Long-term impact of Huntington disease linkage testing

We performed a long-term follow-up of Huntington disease (HD) predictive testing (an average of 6 years post-test) for 16 of 20 people who received informative linkage test results. Although no pre-test or baseline psychological differences were noted between those with an increased versus a decreased risk of HD, the long-term impact was dramatically different in these two groups. The low-risk group reported less uncertainty, anxiety or worry, fear, and worry about children's risk, whereas the high-risk group reported either the same or increased concern in these areas. Those at low risk also acknowledged an increased sense of control and self-esteem, whereas those at high risk reported decreases or no changes. One high-risk individual reported chronic depression that had occurred since the testing. Additionally, those at low risk reported greater reliance and faith in spiritual or religious beliefs than those at high risk. The emotional impact of HD genetic testing justifies the continued utilization of pre- and post-test counseling protocols. Pre-test counseling should include discussion of the known risks and benefits of predictive testing, with special emphasis on the participant's expectations for future change and improvement. Although the psychological impact appears mostly favorable for those with decreased risk, there is risk for a decline in psychological well-being over time for those with an increased risk for HD. Am J. Med. Genet. 70:365–370, 1997. © 1997 Wiley-Liss, Inc.     

Predictive,pre-natal and diagnostic genetic testing for Huntington's disease: the experience in Canada from 1987 to 2000

Predictive and pre-natal testing for Huntington's Disease (HD) has been available since 1987. Initially this was offered by linkage analysis, which was surpassed by the advent of the direct mutation test for HD in 1993. Direct mutation analysis provided an accurate test that not only enhanced predictive and pre-natal testing, but also permitted the diagnostic testing of symptomatic individuals. The objective of this study was to investigate the uptake, utilization, and outcome of predictive, pre-natal and diagnostic testing in Canada from 1987 to April 1, 2000. A retrospective design was used; all Canadian medical genetics centres and their affiliated laboratories offering genetic testing for HD were invited to participate. A total of 15 of 22 centres (68.2%), currently offering or ever having offered genetic testing for HD, responded, providing data on test results, demographics, and clinical history. A total of 1061 predictive tests, 15 pre-natal tests, and 626 diagnostic tests were performed. The uptake for predictive testing was approximately 18% of the estimated at-risk Canadian population, ranging from 12.5% in the Maritimes to 20.7% in British Columbia. There appears to have been a decline in the rate of testing in recent years. Of the predictive tests, 45.0% of individuals were found to have an increased risk, and a preponderance of females (60.2%) sought testing. A greater proportion of those at < or = 25% risk sought predictive testing once direct CAG mutation analysis had become available (10.9% after mutation analysis vs 4.7% before mutation analysis, p = 0.0077). Very few pre-natal tests were requested. Of the 15 pre-natal tests, 12 had an increased risk, resulting in termination of pregnancy in all but one. Diagnostic testing identified 68.5% of individuals to be positive by mutation analysis, while 31.5% of those with HD-like symptoms were not found to have the HD mutation. The positive diagnostic tests included 24.5% of individuals with no known prior family history of HD.     

Psychological aspects of pre-symptomatic testing for Machado-Joseph disease and familial amyloid polyneuropathy type I

Machado-Joseph disease [MJD, also spinocerebellar ataxia type 3 (SCA3)] and familial amyloid polyneuropathy type I (FAP-I or ATTR V30M) are neurodegenerative disorders, inherited in an autosomal dominant fashion, which have a high prevalence in Portugal, probably due to a founder effect. MJD and FAP-I are late-onset diseases, with symptoms emerging usually during adulthood. CGPP, which is the national reference centre for these disorders, has a genetic lab that offers diagnostic, pre-symptomatic and prenatal testing and an outpatient clinic to counsel and follow relatives at risk for hereditary ataxias, FAP-I and Huntington disease (HD). The present work is a review of our 10-year experience with psychological counselling of individuals at risk for MJD and FAP-I. Persons at risk for FAP-I may show a better response to pre-symptomatic testing than those who are at risk for MJD and HD because of the availability of liver transplantation, which may improve their health and life expectancy. Psychological well-being and specific distress of MJD and FAP-I test applicants, before undergoing genetic testing (baseline level) and 3 to 6 months after disclosure of test results, have shown a low level of change, both in identified carriers and non-carriers. A major goal of psychological characterization of at-risk individuals for MJD and FAP-I is to determine the factors that influence the uptake of genetic testing.     

Attitudes of neurologists, psychiatrists, and psychotherapists towards predictive testing for Huntington''s disease in Germany.

Predictive testing for Huntington's disease (HD) in Germany is performed by genetic counsellors, neurologists, psychiatrists, and psychotherapists. In order to evaluate the attitudes of neurologists, psychiatrists, and psychotherapists in Germany towards predictive testing for HD, a postal questionnaire was sent to this group. Two German Bundesländer were chosen, Baden Württemberg (BW) and Niedersachsen (NS). Of 469 persons interviewed the response rate was 32.6%. The questionnaire consisted of 17 items assessing sociodemographic data, acquaintance with HD patients, lay organisations, attitudes towards genetic counselling, presymptomatic and prenatal DNA testing, and reproduction of persons at risk for HD. More than 70% of the subjects were well informed about predictive DNA testing but knowledge about the details of the test procedure, especially the World Federation of Neurology (WFN) and International Huntington Association (IHA)1 recommendations, was quite low (11.8%). Nevertheless, the majority would recommend predictive testing for HD although they anticipated problems for the probands. The majority of our respondents favoured psychological test and post-test counselling for those tested. Concerning reproduction, most subjects favoured prenatal testing or that persons at risk should refrain from having children. We found that the opinions of practitioners and at risk persons differed with respect to the predictive DNA test and, particularly, to prenatal testing. Therefore the testing procedure could be improved if practitioners were better informed about the DNA test in general and about the attitudes and wishes of their patients.     

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. One year after receiving their result, almost 40% of individuals had made major life decisions, mainly in the areas of personal relationships, career and financial matters and over a third of fecund individuals in both IR and DR groups had changed their decision about future childbearing. Eighty-five percent of the IR group and 53% of the DR group requested continued follow up after the 1-year follow-up visit. The majority wanted follow up by the genetic clinician, but we have found that in practice many individuals do not attend when offered clinic appointments after this time.     

Five year study of prenatal testing for Huntington''s disease: demand, attitudes, and psychological assessment.

Adult predictive and prenatal testing programmes for Huntington's disease (HD) in Canada have been available since 1986. However, the demand for prenatal testing and the reasons why some people choose not to have the prenatal test for this late onset disorder have not been well documented. In addition, the knowledge and attitudes of adult predictive testing candidates and their partners about prenatal testing are not well known nor are the psychological effects of prenatal testing well understood. As of September 1991, 425 subjects had entered the Canadian Collaborative Study of Predictive Testing and, of these, 47 subjects or their partners had become pregnant. Of this group, 14 (30%) couples requested prenatal testing, 24 (51%) couples did not want prenatal testing, and nine (19%) at risk subjects had already received a decreased risk through adult predictive testing and, therefore, were not eligible for the prenatal test. Of the 14 couples who initially requested prenatal testing, seven withdrew. Thus, demand for the prenatal test by eligible candidates was 7/38 or 18%, which is much lower than the 32 to 65% expected based on early survey data. The most frequently cited reason for declining prenatal testing was the hope that a cure would be found in time for their children. While the majority of adult predictive testing candidates (71%) in our study had accurate information about definitive prenatal testing, many (63%) did not have a correct understanding of exclusion prenatal testing. Although no serious adverse events such as suicide planning or admission to psychiatric hospital have occurred, a particular need for careful counselling was identified for those at risk candidates and their partners who have one prenatal test and feel compelled to use the test again in future pregnancies. Even though prenatal testing for HD is not requested as often originally expected, it still remains a desired option for some at risk persons and their partners.     

The choice not to undergo genetic testing for Huntington disease: Results from the PHAROS study

Rates of genetic testing in Huntington disease (HD) are lower than was predicted before direct DNA testing became available. Clinicians often do not have in-depth conversations with people at risk who chose not to test. We queried 733 research subjects who chose not to learn their HD gene status when enrolling in the Prospective Huntington At-Risk Observational Study, carried out between 1999 and 2008. Lack of an effective cure or treatment (66% of subjects) and inability to undo knowledge (66%) were the major reasons cited for choosing not to undergo HD DNA testing. Most subjects were not concerned about the length or burden of the testing process (61% and 59%, respectively). Subjects were optimistic that a treatment to improve symptoms or postpone onset would be developed within the next 10 years (56% and 53%, respectively), but they had less certainty about the prospects to prevent HD onset (36%). This is the first large, systematic study of why people at risk for HD choose not to undergo genetic testing. Attitudes about how people at risk for HD approach this life-altering choice should be reassessed as new treatments develop, and as clinical trials now require genetic testing at entry.     

Psychological functioning before predictive testing for Huntington's disease: the role of the parental disease, risk perception, and subjective proximity of the disease

BACKGROUND: Psychometric testing of participants in predictive DNA testing for Huntington's disease (HD) has shown that 15% of the subjects at risk for HD had at least mild depression or a high score for general anxiety or both in the pre-test period. The main aim of the study was the delineation of variables associated with pre-test distress of applicants for predictive testing for HD. Based on theoretical considerations, four specific hypotheses were tested regarding the role of (1) the test participant's age at the (perceived) parental onset of HD, (2) the affected parent's sex, (3) the perception of the risk for HD, and (4) the subjective proximity of the disease. Secondly, these four variables were used in multiple regression analyses to select the best predictors of pre- and post-test psychological functioning (one year after the test). Increasing the understanding of pre- and post-test distress is important for developing better counselling and support strategies for test applicants. METHODS: Data were collected by means of clinical interviews and psychometric questionnaires during the pre- and post-test (one year after the test) counselling sessions for predictive testing for HD. RESULTS: We found significant associations of the participant's age at the parental onset, the subjective proximity of the disease onset, and the perceived risk with pre-test psychometric measures of psychological functioning. Multiple regression analyses showed that the best predictors of pre-test functioning were the perceived proximity of the disease onset and its interaction with risk perception. Regarding post-test functioning, none of the proposed variables had a unique contribution beyond that accounted for by pre-test psychological functioning. CONCLUSIONS: Test participants who are close to the perceived age of onset of HD and who have a pessimistic risk perception should be given special attention during pre-test counselling because of their possible negative affective condition at that time. Pre-test psychological measures were the best predictors of post-test distress, irrespective of the test result. Suggestions for future longitudinal research are formulated. This kind of research should enable clinical geneticists and mental health professionals to refine the pre- and post-test counselling strategies for predictive DNA testing, not only for HD, but also for other incurable late onset disorders.     

Mental health and quality of life after genetic testing for Huntington disease: a long-term effect study in Germany

Predictive genetic testing for Huntington disease (HD) might cause severe short-term psychological reactions in patients with poor mental health. Very few studies exist on the long-term effects of genetic HD testing. The aim of this study was to assess mental health and quality of life in persons who were tested for HD mutation, to compare mental health depending on the result of the genetic test (non-carriers, gene carriers, and patients with HD) and to identify predictors of mental health and quality of life via linear regression. The data were collected by self-report questionnaires. In total, 121 individuals participated in this study: 52 were non-carriers, 54 were gene carriers, and 15 were gene carriers suffering from HD. Non-carriers and gene carriers showed better mental health and quality of life than HD-patients but did not differ from each other. In non-carriers four variables predicted increased depression and low mental quality of life: low perceived social support, no intimate relationship, female sex and younger age. For gene carriers three predictors were found: low perceived social support, the expectation of an unfavorable genetic test result before the testing procedure and being childless. To prevent detrimental effects of HD testing on mental health and mental quality of life, specific attention should be paid to persons with limited social networks during genetic counseling. Assessment of expectations related to the test result and mental health prior to a genetic testing procedure may help to identify gene carriers at risk of poor coping after an unfavorable test result.     

Engagement with genetic discrimination: concerns and experiences in the context of Huntington disease

It has been over 20 years since the inception of predictive testing for Huntington disease (HD), yet the social implications of knowing one's genetic risk for HD have not been fully explored. Genetic discrimination (GD) is a potential risk associated with predictive testing. Although anecdotal reports of GD have been documented, there is a paucity of research on the nature and experiences of GD in the context of HD. The purpose of this study was to describe the concerns and experiences of GD in the HD community. Semistructured interviews were conducted with 45 genetically tested and 10 untested individuals and analyzed using grounded theory methods. Our findings demonstrate that a majority of individuals were concerned about (37/55) and experienced GD (32/55) across a variety of contexts that extend beyond the traditionally examined contexts of insurance and employment to include family, social, government, and health-care domains. We describe a process of engagement with GD in which individuals formed meaningful interpretations of GD and personalized its risk and consequences in their lives. Our findings provide an insight into some of the specific processes and factors influencing engagement with GD. These results help identify areas where more education and support is needed and provide direction to genetic professionals supporting their clients as they confront issues of GD and genetic testing.     

At-risk persons' attitudes toward presymptomatic and prenatal testing of Huntington disease in Michigan

One hundred fifty-five individuals at 50% risk of inheriting Huntington disease (HD) were given a questionnaire surveying their sociodemographic characteristics, experience with HD, and attitudes toward presymptomatic and prenatal testing in HD. About two-thirds (63.2%) of the persons indicated they would take a presymptomatic test even if no specific treatment was available. Although one-half (49%) of the respondents stated they would make use of a prenatal test, only 43% of these individuals would decide to terminate a heterozygous fetus. Presymptomatic test results indicating carrier status would influence some of the respondents' decisions about marriage and childbearing. This strong interest of at-risk persons to make use of both presymptomatic and prenatal diagnosis in HD indicates the need for well-organized testing programs. These programs must be designed to address the genetic, psychosocial, and ethical issues that may arise in the use of this type of genetic test.     

Impact of genetic testing for Huntington disease on the family system

The psychological impact of DNA predictive testing on asymptomatic individuals at risk for Huntington disease (HD) has received considerable attention since the advent of the procedure in 1993. This study examined the impact of such testing on families from the families' perspective. Individuals asymptomatic at the time of testing, together with their families, were interviewed in their homes with a semi-structured interview. Eighteen families with a total of 55 individuals participated. Defining the family as the unit of analysis was consistent with Systems Theory that links interactions of individuals, families, and the social environment. Areas of affected family functioning noted by the respondents included: 1) family membership; 2) family patterns of communication; and 3) future care giving concerns as they influenced current relationships. Eighty-one percent of families experienced changes in family membership. Members in 50% of families experienced changes in patterns of communication, and 56% percent of persons reported changes in current relationships in response to test results and their implications for future caregiving. The data support the conclusion that genetic testing is a family, as opposed to an individual, matter and that family involvement in the decision making process should be strongly encouraged in order to help families adjust. The data imply that families will benefit in pre-test sessions from an examination of their patterns of dealing with illness issues, both past and present.     

Managing genetic discrimination: strategies used by individuals found to have the Huntington disease mutation

The introduction of predictive testing for Huntington disease (HD) over 20 years ago has led to the advent of a new group of individuals found to have the HD mutation that are currently asymptomatic, yet destined in all likelihood to become affected at some point in the future. Genetic discrimination, a social risk associated with predictive testing, is the differential treatment of individuals based on genotypic difference rather than physical characteristics. While evidence for genetic discrimination exists, little is known about how individuals found to have the HD mutation cope with the potential for or experiences of genetic discrimination. The purpose of this study was to explore how individuals found to have the HD mutation manage the risk and experience of genetic discrimination. Semi-structured individual interviews were conducted with 37 individuals who were found to have the HD mutation and analysed using grounded theory methods. The findings suggest four main strategies: "keeping low", minimizing, pre-empting and confronting genetic discrimination. Strategies varied depending on individuals' level of engagement with genetic discrimination and the nature of the experience (actual experience of genetic discrimination or concern for its potential). This exploratory framework may explain the variation in approaches and reactions to genetic discrimination among individuals living with an increased risk for HD and may offer insight for persons at risk for other late-onset genetic diseases to cope with genetic discrimination.     

Predictive testing for Huntington''s disease: after the gene. The United Kingdom Huntington''s Disease Prediction Consortium.

The discovery of a mutation responsible for Huntington's disease (HD) offers the possibility of accurate predictive testing, as well as hope for treatment or prevention of this disease. We urge caution in the use of this new test as considerable ethical and counselling problems still exist, and new issues have arisen. The current guidelines for predictive testing should still apply, since it remains vital that subjects and their families have time to come to terms with the diagnosis of HD, and the implications of testing. Mutation analysis may allow the diagnosis of HD in isolated cases, or reverse a test result produced using linkage. Problems will arise as those at 25% risk may now receive a result despite the lack of support of their parent at 50% risk who may not wish to have their own status defined. In addition, couples who seek the exclusion test in pregnancy may find it difficult to investigate the pregnancy without producing information on themselves. Different centres should cooperate in maintaining the confidentiality of family members, ensuring that adequate counselling is given before results are produced which may affect the wider family.     

To know or not to know: a review of behaviour and suicidal ideation in preclinical Huntington's disease

OBJECTIVE: At present, the problems associated with suicidal ideation and suicide in Huntington's disease (HD), worldwide, are much the same as 2 decades ago. This study seeks to investigate the psychological complications of predictive testing in HD at risk populations. METHODS: The key problems of predictive testing, fear of acquiring carrier status, psychological consequences, autonomy, and rights to know are discussed. RESULTS: This review (1) describes psychological affect and problems of persons facing the decision to test for HD, (2) discusses suicidal ideation, behaviour, and catastrophic events associated with predictive testing, (3) assesses ethical questions raised in the genetic counselling, (4) questions whether counsellors should promote or advocate predictive testing, and finally (5) discusses what professionalism actually is in genetic counselling. CONCLUSION: The need for professional counselling, using a well designed protocol, and the importance of focusing on the suicide risk of participants in predictive testing programs are emphasized. PRACTICE IMPLICATIONS: The counsellor has an obligation to provide adequate information. The professionals should not promote nor advocate presymptomatic DNA-testing. Depression, hopelessness, anxiety, emotional distress, suicidal tendencies, and social dysfunction grading should be considered in predictive testing of HD.     

Attitudes toward presymptomatic testing in Huntington disease

One hundred thirty-one individuals at 50% risk of inheriting Huntington disease (HD) responded to a survey to study their attitudes toward taking a genetic test based on the identification of a genetically linked DNA polymorphism. Ninety-six percent of the respondents believe that presymptomatic testing should be available, and 66% say they will use it themselves. Fewer married individuals, in comparison to those single, separated, and divorced, intend to take the test. Many respondents (40%) said their primary reason for wanting to be tested is to end the uncertainty in their lives. Results suggest that there will be self-selection in test use, with many individuals who believe they will be depressed or possibly suicidal with a positive test result deciding not to be tested or unsure about testing. However, 15% of those who want to be tested acknowledge that they may be at risk for suicide if they are probable gene carriers. Only 12% of all respondents say they will be likely to use prenatal testing, suggesting that initial demand may be low in New England. Implementation of presymptomatic testing challenges health care providers to develop strategies to care for otherwise healthy persons who will be given a diagnosis years before the onset of illness.     

Experience over fifteen years with a protocol for predictive testing for Huntington disease

ObjectiveTo compile a comprehensive profile of the participants who had predictive testing from Huntington disease (HD) between 1994 and 2008 in Montreal, Canada.MethodThis is a retrospective cohort study. The predictive testing protocol consisted of a telephone interview to give information about predictive testing and collect demographic data; a psychological assessment and counseling session; a session focused on medical and family history of HD; a session reserved for genetic counseling; a session where results were given to participants; and a follow-up telephone interview.ResultsA total of 181 applicants requested presymptomatic testing. 135 applicants (77 women and 58 men) completed the protocol and received test results while 40 withdrew. Of the latter, 3 manifested symptoms of the disease and were referred to a neurologist or psychiatrist, and 3 had previously been tested by linkage analysis. Participants usually mentioned more than one reason for requesting predictive testing but the most frequent was to put an end to uncertainty concerning their risk of illness. The proportion of positive and negatives test results was 40% and 54.1% respectively, significantly different from the expected 50% (p < 0.01). Prenatal testing was not frequently requested.ConclusionAll the participants expressed satisfaction regarding their decision to be tested. None to our knowledge had a catastrophic reaction (major depressive disorder or psychiatric hospitalization, declared suicide attempt or suicide). Our study highlights that preparation for receiving test results is a psychologically complex process for which appropriate support in a timely fashion is critical. We feel that a cautious and ethical case by case approach remains essential and that high standards of testing should be maintained because of the far reaching impact of test results.