing interest for themselves versus their offspring was "substantial" (90% agreement, κ = 0.72) for a test with clinical utility, and "almost perfect" for a test without clinical utility (94% agreement, κ = 0.88). Agreement in testing interest between mothers and fathers was "moderate" for a test with clinical utility (85% agreement, κ = 0.48,), and "fair" for a test without clinical utility (67% agreement, κ = 0.30).

SIGNIFICANCE

Interest in diagnostic genetic testing is strong among parents with offspring with epilepsy, particularly when the test offers clinical utility. Testing interest is lower for a diagnostic test without clinical utility, or for a predictive test in offspring at risk of developing epilepsy in the future.

Genetic causal attribution of epilepsy and its implications for felt stigma

OBJECTIVE

Research in other disorders suggests that genetic causal attribution of epilepsy might be associated with increased stigma. We investigated this hypothesis in a unique sample of families containing multiple individuals with epilepsy.

METHODS

One hundred eighty-one people with epilepsy and 178 biologic relatives without epilepsy completed a self-administered survey. In people with epilepsy, felt stigma was assessed through the Epilepsy Stigma Scale (ESS), scored 1-7, with higher scores indicating more stigma and >4 indicating some felt stigma. Felt stigma related to having epilepsy in the family was assessed through the Family Epilepsy Stigma Scale (FESS), created by replacing "epilepsy" with "epilepsy in my family" in each ESS item. Genetic attribution was assessed through participants' perceptions of the (1) role of genetics in causing epilepsy in the family, (2) chance they had an epilepsy-related mutation, and (3) (in people with epilepsy) influence of genetics in causing their epilepsy.

RESULTS

Among people with epilepsy, 22% met criteria for felt stigma (ESS score >4). Scores were increased among individuals who were aged ≥60 years, were unemployed, reported epilepsy-related discrimination, or had seizures within the last year or >100 seizures in their lifetime. Adjusting for other variables, ESS scores in people with epilepsy were significantly higher among those who perceived genetics played a "medium" or "big" role in causing epilepsy in the family than in others (3.4 vs. 2.7, p = 0.025). Only 4% of relatives without epilepsy had felt stigma. Scores in relatives were unrelated to genetic attribution.

SIGNIFICANCE

In these unusual families, predictors of felt stigma in individuals with epilepsy are similar to those in other studies, and stigma levels are low in relatives without epilepsy. Felt stigma may be increased in people with epilepsy who believe epilepsy in the family has a genetic cause, emphasizing the need for sensitive communication about genetics.

Genetics of Epilepsy in Clinical Practice

Genetics should now be part of everyday clinical epilepsy practice. Good data exist to provide empiric risks based on epilepsy syndrome diagnosis. Investigation of the molecular basis of some epilepsies is now a practical clinical task and is of clear value to the patient and family. In some cases, specific therapeutic decisions can now be made based on genetic findings, and this scenario of precision therapy is likely to increase in the coming years.

"It's good to know": experiences of gene identification and result disclosure in familial epilepsies

Recognition of the role of genetics in the epilepsies has increased dramatically, impacting on clinical practice across many epilepsy syndromes. There is limited research investigating the impact of gene identification on individuals and families with epilepsy. While research has focused on the impact of delivering genetic information to families at the time of diagnosis in genetic diseases more broadly, little is known about how genetic results in epileptic diseases influences people's lives many years after it has been conveyed. This study used qualitative methods to explore the experience of receiving a genetic result in people with familial epilepsy. Interviews were conducted with individuals with familial epilepsies in whom the underlying genetic mutation had been identified. Recorded interviews underwent thematic analysis. 20 individuals from three families with different epilepsy syndromes and causative genes were interviewed. Multiple generations within families were studied. The mean time from receiving the genetic result prior to interview was 10.9 years (range 5-14 years). Three major themes were identified: 1) living with epilepsy: an individual's experience of the severity of epilepsy in their family influenced their view. 2) Clinical utility of the test: participants expressed varying reactions to receiving a genetic result. While for some it provided helpful information and relief, others were not surprised by the finding given the familial context. Some valued the use of genetic information for reproductive decision-making, particularly in the setting of severely affected family members. While altruistic reasons for participating in genetic research were discussed, participants emphasised the benefit of participation to them and their families. 3) 'Talking about the family genes': individuals reported poor communication between family members about their epilepsy and its genetic implications. The results provide important insights into the family experience of genetic epilepsies and communication within families. This information can be used to inform the development of guidelines for genetic result disclosure and genetic counselling for individuals and families with epilepsies.