Predictive testing for Huntington disease: I. Description of a pilot project in British Columbia

Psychiatric and Psychosocial Characteristics of a Cohort of Spanish Individuals Attending Genetic Counseling Due to Risk for Genetically Conditioned Dementia

Background:

Predictive genetic tests are presently effective over several medical conditions, increasing the demand among patients and healthy individuals. Considering the psychological burden suspected familial dementia may carry on individuals, assessing personality, coping strategies, and mental health could aid clinicians in findings the appropriate time for delivering genetic test results and predict compliance regarding genetic counseling and expectations towards the genetic condition depending on the outcome.

Objective:

To describe the psychiatric, psychological, and coping characteristics of a sample of Spanish individuals at risk of familial dementia before genetic test results were given.

Methods:

We included 54 first degree relatives of patients diagnosed with Alzheimer’s disease, lobar frontotemporal degeneration, or prion diseases. The NEO-FFI-R, COPE, and HADS tests evaluated personality, coping strategies, and psychological distress, respectively.

Results:

Anxiety and depression were below the cut-off point for mild severity. Conscientiousness and Agreeableness were the most preponderant personality factors, while Neuroticism was the least. Positive reinterpretation and Acceptance were the most frequent coping strategies, and Denial and Alcohol and drug use were the least used. Ongoing medical pathologies increased depression, while psychiatric disorders worsened psychological distress.

Conclusion:

Contrary to our expectations, PICOGEN candidates showed psychological distress and personality traits within normative ranges, and the use of problem-focused coping strategies prevailed over avoidance coping strategies. Nevertheless, clinicians should pay particular attention to individuals attending genetic counseling who are women, aged, and present an ongoing psychiatric disorder and psychiatric history at inclusion to ensure their mental health and adherence throughout the process.

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.

The psychological impact of predictive genetic testing for Huntington's disease: a systematic review of the literature

Huntington's disease (HD) is a neurodegenerative genetic condition for which a predictive genetic test by mutation analysis has been available since 1993. However, whilst revealing the future presence of the disease, testing may have an adverse psychological impact given that the disease is progressive, incurable and ultimately fatal. This review seeks to systematically explore the psychological impact of genetic testing for individuals undergoing pre-symptomatic mutation analysis. Three databases (Medline, PsycInfo and Scopus) were interrogated for studies utilising standardised measures to assess psychological impact following predictive genetic testing for HD. From 100 papers initially identified, eight articles were eligible for inclusion. Psychological impact of predictive genetic testing was not found to be associated with test result. No detrimental effect of predictive genetic testing on non-carriers was found, although the process was not found to be psychologically neutral. Fluctuation in levels of distress was found over time for carriers and non-carriers alike. Methodological weaknesses of published literature were identified, notably the needs of individuals not requesting genetic testing, as well as inadequate support for individuals registering elevated distress and declining post-test follow-up. Further assessment of these vulnerable individuals is warranted to establish the extent and type of future psychological support.

Hunting human disease genes: lessons from the past, challenges for the future

The concept that a specific alteration in an individual’s DNA can result in disease is central to our notion of molecular medicine. The molecular basis of more than 3,500 Mendelian disorders has now been identified. In contrast, the identification of genes for common disease has been much more challenging. We discuss historical and contemporary approaches to disease gene identification, focusing on novel opportunities such as the use of population extremes and the identification of rare variants. While our ability to sequence DNA has advanced dramatically, assigning function to a given sequence change remains a major challenge, highlighting the need for both bioinformatics and functional approaches to appropriately interpret these data. We review progress in mapping and identifying human disease genes and discuss future challenges and opportunities for the field.

A review of the inherited ataxias: recent advances in genetic, clinical and neuropathologic aspects

Inherited ataxias are a heterogeneous group of disorders characterized by autosomal dominant and recessive inheritance. Recent advances in genetic research have resulted in an improved comprehension of their clinical presentation. Autosomal dominant cerebellar ataxias (ADCAs) include spinocerebellar ataxias (SCAs) and dentatorubral-pallidoluysian atrophy (DRPLA); six of these have been found to be trinucleotide repeat disorders. Episodic ataxia, types 1 and 2, are at present recognized to be channelopathies, caused by point mutations. Friedreich's ataxia (FA) which is an autosomal recessive disorder, resulting from a a unique trinucleotide repeat, is now recognized to have a wide age of onset and clinical spectrum. Ataxia-telangiectasia (AT), also an autosomal recessive cerebellar ataxia, is characterized by immunodeficiency. In this article, the genetic and clinical characteristics of these diseases are reviewed in detail.

A grand challenge: providing benefits of clinical genetics to those in need

Genetic research, techniques, and knowledge have rapidly expanded in the last two decades with the completion of the Human Genome Project and other major advances in discovery research and diagnostic technologies. Although these developments have obvious potential, they also raise significant challenges related to programs for the actual delivery of useful genetic testing and services. This challenge is particularly acute in rural and remote areas, where lack of access to genetic services is pervasive resulting in significant inequities in access and availability of services. Huntington disease, the classic example of an adult-onset hereditary disorder, is used to illustrate this concern and highlight the imperative of exploring novel mechanisms to improve access to effective genetic services. The components of an effective and practical solution strategy are outlined, including the development of innovative delivery systems such as telemedicine, web-based education tools, and cost-reduction mechanisms. A proactive approach is essential to ensure the potential benefits, and availability of clinical genetics is realized by those in need rather than just those in reach.

Genetic counseling for frontotemporal dementias

Frontotemporal dementia (FTD) is an umbrella term for a heterogeneous group of neurodegenerative disorders that are characterized by changes in cognition, language, personality, and social functioning. Approximately 40% of individuals with FTD have a family history of dementia, but less than 10% have a clear autosomal dominant pattern of inheritance. However, establishing a clear mode of inheritance in FTD is complicated by clinical heterogeneity, variable expression, phenocopies, misdiagnosis, early death due to other causes, missing medical records, and lost family histories. Mutations in the microtubule-associated protein tau and progranulin genes have been reported in the majority of hereditary cases, making genetic testing of at-risk individuals possible. The first step in counseling a family with a history of FTD is to take a comprehensive family history with confirmation of any diagnosis in a family member with medical records to the extent possible. If the pedigree analysis suggests an autosomal dominant pattern of inheritance, genetic testing of an affected relative may be offered to the family to determine if a mutation is present. If a mutation is found, relatives interested in pursuing genetic testing should be referred to a genetic counselor familiar with genetic testing for neurodegenerative disorders. Predictive testing of unaffected and at-risk relatives should only be offered in the context of a comprehensive genetic counseling protocol offering pre- and post-test counseling and support. One survey of at-risk individuals in a large family with FTD found that 50% were interested in testing. In one study actually offering genetic testing for FTD, the rate of uptake of testing was only 8.4%. A more recent study estimated the uptake for testing for FTD to be somewhere between 7% and 17% and attributed the low uptake to family resistance to testing. While genetic testing may be appropriate for some families with Alzheimer's disease and FTD, uptake of testing may be expected to be low.

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.

Depression and Suicidal Ideation After Predictive Testing for Huntington's Disease: A Two-Year Follow-up Study

The present study reports a two-year follow-up of psychological effects of predictive testing for Huntington's disease. Questionnaires assessing depression, general health, well-being, self injurious behavior, life satisfaction, and lifestyle were completed by 35 carriers and 58 non-carriers before the predictive test, and 2, 6, 12, and 24 months afterwards. Both carriers and non-carriers showed high suicidal ideation before the predictive testing. Depression scores and frequency of suicidal thoughts increased for carriers, compared to non-carriers, over time. There were no differences regarding life satisfaction or life style between carriers and non-carriers. Predictive testing was beneficial in reducing overall ill-health symptoms and increasing well-being for those initially expressing concern about Huntington's disease. The importance of assessing suicidal ideation and of continuing to provide adequate support is emphasized.

Emotional reactions to predictive testing in Alzheimer's disease and other inherited dementias

This work describes the reasons and emotional responses of healthy descendants after counseling for presenilin mutations in early-onset familial Alzheimer's disease (EOFAD), tau mutations in familial frontotemporal dementia (FTD), and prion mutations in fatal familial insomnia (FFI). A multidisciplinary protocol following Huntington's disease counseling guidelines and a post-test follow-up program were developed to counsel healthy descendants of affected families. The psychological consequences, anxiety levels, and depression status were assessed through validated scales before and after disclosing the information. Nine people from three different families, one with EOFAD, another with FTD, and the other with FFI came for counseling. Their main reason for testing was to initiate early treatment in the future. Disclosing the information decreased anxiety in two carriers, increased it temporarily in one, and had no effect in another. All noncarriers felt relieved. Overall, after a mean of 30 months of follow-up, no negative psychological reactions were observed. All participants positively valued the program. Although preliminary, our observations suggest that predictive testing in EOFAD, FTD, and FFI is safe and may be of benefit when performed with a delicate approach under strict pretest counseling protocols and post-test follow-up programs. The emotional reactions were similar, although the diseases, their phenotype, and mutation characteristics were different.

"You have shown me my end": attitudes toward presymptomatic testing for familial amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a lethal degenerative motor neuron disease. Approximately, 5-10% of cases of ALS are familial (FALS), inherited primarily as an autosomal dominant trait. Recently, mutations in Cu/Zn superoxide dismutase (SOD1) have been identified; 15-20% of familial cases carry this mutation, providing a marker for diagnosis, carrier testing, and prenatal detection. We assessed understanding of genetics of FALS in relatives of patients cared for at the Forbes Norris MDA/ALS Research Center in San Francisco. A total of 25 participants completed a questionnaire and semistructured interview. Of these, 60% would have gene testing for themselves; 36% believed testing of children or adolescents was a good idea. Overall knowledge of genetics of FALS was limited. Also, 24% of respondents understood the inheritance pattern of FALS; 64% were aware that not all individuals who had the gene would show symptoms in their lifetime. Families were confused about whether they would receive results from linkage studies. We recommend that: (1) physicians refer relatives of newly diagnosed individuals for genetic counseling and possibly psychological counseling; (2) investigators ensure that participants comprehend the purpose of gene identification is for research, not disclosure of individual results; (3) families be helped to understand how to keep abreast of medical and genetic advances; (4) following the model of Huntington disease (HD), consensus guidelines for FALS genetic counseling and testing be developed.

Psychosocial impact of predictive testing for myotonic dystrophy type 1

In the Saguenay-Lac-Saint-Jean region (Quebec, Canada), a predictive DNA-testing program for myotonic dystrophy type 1 (DM1) has been available as a clinical service since 1988. From 1 to 12 years (median, 5 years) after receiving predictive testing, a total of 308 participants (44 carriers and 264 non-carriers) answered a questionnaire to determine the psychosocial impact of this genetic testing. The main reasons for wanting to be tested were to learn if children are at risk for DM1 or for reproductive decision making (75%) and to relieve the uncertainty for themselves (17%). The majority of participants (96.1%) remembered correctly their test result. At the time of the survey, the perception of the general well-being, the psychological distress (Psychiatric Symptom Index), and the self-esteem (Rosenberg Self-Esteem Scale) were similar in carriers, in non-carriers, and in the reference (Quebec) population. When participants indicated a change in different aspects of their lives following predictive testing, it was perceived as a change for the better by non-carriers and as a change for the worse by carriers. Nevertheless, for a majority of carriers and of non-carriers, the test result did not bring changes in their lives. All respondents believed that predictive testing should be available for the at-risk population and the vast majority of carrier and of non-carriers would recommend the use of predictive testing to their family members. Predictive testing for individuals at-risk of DM1 can be offered safely within a well-organized clinical and genetic counseling program that includes careful pre-test counseling, pre-test clinical assessment, post-test psychological support, and follow-up for those identified as carriers.

?The Lion, the Witch and the Wardrobe?: Impact on sibs of individuals with AAT deficiency

Alpha(1)-antitrypsin (AAT) deficiency is a genetic disorder that may cause serious pulmonary or liver impairment in children or adults. Although genetic sequencing of the AAT gene has only been available for 20 years, analysis of the amount and electrophoretic mobility of the AAT protein has allowed clinical phenotyping for more than 40 years. There have been no studies assessing the psychological impact of having a sib affected by AAT deficiency. Twenty-five participants drawn from the Alpha-1 Research Registry completed a questionnaire and semi-structured interview. Respondents were supportive of testing prior to adulthood for AAT status; 18 thought it was a good idea to test a child, three did not know, and four said children should not be tested, primarily citing insurance concerns. Of those 18 who stated it was a good idea, 14 would test at birth. Knowledge of genetics of AAT deficiency was limited; only 44% of respondents understood the inheritance pattern. We recommend: (1) parents and sibs need help in mourning the loss of children with AAT deficiency; young sibs are at risk for trauma and long-term developmental problems. (2) Teams evaluating donors for liver transplantation should be aggressive in ruling out AAT deficiency prior to invasive testing. (3) Testing should be offered to individuals with a family history of AAT deficiency to obtain the health benefits of lifestyle modification and limit the burden of disease discovery in symptomatic relatives. (4) Awareness of liver disease from AAT deficiency should be increased.

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.

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.

Predictive Testing for Huntington's Disease: How Does it Impact on Cognitive Performance?

The discovery of a polymorphic DNA marker for Huntington's Disease (HD) in 1983, and the specific gene responsible in 1993, led to predictive testing programmes out of which came research into whether or not cognitive impairment was present presymptomatically in those at risk for HD. The results of these studies have been conflicting and inconclusive. Methodoiogical limitations have probably contributed to the differing findings. The present study attempted to expand upon previous studies by analysing the data in a more comprehensive manner, and with additional control conditions. In this study, 26 individuals, at risk but presymptomatic, for HD were recruited from the Johannesburg Predictive Testing Programme and administered a battery of psychological tests prior to molecular analysis. Of this HD group, 11 were subsequently positive for the gene (the HD+ group) and 15 were negative (HD- group). A carefully chosen control group, (matched for age, sex, and education - Control Group 1) and a group of individuals experiencing a life threatening medical illness (without CNS involvement - Control Group 2) were administered the same battery of psychological tests. Four-way Analysis of Variance between the HD+, HD-, and Control groups was conducted to detect specific differences between the groups. The results indicated that the HD+ group showed mild impairment for declarative memory function. However, it would appear that undergoing the psychological evaluation itself impacted upon the test performance of both the HD+ and HD- groups.

Beyond consent: ethical and social issues in genetic testing

Informed consent is a vital ethical doctrine in clinical medicine and, through genetic counselling, is being applied to genetic testing. But genetic testing raises issues that transcend the traditional concept of informed consent. Genetic tests are adopted without demonstrable clinical benefit, and the consequences of testing can reach beyond the individual to their families and communities. Understanding the social and cultural context of genetic testing will lead to more informed discussion and debate on these issues.

Never again joy without sorrow: the effect on parents of a child with ataxia-telangiectasia

The purpose of this study was to explore the impact of having a child with ataxia-telangiectasia (A-T) as well as to assess parental understanding of the genetics of A-T and attitudes toward carrier testing. Sixty-eight parents of individuals with A-T were interviewed. Ninety percent of the parents correctly believed if there is a child with A-T, both are obligate heterozygotes. Only 9% knew each well sib had a two-thirds chance of being a carrier. Eighty-four percent would have their unaffected child tested for carrier status prior to age 18 years. Eighty-two percent believed heterozygosity is associated with increased health risks. We offer the following recommendations. 1) Physicians must realize that communicating the possibility of early death is difficult; parents need guidelines so they know what to expect, but diagnosis should not be a death sentence. Clinicians should stress individual variations in expression of the disorder and offer hope for future progress in treatment. 2) Parents underestimated carrier risks for the well sib and the frequency of carrier status in the general population. Although these distortions are self-protective, they interfere with transmission of accurate genetic information to their children. Parents should be referred to genetic counseling. 3) Psychological counseling should be offered to families at the time of diagnosis so parents can support each other, the affected, and unaffected offspring.

A mark on the arm: myths of carrier status in sibs of individuals with ataxia-telangiectasia

The ATM gene, mutated in ataxia-telangiectasia (A-T), was identified by positional cloning. The discovery of the ATM gene now allows the identification of A-T heterozygotes [Telatar et al., 1998], who may be at increased risk of cancer. The purpose of this study was to (a) identify sib's interest in carrier testing, (b) explore perception of carrier status, and (c) assess levels of understanding of genetics of A-T. This is the sib component of a study of 103 parents and sibs (68 parents and 35 sibs) of individuals with A-T. Thirty-five sibs from 24 families, including 26 adults and 9 adolescents, drawn from the University of California, Los Angeles, the A-T Clinical Center at the Johns Hopkins University School of Medicine, and the A-T Children's Project, were interviewed. Eighty-five percent of adult sibs stated correctly that if a child has A-T, both parents are heterozygotes; 76% knew the A-T gene had been identified. Ninety-two percent would request carrier testing for themselves if available. Seventy-nine percent would want their child tested for carrier status prior to the age of 18. Seventy-three percent believed that being a carrier is associated with increased health risks. Sibs have numerous misconceptions surrounding carrier status and genetics of A-T. Provision of factual information about genetic transmission is necessary, but unfortunately insufficient, to counter deeply held views of self and others. Genetic counseling, which explores the way in which this information is filtered and interpreted, could be an effective tool in dispelling family myths. We conclude that A-T sibs need comprehensive support in relation to carrier testing.

The individual, the family, and genetic testing

Genetics plays a role in every disease, yet few health care providers understand basic genetic principles or the science underlying the genetic testing process. An understanding of the science behind genetic advances is necessary, and it is equally important for health professionals to have an understanding of the complex nature of genetic testing for individuals and their families. Much of the debate about the psychological effects of genetic testing has occurred in the absence of empirical data on diseases for which predictive testing has only recently emerged. This article will review selected literature on genetic testing and its implications for the individual and the family. The responses of families and individuals to the diagnosis of a genetic disease will be reviewed, and Huntington disease will be used as the paradigm for examining issues related to genetic testing for adult-onset cancers. Literature addressing the response to genetic susceptibility for adult-onset cancers and the implications of testing children also will be explored. Finally, identification of emerging issues relevant to genetic screening will provide a framework for identifying needed nursing research in genetic testing for adult-onset cancer risk.

Genetic counseling for BRCA1/BRCA2 testing

Genetic counseling plays a key role in the BRCA1/BRCA2 testing process. The initial genetic counseling encounter will determine the appropriateness of the test by collecting a detailed family history and determining the likelihood that the family has a BRCA1 or BRCA2 mutation. Once the test is offered, then genetic counseling discussions center around the possible test results, implications of the results to the patient and other relatives, and risks and benefits of testing. The goal of this pre-test genetic counseling session is to ensure that patients have sufficient information with which to make a decision about being tested. At results disclosure, individuals can learn their results along with information about cancer risks and medical management options. Follow-up genetic counseling services can provide continued support and help arrange consultations with other medical care providers as needed. All clinical BRCA1/BRCA2 testing programs should include pre- and post-test genetic counseling.

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.

Some psychosocial aspects of nonlethal chondrodysplasias: I. Assessment using a Life-Styles Questionnaire

Studies concerning the psychosocial aspects of skeletal dysplasias that cause disproportionate short stature have been few and have usually involved small numbers of patients. As part of a study involving patients with chondrodysplasias and their families, an assessment battery of standardised instruments designed to measure depression, anxiety, self-esteem, personal support networks, marital adjustment, and family structure were completed by patients and, in many cases, their sibs, spouses, and/or parents. This first in a series of six papers reports the results of a Life-Styles Questionnaire which provides some insights into the levels of satisfaction with various aspects of life, including friendships, employment, the use of some substances and services, and the impact of the skeletal dysplasia on career, marriage, and childbearing. Results are presented for patients and the unaffected parents of patients. Overall, the study has shown a high level of satisfaction with many aspects of life. However, there are important differences in attitudes between the married and unmarried patients, and in some cases the unaffected parents, in a number of areas including health, overall satisfaction with life, and concerns surrounding child bearing and employment.

Reactions to predictive testing in Huntington disease: case reports of coping with a new genetic status

A predictive testing program for Huntington disease has been available in Stockholm, Sweden since October 1990. Psychosocial assessments were performed throughout the testing program to evaluate the impact of the risk situation itself and the effect of predictive testing, and to identify those individuals who were most vulnerable to severe stress and anxiety reactions. All subjects underwent neurological, neuropsychological, and psychiatric examinations. Individuals undergoing predictive testing were assessed twice by a genetic counsellor before receiving their results, and at 10 days (gene carriers only) and then 2, 6, 12, and 24 months after receiving the results. The process of coping with the test results and the psychological adjustment to knowledge about new genetic status have been shown to vary considerably. In this report, we describe the results obtained from two gene carriers and two noncarriers. The four persons chosen represent different ways of coping with the outcome of the test and of integrating knowledge about their genetic status into everyday life. These cases illustrate common themes and recurrent problems often surfacing during the counselling and testing process. The longitudinal evaluations provide information about the impact, adaptation, and long-term effects of living with a new genetic status.

Risk reversals in predictive testing for Huntington disease

The first predictive testing for Huntington disease (HD) was based on analysis of linked polymorphic DNA markers to estimate the likelihood of inheriting the mutation for HD. Limits to accuracy included recombination between the DNA markers and the mutation, pedigree structure, and whether DNA samples were available from family members. With direct tests for the HD mutation, we have assessed the accuracy of results obtained by linkage approaches when requested to do so by the test individuals. For six such individuals, there was significant disparity between the tests. Three went from a decreased risk to an increased risk, while in another three the risk was decreased. Knowledge of the potential reasons for these changes in results and impact of these risk reversals on both patients and the counseling team can assist in the development of strategies for the prevention and, where necessary, management of a risk reversal in any predictive testing program.

Psychological aspects of genetic counselling: a review of the experience with Huntington's disease

Presymptomatic DNA-testing for adult-onset diseases has serious psychological consequences. Here the psychological consequences of presymptomatic DNA-testing for Huntington's disease are reviewed. Both carriers and non-carriers experience emotional reactions after disclosure of their test result. However, up to today no long-term adverse emotional consequences have been revealed. Future research on other adult-onset genetic diseases should provide information about the reactions of children. In genetic counselling, attention should be paid to the reactions of people with a decreased risk. Genetic counselling must focus on the whole family and not on the individual applicant.

Developmental tasks of childhood and adolescence: implications for genetic testing

Many reports have recently recommended a careful weighing of the potential benefits and harms of genetic testing (carrier or predisposition) of children and adolescents [Andrews et al., Washington DC: National Academy Press, 1994; Wertz et al., JAMA, 272:875-881, 1994; Clinical Genetics Society (UK), J Med Genet, 31:785-797, 1994; ASHJ/ACMG, Am J Hum Genet, 57:1233-1241, 1995]. Despite this, youngsters are currently being tested for late-onset disorders as well as for carrier status [Reilly and Wertz, Am J Hum Genet, 57:A57, 1995]. Many children to be tested will be those in at-risk families, who may already have experienced the chronic illness or death of a close relative. Thus, reactions to testing will be influenced by prior family experiences. Emotional reactions to testing will be determined by both the child's cognitive and psychosocial development. Testing of adolescents may alter the achievement of developmental tasks, including seeking freedom from parental figures, establishment of personal identity, handling of sexual energies, and remodeling of former idealizations of self and others. There are many potential dilemmas in deciding whether to test a child or adolescent for genetic status. If parents choose not to test, the risk is for later difficulty integrating such information into the self concept. If parents test and do not tell results, the risk is for creating a climate of family secrecy. If parents test and tell results, the risk is robbing the child of the autonomy of his or her own later decision. Perhaps the question of whether to test is not the real question. More than genetic testing, genetic counseling is of crucial importance in thoughtful decisions concerning whether to test an individual child or adolescent. A more important question may be how to provide unaffected children in at-risk families with appropriate counseling. Provision of psychosocial support to at-risk families will enable the child to encounter genetic testing, if necessary, supported with the best possible resources.

Issues in genetic testing for susceptibility to alcoholism: lessons from Alzheimer's disease and Huntington's disease

Evidence from family, twin, and adoption studies suggest a heritable basis for alcoholism. However, alcoholism is likely to be genetically heterogeneous, and any genetic connection is likely to be in the form of genes conferring an increased risk or susceptibility. In this study, we present the evidence for a genetic component for alcoholism, and examine the precedent for genetic testing and screening for genetic susceptibility using Huntington's disease and Alzheimer's disease as examples. Finally, we discuss the preparations that need to be made before taking any findings about the genetics of alcoholism from the research laboratory into the clinic.

Huntington's disease predictive testing: the case for an assessment approach to requests from adolescents

Adolescents who are actively requesting Huntington's predictive testing of their own accord pose a dilemma to those providing testing. In the absence of empirical evidence as regards the impact of genetic testing on minors, current policy and guidelines, based on the ethical principles of non-maleficence and respect for individual autonomy and confidentiality, generally exclude the testing of minors. It is argued that adherence to an age based exclusion criterion in Huntington's disease predictive testing protocols is out of step with trends in UK case law concerning minors' consent to medical treatment. Furthermore, contributions from developmental psychology and research into adolescents' decision making competence suggest that adolescents can make informed choices about their health and personal lives. Criteria for developing an assessment approach to such requests are put forward and the implications of a case by case evaluation of competence to consent in terms of clinicians' tolerance for uncertainty are discussed.

Adverse psychological events occurring in the first year after predictive testing for Huntington's disease. The Canadian Collaborative Study Predictive Testing

A total of 135 participants in the Canadian predictive testing programme for HD were followed for at least one year in one of four study groups: increased risk (n = 37), decreased risk ( n = 58), uninformative (n = 17), or not tested (n = 23). Clinical criteria for an adverse event were a suicide attempt or formulation of a suicide attempt plan, psychiatric hospitalisation, depression lasting longer than two months, a marked increase in substance abuse, and the breakdown of important relationships. Quantitative criteria, as measured by changes on the General Severity Index of the Symptom Checklist 90-R and the Beck Depression Inventory, were also used to identify people who had adverse events. Twenty of the 135 participants (14.8%) had an adverse event. There were no significant differences between those with or without an adverse event with respect to age, sex, marital status, education, psychiatric history, general psychiatric distress, or social supports at baseline. However, evidence for depression was associated with an increased frequency of adverse events (p < 0.04). The adverse events were similar and seen with equivalent frequency in those receiving an increased risk or decreased risk and persons at risk who did not receive a modification of risk. However, a significant difference was found in the timing of adverse events for the increased and decreased risk groups (p < 0.0002). In the increased risk group all of the adverse events occurred within 10 days after results whereas, in the decreased risk group, all of the adverse events occurred six months or later after reviewing test results. These results suggest that people entering into predictive testing with some evidence of clinical depression warrant special vigilance and also suggest that counselling and support should be available for all participants in predictive testing irrespective of the direction of test results.

Barriers to carrier testing for adult cystic fibrosis sibs: the importance of not knowing

Early experience in centers offering population screening for cystic fibrosis (CF) has shown that few of the public are taking advantage of the offer [Miller, 1993: New Scientist 139:6]. There is similar low utilization among adult CF sibs [Fanos and Johnson, 1993: Am J Hum Genet 53:A51]. The purpose of this study was to identify factors motivating or interfering with the pursuit of carrier testing in adult CF sibs. Eighty-four adult CF sibs and their spouses, drawn from Children's Hospital, Oakland, CA, and Children's Hospital, Boston, MA, were interviewed for about an hour, and qualitative material was coded on various themes. Structural and psychological barriers to the transmission of genetic information were identified: 1) sibs encountered difficulty in obtaining information concerning availability of testing; 2) parental guilt and blame prevents parents from discussing genetic issues with the sib; 3) sibs rarely discuss testing with each other; 4) the CF patient or parent often has difficulty with the implications of the sib seeking carrier testing; 5) family and individual myths about carrier status influence the sib's decision to seek testing; 6) statistical odds have lost meaning in families where the rare has already occurred; 7) the sib fears loss of interpersonal desirability; and 8) carrier status can serve an important function in binding guilt. Remaining unaware of their carrier status may serve significant psychological functions for individuals at risk.

Are we all of one mind? Clinicians' and patients' opinions regarding the development of a service protocol for predictive testing for Huntington disease. Canadian Collaborative Study for Predictive Testing for Huntington Disease

There are currently different research programs in place to assess the effects of predictive testing for a few late-onset disorders, including Huntington disease (HD) and familial cancers. Prior to providing predictive testing as a service, we sought the views of both the patients and the clinicians as to the importance and value of different items in a research protocol for HD. We mailed questionnaires to 41 clinicians and 351 at-risk patients who had participated in the research protocol, to solicit their opinions on the relative importance of various components of the HD predictive testing research protocol. Completed questionnaires were received from 256 patients (73%) and 33 clinicians (80%). Most participants (96%) were satisfied with the program, and < 3% of persons receiving a modification of risk felt that predictive testing had impaired their quality of life. While there was consensus on the importance of most components of the protocol, significantly more clinicians than patients (97% vs. 72%; P = 0.02) felt it was essential to keep written material about HD as part of a service protocol. More patients than clinicians (83% vs. 27%) considered it essential to have 24-hr contact numbers following disclosure of test results (P < 0.0001). Patients also felt more strongly about the importance of counseling about technical aspects of predictive testing (84% vs. 77%; P < 0.02), and about having a support person attend counselling sessions with the patient (62% vs. 48%; P = 0.04). Nearly 25% of participants indicated that they would not want their general practitioner routinely involved in the predictive testing program. These findings have influenced the development of our service protocol, and they underscore the importance of involving both providers and consumers of predictive testing in the development of a service protocol for genetic testing.

Exploration of the effects of predictive testing for Huntington disease on intimate relationships

The focus in predictive testing for Huntington disease is beginning to shift from individuals at risk to an examination of the effects on other relatives, particularly on spouses and partners. We examine the effects of participating in a predictive testing program for 25 couples. When assessed prior to testing, spouses were significantly more depressed than their at-risk partners. After pretest counseling, 6 (24%) of the couples chose not to pursue testing. At baseline, these 6 couples had significantly higher levels of psychological distress and marital dysfunction than couples who did choose to complete testing. Of the 19 couples completing testing, 5 received an increased risk result and 14 received a decreased risk result. Prior to testing, the partners of individuals who later received an increased risk result exhibited higher levels of marital distress. At 3- and 6-month follow-ups, high-risk couples were significantly more distressed than low-risk couples. These levels of distress improved somewhat at 9 months after testing, but began to climb again at 12 months. Individuals at increased risk were significantly more distressed at all points during follow-up as compared to individuals at low risk. No significant differences were found between the partners of high- and low-risk individuals at 3, 6, 9, and 12 months after disclosure.(ABSTRACT TRUNCATED AT 250 WORDS)

Huntington's disease: recent advances in diagnosis and management

Huntington's Disease (HD) is a progressive degenerative disorder of the central nervous system inherited as an autosomal dominant trait. Clinically, the disorder is characterized by choreoathetosis (with age of onset typically in the late thirties or early forties) and neuropsychiatric disturbance. The striatum is particularly vulnerable to the degenerative disease process, with selective loss of medium spiny neurons and decreased levels of associated neurotransmitters, including substance P. GABA, met-enkephalin and dynorphin. Although the underlying pathophysiology is unknown, recent theories concerning pathogenesis have involved mitochondrial abnormalities and excitotoxin-mediated damage. The gene for HD has recently been discovered and characterized as an unstable CAG trinucleotide repeat sequence on the short arm of chromosome 4 (now known as IT15). The direct test now available for the HD gene has facilitated disease diagnosis, particularly for those with unclear family history or chorea of uncertain origin; presymptomatic testing is also available. Management of affected individuals is unsatisfactory as only symptomatic control is available. However, as the effect of the genetic abnormality may soon be known, specific treatment of the disorder may become available in the near future.

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.

Ethical issues in prenatal testing

Many ethical concerns raised by prenatal testing are based on the use and effects of genetic information in nonclinical contexts. Correct or incorrect beliefs about social uses of genetic information may limit the voluntariness of informed consent to prenatal testing. A qualitative study of persons predictively tested for Huntington's disease illustrates how the social context, in this case the family history of being at risk, affects the interpretation of the genetic information and alters relationships. This constitutes a risk of genetic testing. Prenatal testing also requires ethical analysis based on careful understanding of how social attitudes and nonclinical uses affect voluntariness and potential harm and benefits of testing. Investigators conducting research on prenatal tests share the responsibility to evaluate social attitudes toward at-risk persons, nonclinical uses of genetic information, and the social benefits and harm of such uses.

DNA diagnosis in monogenic diseases

Several routine procedures are available for diagnosis of diseases caused by an alteration in a single gene. These techniques include Southern analysis, the polymerase chain reaction, allele-specific oligonucleotide screening, automated DNA nucleotide sequencing, and linkage analysis. DNA testing procedures can be used for diagnosis of disease, determination of carrier status in affected families, or general screening of the population. Some of the more commonly used techniques and their applications are described in this article.

Presymptomatic testing for Huntington's disease: a world wide survey. The World Federation of Neurology Research Group on Huntington's Disease

World wide data on presymptomatic testing for Huntington's disease using closely linked DNA markers show that 1479 persons at risk received completed test results up to the end of 1991. Testing has been carried out in 19 countries, with at least 88 centres involved, and numbers have levelled off after a peak in 1990. Only 5% of those at risk have been tested in six countries with the longest established programmes. Continued monitoring of international data will be of value in assessing the spread and impact of genetic testing, not only for Huntington's disease, but for other serious genetic disorders of later life.

Presymptomatic DNA testing for Huntington disease: identifying the need for psychological intervention

In the Dutch presymptomatic DNA-testing program for Huntington disease (HD), 29 individuals with increased risk and 44 with decreased risk were followed-up 6 months after test results. A prognostic model was built aimed at identifying individuals at risk for psychological maladjustment, as measured by the Impact of Event Scale, the Beck Hopelessness Scale, the General Health Questionnaire, and the Social Support Questionnaire.

RESULTS

1) The more that applicants suffered from intrusive feelings about HD and tried to avoid HD-related situations, prior to the test, the greater the chance that they will experience this 6 months after the test if they proved to be at increased risk; 2) the more that both individuals with increased risk and those with decreased risk who suffered from the threat of having HD tried to avoid HD-related situations prior to the test and the less satisfied they were with available support, the greater the probability that they will show avoidance behavior after the test; 3) the more pessimistic that individuals with increased risk as well as those with decreased risk were about their future prior to the test, the more they avoided HD-related situations and the more dissatisfied they were about their available support (pretest), the greater the probability that they will become depressive and suicidal. Psychological adjustment was also studied as a function of a) intrusion/denial-avoidance pattern over time and b) healthy mental functioning/future expectancies. Most individuals with increased risk (86%) seem to cope well thus far, although this was based largely on strong psychological defenses and dependent on satisfactory relationships.(ABSTRACT TRUNCATED AT 250 WORDS)

Diagnosis of Huntington disease: a model for the stages of psychological response based on experience of a predictive testing program

Persons diagnosed as affected with Huntington's disease (HD) may have similar stages of psychological response to the clinical presentation of the illness. Here we describe a model of these stages of response based on our experience during a predictive testing program for HD. During the Warning Stage, asymptomatic persons are aware of their risk status for HD and develop defenses which favor adaptation to their genetic risk. In response to the initial signs and symptoms of HD (the Incipient Stage) unconscious working through of this realization occurs while it is still kept out of conscious awareness. When symptoms become obvious such that recognition of disease onset is inevitable (Breakthrough Stage) the possibility of the diagnosis of HD is assimilated. After the delivery of the diagnosis during the Adjustment Stage, short- and long-term adaptive responses to living with HD occur. Recognition of the stage of psychological response of a patient who presents with HD is important prior to delivering a clinical diagnosis. In a significant minority of cases, the psychological readiness lags behind the clinical symptomatology and premature presentation of a diagnosis may result in significant untoward adverse events. Understanding of the stages of response may provide a framework for evaluating the psychological state of the person with HD and determining their readiness to receiving the diagnosis. This model may have relevance to the psychological responses of patients to the diagnosis of other late onset autosomal dominant disorders.

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.