Outcomes of genetic test disclosure and genetic counseling in a large Parkinson's disease research study

Ethical Considerations for Identifying Individuals in the Prodromal/Early Phase of Parkinson's Disease: A Narrative Review

The ability to identify individuals in the prodromal phase of Parkinson's disease has improved in recent years, raising the question of whether and how those affected should be informed about the risk of future disease. Several studies investigated prognostic counselling for individuals with isolated REM sleep behavior disorder and have shown that most patients want to receive information about prognosis, but autonomy and individual preferences must be respected. However, there are still many unanswered questions about risk disclosure or early diagnosis of PD, including the impact on personal circumstances, cultural preferences and specific challenges associated with different profiles of prodromal symptoms, genetic testing or biomarker assessments. This narrative review aims to summarize the current literature on prognostic counselling and risk disclosure in PD, as well as highlight future perspectives that may emerge with the development of new biomarkers and their anticipated impact on the definition of PD.

Systematic review of the uptake and outcomes from returning secondary findings to adult participants in research genomic testing

The increasing use of genomic sequencing in research means secondary findings (SF) is more frequently detected and becoming a more pressing issue for researchers. This is reflected by the recent publication of multiple guidelines on this issue, calling for researchers to have a plan for managing SF prior to commencing their research. A deeper understanding of participants' experiences and outcomes from receiving SF is needed to ensure that the return of SF is conducted ethically and with adequate support. This review focuses on the uptake and outcomes of receiving actionable SF for research participants. This review included studies from January 2010 to January 2023. Databases searched included Medline, Embase, PsycINFO, and Scopus. Of the 3903 studies identified, 29 were included in the analysis. The uptake of SF ranged between 20% and 97%, and outcomes were categorized into psychological, clinical, lifestyle and behavioral, and family outcomes. The results indicate there is minimal psychological impact from receiving SF. Almost all participants greatly valued receiving SF. These findings highlight considerations for researchers when returning results, including the importance of involving genetic health professionals in consenting, results return process, and ensuring continuity of care by engaging healthcare providers.

Providing genetic testing and genetic counseling for Parkinson's disease to the community

PURPOSE

To evaluate the feasibility and impact of offering genetic testing and counseling to patients with Parkinson's disease (PD), with the potential to enroll in gene-targeted clinical trials and improve clinical care.

METHODS

A multicenter, exploratory pilot study at 7 academic hospital sites in the United States tracked enrollment and randomized participants to receive results and genetic counseling at local sites or by genetic counselors, remotely. Follow-up surveys measured participant/provider satisfaction, knowledge, and psychological impact.

RESULTS

From September 5, 2019 to January 4, 2021, 620 participants were enrolled and 387 completed outcome surveys. There were no significant differences in outcomes between local and remote sites, with both arms reporting high knowledge and satisfaction scores (>80%). Notably, 16% of those tested had reportable PD gene variants (pathogenic/likely pathogenic/risk allele).

CONCLUSION

Local clinicians, as well as genetic counselors, with educational support as needed, can effectively return genetic results for PD as we observed favorable outcome measures in both groups. Increasing access to PD genetic testing and counseling is urgent; this can inform future efforts to integrate genetic testing and counseling into clinical care for all those with PD.

Genetic Testing in Parkinson's Disease

Genetic testing for persons with Parkinson's disease is becoming increasingly common. Significant gains have been made regarding genetic testing methods, and testing is becoming more readily available in clinical, research, and direct-to-consumer settings. Although the potential utility of clinical testing is expanding, there are currently no proven gene-targeted therapies, but clinical trials are underway. Furthermore, genetic testing practices vary widely, as do knowledge and attitudes of relevant stakeholders. The specter of testing mandates financial, ethical, and physician engagement, and there is a need for guidelines to help navigate the myriad of challenges. However, to develop guidelines, gaps and controversies need to be clearly identified and analyzed. To this end, we first reviewed recent literature and subsequently identified gaps and controversies, some of which were partially addressed in the literature, but many of which are not well delineated or researched. Key gaps and controversies include: (1) Is genetic testing appropriate in symptomatic and asymptomatic individuals without medical actionability? (2) How, if at all, should testing vary based on ethnicity? (3) What are the long-term outcomes of consumer- and research-based genetic testing in presymptomatic PD? (4) What resources are needed for clinical genetic testing, and how is this impacted by models of care and cost-benefit considerations? Addressing these issues will help facilitate the development of consensus and guidelines regarding the approach and access to genetic testing and counseling. This is also needed to guide a multidisciplinary approach that accounts for cultural, geographic, and socioeconomic factors in developing testing guidelines. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

An exploration of knowledge, risk perceptions, and communication in a family with multiple genetic risks for Parkinson's disease

Genomic testing increasingly challenges health care providers and patients to understand, share, and use information. The provision of polygenic risks is anticipated to complicate comprehension, communication, and risk perception further. This manuscript aims to illuminate the challenges confronting families with multiple genetic risks for Parkinson's disease. Identifying and planning for such issues may prove valuable to family members now and in the future, should neuroprotective or genotype-specific therapies become available. We present qualitative data from interviews with a multi-generational family carrying pathogenic variants in the glucocerebrosidase (GBA1) and leucine-rich repeat kinase 2 (LRRK2) genes which are associated with an increased risk for developing Parkinson's disease (PD). The family includes two brothers (heterozygous for LRRK2 p.G2019S and homozygous for GBA1 p.N409S) and their four descendants. The brothers were concordant for GD and discordant for PD. Genetic counseling and testing were provided to four of the six participants. Two years later, semi-structured interviews were conducted with the initial participants (n = 4) and two additional first-degree relatives. Interviews were transcribed and thematically analyzed, providing the basis for this report. Illuminated topics include the perceived risk of developing PD, recall of genetic information, and family communication. With the expanding use of exome and genome sequencing, we anticipate that genetic counselors will increasingly face the challenges demonstrated by this case involving multiple genetic risks for PD, limited data to clarify risk, and the inherent variability of family communication, genetic knowledge, and risk perception. This clinical case report provides a compelling narrative demonstrating the need for additional research exploring these multifaceted topics relevant to both families facing these challenges and providers striving to assist, support and guide their journey.

The Genetic Testing Experience of Individuals with Parkinson's Disease

Background

The perspective and experiences of individuals with Parkinson's disease (PD) regarding genetic testing is limited.

Objectives

To determine if anticipated benefits and negative consequences of genetic testing noted in prior studies have occurred in a surveyed group of patients with PD and to identify reasons why some individuals with PD have not had testing.

Methods

Individuals were surveyed from 22 support/advocacy groups throughout the US. Information about patient demographics and genetic testing were assessed, along with the consequences experienced after testing or anticipated by those who have not had testing. Descriptive statistics, Pearson correlation coefficient, ANOVA, and independent sample t-test were utilized for data analysis.

Results

Of the genetic testing group (n = 78), most received testing through a research study (44.9%) or a Direct-to-Consumer company (46.2%). Most did not meet with a genetic counselor before (87.2%) or after testing (64.1%). Fewer positive and fewer negative consequences were reported after testing compared to the consequences anticipated by those who have not undergone testing (P < 0.001, all comparisons). Of the non-genetic testing group (n = 166), 49.4% did not undergo testing because they were not aware it was available and 38.0% because their doctor did not offer it.

Conclusions

Findings demonstrate the need for providers to have genetic testing discussions with PD patients, who may otherwise seek testing via Direct-to-Consumer companies or be unaware it is available. Collaborations with genetic counselors trained in providing anticipatory guidance may assist patients in forming more realistic expectations regarding the consequences experienced after genetic testing for PD.

Return of individual research results from genomic research: A systematic review of stakeholder perspectives

Despite the plethora of empirical studies conducted to date, debate continues about whether and to what extent results should be returned to participants of genomic research. We aimed to systematically review the empirical literature exploring stakeholders’ perspectives on return of individual research results (IRR) from genomic research. We examined preferences for receiving or willingness to return IRR, and experiences with either receiving or returning them. The systematic searches were conducted across five major databases in August 2018 and repeated in April 2020, and included studies reporting findings from primary research regardless of method (quantitative, qualitative, mixed). Articles that related to the clinical setting were excluded. Our search identified 221 articles that met our search criteria. This included 118 quantitative, 69 qualitative and 34 mixed methods studies. These articles included a total number of 118,874 stakeholders with research participants (85,270/72%) and members of the general public (40,967/35%) being the largest groups represented. The articles spanned at least 22 different countries with most (144/65%) being from the USA. Most (76%) discussed clinical research projects, rather than biobanks. More than half (58%) gauged views that were hypothetical. We found overwhelming evidence of high interest in return of IRR from potential and actual genomic research participants. There is also a general willingness to provide such results by researchers and health professionals, although they tend to adopt a more cautious stance. While all results are desired to some degree, those that have the potential to change clinical management are generally prioritized by all stakeholders. Professional stakeholders appear more willing to return results that are reliable and clinically relevant than those that are less reliable and lack clinical relevance. The lack of evidence for significant enduring psychological harm and the clear benefits to some research participants suggest that researchers should be returning actionable IRRs to participants.

The Role of Genetic Testing for Parkinson's Disease

PURPOSE OF REVIEW

To describe current practices and attitudes about genetic testing for Parkinson's disease (PD) among neurologists, highlight the changing scene of genetic testing for PD, and provide guidance on facilitating PD genetic testing in a clinical practice.

RECENT FINDINGS

Since the 1990s, researchers have discovered several major gene variants contributing to PD etiology. A large body of literature now exists supporting the frequency of these variants in different populations and their effects on phenotype and clinical course. Recently, clinical trials have emerged with therapies targeting genetic forms of PD, specifically LRRK2 and GBA. Despite this growing knowledge, genetic testing for PD is not typically offered by neurologists including movement disorder specialists. Neurologists express concerns about the financial and practical issues of genetic testing as well as the potential impact on their patients. Researchers and specialists in the field are questioning this hesitation as clinical utility and consumer demand increase. Consideration of genetic testing for PD is shifting, as we enter a new era of precision medicine and gain clinical knowledge about PD. Barriers to testing, as perceived by clinicians, can be overcome with education, support, and involvement of multiple stakeholders with the goal of making PD genetic testing accessible to all patients.