Factors related to genetic testing in adults at risk for Huntington disease: the prospective Huntington at-risk observational study (PHAROS)

Social cognition and quality of life in Huntington's disease

Individuals with Huntington's disease (HD) and their close others report difficulties with social interaction, and previous studies have shown that the areas of quality of life detrimentally impacted by HD include social and emotional domains. However, despite the finding that people with HD often exhibit difficulties on standard tests of social cognition, the relationship between such impairments and patients' everyday life has remained largely unexplored. We used a range of tasks assessing empathy, emotion recognition and Theory of Mind, to investigate whether patients' performance may predict quality of life within the social and emotional domains, while also accounting for broader cognitive function, behavioural changes, motor symptoms, disease stage and functional capacity. Poorer social functioning was predicted specifically by a reduced tendency to attribute intentionality while viewing social animations, in addition to emotional blunting and apathy, while role limitations due to emotional problems were predicted by personal distress, irritability and aspects of executive function. These findings highlight the potential impact of Theory of Mind impairment on quality of life in HD, and suggest that enhanced assessment of social cognition will offer unique insight into patients' social function and related wellbeing.

Alcohol Use, Mental Health, and Functional Capacity as Predictors of Workplace Disability in a Cohort With Manifest Huntington's Disease

OBJECTIVE

Huntington's disease (HD) is an inherited neurodegenerative disease involving motor, cognitive, psychiatric, and behavioral impairments that eventually affect work-role functioning. There is limited research regarding predictors of workplace disability in HD. The authors examined predictors of work impairment and disability in a cross-sectional cohort of employed persons with symptomatic HD participating in the worldwide Enroll-HD study.

METHODS

The study sample (N=316) comprised individuals with manifest HD and a CAG repeat length range between 39 and 60 and were currently engaged in paid full- or part-time employment. Univariate and multivariate logistic regression analyses identified predictors and the effect of all predictors in a fully adjusted model.

RESULTS

Of the sample, 20.3% reported missing work due to HD, 60.1% reported experiencing impairment while working due to HD, 79.1% reported having work-related activity impairment due to HD, and 60.8% reported impairment in overall work productivity due to HD. Individuals had 25% higher odds of missing work time if they had a higher level of functional impairment (odds ratio=0.76, 95% CI=0.64, 0.91) and had three times greater odds of missing work if they were current alcohol drinkers, compared with nondrinkers (odds ratio=2.86, 95% CI=1.62, 5.03). Individuals with lower self-perceived mental health were also 5% more likely to experience impairment at work due to HD. Motor impairment was not a strong predictor of workplace disability.

CONCLUSIONS

These findings provide important new knowledge that can inform the development of strategies or targeted intervention trials to support persons with symptomatic HD to maintain their work roles.

Genetic counseling and testing practices for late-onset neurodegenerative disease: a systematic review

Objective

To understand contemporary genetic counseling and testing practices for late-onset neurodegenerative diseases (LONDs), and identify whether practices address the internationally accepted goals of genetic counseling: interpretation, counseling, education, and support.

Methods

Four databases were systematically searched for articles published from 2009 to 2020. Peer-reviewed research articles in English that reported research and clinical genetic counseling and testing practices for LONDs were included. A narrative synthesis was conducted to describe different practices and map genetic counseling activities to the goals. Risk of bias was assessed using the Qualsyst tool. The protocol was registered with PROSPERO (CRD42019121421).

Results

Sixty-one studies from 68 papers were included. Most papers focused on predictive testing (58/68) and Huntington’s disease (41/68). There was variation between papers in study design, study population, outcomes, interventions, and settings. Although there were commonalities, novel and inconsistent genetic counseling practices were identified. Eighteen papers addressed all four goals of genetic counseling.

Conclusion

Contemporary genetic counseling and testing practices for LONDs are varied and informed by regional differences and the presence of different health providers. A flexible, multidisciplinary, client- and family-centered care continues to emerge. As genetic testing becomes a routine part of care for patients (and their relatives), health providers must balance their limited time and resources with ensuring clients are safely and effectively counseled, and all four genetic counseling goals are addressed. Areas of further research include diagnostic and reproductive genetic counseling/testing practices, evaluations of novel approaches to care, and the role and use of different health providers in practice.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00415-021-10461-5.

Predictive testing for neurodegenerative diseases in the age of next-generation sequencing

The availability and cost of next-generation sequencing (NSG) now allow testing large numbers of genes simultaneously. However, the gold standard for predictive testing has been to test only for a known family mutation or confirmed family disease. The goal of this study was to investigate the psychological impact of predictive testing for autosomal dominant neurodegenerative diseases without a known family mutation using next-generation sequencing panels compared to single-gene testing of a known family mutation. Fourteen individuals from families with a known mutation and 10 individuals with unknown family mutations participated. Participants completed questionnaires on demographics, genetic knowledge, and psychological measures of anxiety, depression, perceived personal control, rumination, and intolerance to uncertainty at baseline and 1 and 6 months after receiving results. Decision regret was measured 1 and 6 months after receiving results. Participants completed a modified Huntington disease genetic testing protocol with genetic counseling and neurological and psychological evaluation. Genetic testing of either the known family mutation or an NGS panel of neurodegenerative disease genes was performed. Semi-structured interviews were performed at 6 months post-results about their experience. Two-sample t tests were performed on data collected at each time point to identify significant between-group differences in demographic variables, baseline psychological scores, and baseline genetic knowledge scores. Within-group change over time was assessed by a mixed-effects model. Results of this study indicate that NGS panels for predictive testing for neurodegenerative disease are safe and beneficial to participants when performed within a modified HD protocol. Though significant differences in psychological outcomes were found, these differences may have been driven by genetic results and baseline psychological differences between individuals within the groups. Participants did not regret their decision to test and were largely pleased with the testing protocol.

Predictive Genetic Counseling for Neurodegenerative Diseases: Past, Present, and Future

Predictive genetic counseling for neurodegenerative diseases commenced with Huntington's disease (HD). Because the psychological issues and outcomes have been best studied in HD, the HD genetic counseling and testing protocol is still accepted as the gold standard for genetic counseling for these diseases. Yet, advances in genomic technology have produced an abundance of new information about the genetics of diseases such as Alzheimer's disease, frontotemporal dementia, amyotrophic lateral sclerosis, and Parkinson's disease. The resulting expansion of genetic tests together with the availability of direct-to-consumer testing and clinical trials for treatment of these diseases present new ethical and practical issues requiring modifications to the protocol for HD counseling and new demands on both physicians and genetic counselors. This work reviews the history of genetic counseling for neurodegenerative diseases, its current practice, and the future direction of genetic counseling for these conditions.

The Ripple Effect: A Qualitative Overview of Challenges When Growing Up in Families Affected by Huntington's Disease

BACKGROUND

The average age for the onset of Huntington's disease (HD) is an age when many people have children and caretaking responsibilities; HD is therefore likely to impact the whole family, including children and adolescents. Despite an increased understanding of the challenges for young people of growing up in a family affected by HD, a continuing lack of available knowledge has led to inadequate youth-focused support in many countries.

OBJECTIVE

This study explored the risks of growing up in a family affected by HD, and provided a participant-generated overview of the main challenges the participants experienced, in order to enhance awareness and promote more youth-focused support.

METHODS

As part of a larger national study, this qualitative paper included 36 semi-structured interviews with young people and adults who had previous or current experiences of growing up in families affected by HD. The interviews were analysed using thematic analysis.

RESULTS

The participants described challenges relating to four main domains of everyday life: family functioning, emotions and reactions, social functioning, and public and care services.

CONCLUSION

This study contributes to an increased understanding of risk factors posed on young people by growing up with a parent with HD. The study highlighted challenges in several areas of life presenting a risk to the overall health and functioning of young people. We propose that this knowledge should be applied within a bioecological framework, to increase understanding and promote awareness of the possible risks posed, for young people, by HD.

Huntington's Disease in a Patient Misdiagnosed as Conversion Disorder

Huntington's disease (HD) is an inherited, progressive, and neurodegenerative neuropsychiatric disorder caused by the expansion of cytosine-adenine-guanine (CAG) trinucleotide in Interested Transcript (IT) 15 gene on chromosome 4. This pathology typically presents in individuals aged between 30 and 50 years and the age of onset is inversely correlated with the length of the CAG repeat expansion. It is characterized by chorea, cognitive deficits, and psychiatric symptoms. Usually the psychiatric disorders precede motor and cognitive impairment, Major Depressive Disorder and anxiety disorders being the most common presentations. We present a clinical case of a 65-year-old woman admitted to our Psychiatric Acute Unit. During the 6 years preceding the admission, the patient had clinical assessments made several times by different specialties that focused only on isolated symptoms, disregarding the syndrome as a whole. In the course of her last admission, the patient was referred to our Neuropsychiatric Team, which made the provisional diagnosis of late-onset Huntington's disease, later confirmed by genetic testing. This clinical vignette highlights the importance of a multidisciplinary approach to atypical clinical presentations and raises awareness for the relevance of investigating carefully motor symptoms in psychiatric patients.

Relationships Among Apathy, Health-Related Quality of Life, and Function in Huntington's Disease

Up to 90% of individuals with Huntington's disease (HD)-a progressive, inherited neurodegenerative disorder-experience apathy. Apathy is particularly debilitating because it is marked by a reduction in goal-directed behaviors, including self-care, social interactions, and mobility. The objective of this study was to examine relationships between variables of apathy, functional status, physical function, cognitive function, behavioral status/emotional function, and health-related quality of life. Clinician-rated measures of physical, cognitive, and behavioral function, including one clinician-rated item on apathy, and self-reported measures of physical function, health-related quality of life, and emotional, cognitive, and social function were collected in a single session from 487 persons with the HD mutation (prodromal, N=193; early-stage manifest, N=186; late-stage manifest, N=108). Multiple linear regression models were used to examine which outcomes best predicted clinician-rated apathy after controlling for disease stage. Greater apathy related to less independence, increased motor impairment, and more clinician-rated behavioral problems (i.e., anger, irritability, depression). Similarly, poorer self-reported health-related quality of life; greater chorea; greater upper- and lower-extremity dysfunction; greater speech and swallowing dysfunction; worse anxiety, depression, and behavioral dyscontrol; worse cognitive function; and less satisfaction with social roles related to greater apathy. In conclusion, apathy related to physical, cognitive, and behavioral dysfunction across disease stages. Future work should explore whether clinical interventions targeting different functional domains may have the potential to reduce apathy in this patient population.

Huntington Disease as a Neurodevelopmental Disorder and Early Signs of the Disease in Stem Cells

Huntington disease (HD) is a dominantly inherited disorder caused by a CAG expansion mutation in the huntingtin (HTT) gene, which results in the HTT protein that contains an expanded polyglutamine tract. The adult form of HD exhibits a late onset of the fully symptomatic phase. However, there is also a long presymptomatic phase, which has been increasingly investigated and recognized as important for the disease development. Moreover, the juvenile form of HD, evoked by a higher number of CAG repeats, resembles a neurodevelopmental disorder and has recently been the focus of additional interest. Multiple lines of data, such as the developmental necessity of HTT, its role in the cell cycle and neurogenesis, and findings from pluripotent stem cells, suggest the existence of a neurodevelopmental component in HD pathogenesis. Therefore, we discuss the early molecular pathogenesis of HD in pluripotent and neural stem cells, with respect to the neurodevelopmental aspects of HD.