Protocol for genetic testing in Huntington disease: three years of experience in Minnesota

Genetic counseling and testing for Huntington's disease: A historical review

This manuscript describes the ways in which genetic counseling has evolved since John Pearson and Sheldon Reed first promoted "a genetic education" in the 1950s as a voluntary, non-directive clinical tool for permitting individual decision making. It reviews how the emergence of Huntington's disease (HD) registries and patient support organizations, genetic testing, and the discovery of a disease-causing CAG repeat expansion changed the contours of genetic counseling for families with HD. It also reviews the guidelines, outcomes, ethical and laboratory challenges, and uptake of predictive, prenatal, and preimplantation testing, and it casts a vision for how clinicians can better make use of genetic counseling to reach a broader pool of families that may be affected by HD and to ensure that genetic counseling is associated with the best levels of care. © 2016 Wiley Periodicals, Inc.

[Current status of the predictive genetic testing for hereditary neurological diseases in Shinshu University Hospital]

The current status of predictive genetic testing for late-onset hereditary neurological diseases in Japan is largely unknown. In this study, we analyzed data from 73 clients who visited the Division of Clinical and Molecular Genetics, Shinshu University Hospital, for the purpose of predictive genetic testing. The clients consisted of individuals with family histories of familial amyloid polyneuropathy (FAP; n=30), Huntington's disease (HD; n=16), spinocerebellar degeneration (SCD; n=14), myotonic dystrophy type 1 (DM1; n=9), familial amyotrophic lateral sclerosis type 1 (ALS1; n=3), and Alzheimer's disease (AD; n=1). Forty-nine of the 73 (67.1%) clients were in their twenties or thirties. Twenty-seven of the 73 (37.0%) clients visited a medical institution within 3 months after becoming aware of predictive genetic testing. The most common reason for requesting predictive genetic testing was a need for certainty or to reduce uncertainty and anxiety. The decision-making about marriage and having a child was also a main reason in clients in the twenties and thirties. The numbers of clients who actually underwent predictive genetic testing was 22 of 30 (73.3%) in FAP, 3 of 16 (18.8%) in HD, 6 of 10 (60.0%) in SCD, 7 of 9 (77.8%) in DM1, and 0 of 3 (0%) in ALS1 (responsible gene of the disease was unknown in 4 SCD patients and an AD patient). The percentage of test usage was lower in untreatable diseases such as HD and SCD than that in FAP, suggesting that many clients changed their way of thinking on the significance of testing through multiple genetic counseling sessions. In addition, it was obvious that existence of disease-modifying therapy promoted usage of predictive genetic testing in FAP. Improvement of genetic counseling system to manage predictive genetic testing is necessary, as consultation concerning predictive genetic testing is the main motivation to visit genetic counseling clinic in many at-risk clients.

"You're one of us now": young people describe their experiences of predictive genetic testing for Huntington disease (HD) and familial adenomatous polyposis (FAP)

There has been much debate about the psychosocial effects of predictive genetic testing in minors. The majority of this debate has been theoretical, with little empirical evidence published. We conducted in-depth interviews with 18 young people who had undergone testing, to explore the range of harms and benefits that they perceived were associated with their tests. Participants were eight individuals who were tested for Huntington disease (two gene-positive, six gene-negative) and ten who were tested for familial adenomatous polyposis (five gene-positive, five gene-negative). At the time of their test they ranged from 10 to 25 years of age. When interviewed they ranged from 14 to 26 years of age. Harms described included knowledge of future illness, witnessing distress in parents, negative effects on family relationships and friendships, effects upon employment and school, experiencing regret, feeling guilty and having to confront difficult issues. Benefits included knowledge of gene-negative status, relief from uncertainty, witnessing relief in parents, feeling able to plan for the future, positive effects on family relationships and friendships, feeling empowered and experiencing a sense of clarity about what is important in life. Harms were described in relation to gene-negative test results, as were benefits in relation to gene-positive test results. The testing process itself had several positive and negative effects for young people, distinct from the actual test result. Future research concerning the effects of predictive genetic testing in young people must remain broad and should aim to measure the beneficial as well as the harmful effects that resonate for young people themselves.

Psychological Aspects of Presymptomatic Diagnosis of Spinocerebellar Ataxia Type 2 in Cuba

OBJECTIVE

In this paper, we present a descriptive study of the first year of implementation of the predictive genetic testing program for spinocerebellar ataxia type 2 (SCA2) in Cuba, which has been structured along the international guidelines for Huntington disease.

SUBJECTS AND METHODS

Medical records were retrospectively reviewed from 100 individuals who requested presymptomatic diagnosis. They had been seen between February 2001 and May 2002 at the Ataxia Clinic in the province of Holguín and had completed the protocol. The participants had psychological evaluations before testing and 1 week after being informed of the result.

RESULTS

The average age of the participants in the presymptomatic testing for SCA2 was 39.3 years, 62% were female. The main reasons for taking the test were family planning and risk assessment in their children. Family participation in the process was high and there were several additional sources of social support. Before the test, the subjects did not present high levels of anxiety or depression. On informing the patients of the test results indicators for anxiety and depression significantly decreased, and there were no significant differences according to whether the test result had been positive or negative. Catastrophic events were rare during the first week after the test.

CONCLUSIONS

The results indicate a strong interest in presymptomatic diagnosis among individuals at risk for SCA2 in Holguín and a lack of significant psychological drawbacks up to 1 week after information of results.

Psychological consequences and predictors of adverse events in the first 5 years after predictive testing for Huntington's disease

The promise of genetic medicine is to provide information, based on genotype, to persons not yet sick about their risk of future illness. However, little is known of the long-term psychological effects for asymptomatic persons learning their risk of having a serious disease. Predictive genetic testing for Huntington's disease (HD) has been offered for the longest time for any disease. In the present study, the psychological consequences of predictive testing were assessed prospectively in individuals at risk for HD during seven visits over 5 years. Questionnaires of standard measures of psychological distress (the General Severity Index of the Symptom Check List-90-Revised), depression (the Beck Depression Inventory), and general well-being (the General Well-Being Scale) were administered to the participants. A significant reduction in psychological distress was observed for both result groups throughout 2 years (p < 0.001) and at 5 years (p = 0.002). Despite the overall improvement of the psychological well-being, 6.9% (14 of 202) of the participants experienced an adverse event during the first 2 years after predictive testing that was clinically significant. The frequency of all defined adverse events in the participants was 21.8%, with higher frequency in the increased risk group (p = 0.03) and most occurring within 12 months of receiving results.

A hereditary disorder in the family and the family life cycle: Huntington disease as a paradigm

The implications of predictive DNA-testing for Huntington's Disease (HD) for the transitions in the family life cycle are described. HD is a hereditary disorder leading to personality changes, uncontrollable movements, cognitive impairment, and ultimately death in mostly adults. People at risk have the possibility to detect whether or not they carry the disease provoking-gene, but no treatment is available. In this article, we will highlight the complex implications of pre-symptomatic testing by describing six different cases, interpreted by following the theoretical framework of Carter and McGoldrick (see pp. 684). HD interferes strongly with the "normal" transitions in the life cycle. It is not so much the test result itself that may be disrupting, but the changed expectations and possibilities for the future. As a family disease, HD forces its members to cope, one way or another, with disturbing events and untimely deaths. Some families are able to make some transitions, while becoming blocked at other transition points; this may differ between families. Being able to cope with HD in the family for a certain time does not necessarily imply that problems will never occur. Because any family member may eventually need help, it is important to then help the family discover what hinders them from making the transition to the next life stage, and to resolve these issues so that they can move on.

A worldwide assessment of the frequency of suicide, suicide attempts, or psychiatric hospitalization after predictive testing for Huntington disease

Prior to the implementation of predictive-testing programs for Huntington disease (HD), significant concern was raised concerning the likelihood of catastrophic events (CEs), particularly in those persons receiving an increased-risk result. We have investigated the frequency of CEs-that is, suicide, suicide attempt, and psychiatric hospitalization-after an HD predictive-testing result, through questionnaires sent to predictive-testing centers worldwide. A total of 44 persons (0.97%) in a cohort of 4,527 test participants had a CE: 5 successful suicides, 21 suicide attempts, and 18 hospitalizations for psychiatric reasons. All persons committing suicide had signs of HD, whereas 11 (52.4%) of 21 persons attempting suicide and 8 (44.4%) of 18 who had a psychiatric hospitalization were symptomatic. A total of 11 (84.6%) of 13 asymptomatic persons who experienced a CE during the first year after HD predictive testing received an increased-risk result. Factors associated with an increased risk of a CE included (a) a psychiatric history </=5 years prior to testing and (b) unemployed status. The frequency of CEs did not differ between those persons receiving results of predictive testing through linkage analysis in whom there was only changes in direction of risk and those persons receiving definitive results after analysis for the mutation underlying HD. These findings provide insights into the frequency, associated factors, and timing of CEs in a worldwide cohort of persons receiving predictive-testing results and, as such, highlight persons for whom ongoing support may be beneficial.

Psychological impact of screening for familial ovarian cancer: reactions to initial assessment

OBJECTIVES

To assess the psychological impact on women attending a familial ovarian cancer screening clinic.

STUDY METHODS

157 women referred for screening completed an investigator designed questionnaire, the Spielberger State Trait Anxiety Scale and the Centre for Epidemiological Studies Depression Scale prior to the screening interview and an eight-item questionnaire post-assessment.

RESULTS

95.4% saw the screening as valuable. Thirty-one point four percent of all patients scored about the cutoff point for depression. Sixteen percent exhibited high levels of anxiety. Fifty-six point four percent of patients accurately perceived their risk. Twenty-one point five percent of those who accurately perceived themselves as being at high risk had high anxiety and 40.6% reported significant depressive symptoms. Of the 26.5% of patients who overestimated their risks, 40.0% reported significant depressive symptoms and 22.6% were anxious. Of the 17.1% who minimized their risk, none were anxious (0.0%), and only 15.8% were depressed.

CONCLUSION

Attendees at a familial ovarian cancer screening clinic may have high levels of depression and anxiety.

Knowledge of genetics and attitudes toward genetic testing in two hereditary ataxia (SCA 1) kindreds

Molecular genetic predictive or prenatal genetic testing is now possible in families with one form of adult-onset, autosomal dominant ataxia (SCA 1). Before the SCA 1 gene was isolated, we began a study of the knowledge of genetics, the perception of the disease, and the intended use of genetic testing among members of two large SCA 1 kindreds. Questionnaires were sent to 210 consenting affected, at-risk, and spouse members of two SCA 1 kindreds; data from the 117 respondents were analyzed on a personal computer. Sixty-nine percent of respondents thought predictive testing (by genetic linkage) should be made available immediately, and 42% thought prenatal testing should be made available. The kindreds differed in several important aspects: knowledge of genetic concepts, family size, and anticipated emotional responses to genetic testing. No respondent had obtained individualized genetic counseling. There is moderate interest in genetic testing for this fatal neurodegenerative disease of adulthood. Members of our kindreds have not received genetic counseling outside of the research setting. Finally, factors specific to a particular kindred may influence or predict individual responses to genetic testing.

Self-selection in predictive testing for Huntington's disease

Several studies have reported favorable psychological reactions to predictive testing for Huntington's disease (HD). However, few at-risk persons have been tested, and there is evidence that some at-risk people avoid testing because they fear being unable to cope with the information. Favorable psychological reactions may result from self-selection of persons who believe they are better-equipped to handle "bad news." We surveyed 32 at-risk persons who had considered, but not chosen, testing and 66 persons who had been previously tested. Twelve persons decided not to be tested (No group); 20 persons postponed testing until some later date (Maybe group). Of the two untested groups, a significantly greater number of the No group had not been tested because they anticipated problems associated with their emotional reactions. The persons in the Tested group had less often anticipated problems with their emotional reactions; and among the minority who had anticipated some problems, most did not question their ability to cope. We conclude that the Tested persons are psychologically selected for favorable responses to genetic testing. Surveys of health professionals suggest that a sizable minority would disclose genetic disease risk whether or not people want it. Thus, people who would not choose to be tested might be persuaded to do so, or have results thrust upon them. We should be wary about assuming that the generally favorable reactions to HD testing will continue when testing becomes more widespread, as is likely to happen with simplification of the technology and acceptance of these tests by the medical community.

Predictive testing for Huntington disease: social characteristics and knowledge of applicants, attitudes to the test procedure and decisions made after testing

An investigation has been made of the social characteristics and knowledge and experience of Huntington disease (HD) for the first 80 individuals considering presymptomatic testing (applicants) at the medical genetics centres in Edinburgh and Glasgow and of attitudes to the test procedure and decisions made after testing for those who received a result. Sixty-one percent of applicants were female and 31% were over 40 years old. Almost all had a symptomatic parent but 38% did not know HD was in their family until they were over 25 years old and 48% had never received genetic counselling. Thirty-eight percent of applicants first heard of the test at the genetic clinic, 20% from a relative and 20% from the media, but none had received information from their GP. Thirty-one applicants did not have the test because they voluntarily withdrew (17 individuals), their family structure was unsuitable or no informative result was possible (11 individuals), or they were diagnosed clinically as being affected (3 individuals). Those who voluntarily withdrew did not differ significantly from the 49 who received a result in social characteristics or knowledge and experience of HD. Twenty-two individuals were found to be at increased risk (IR) (> 50% of becoming affected) and 27 to be at decreased risk (DR) (< 50% of becoming affected). There was a median period of 9 months between entering the test procedure and receiving a result and the main criticism of the procedure was that it took too long to complete and several individuals experienced considerable anxiety while awaiting their result.(ABSTRACT TRUNCATED AT 250 WORDS)

Informed consent and Huntington disease: a model for communication

American and Canadian professional accreditation standards for medical genetics, and genetic counseling require certain abilities with regard to "communication." What remains unclear is how such standards are to be interpreted in terms of appropriate clinical protocols, objectives, and values. These issues have significant medical and legal implications, particularly with regard to medical malpractice. From the perspective of genetic testing for Huntington disease, this paper identifies those clinical objectives and practices which may be described as constituting the appropriate standard of care for "communication," and informed consent.