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

Huntington's Disease in Chile: Epidemiological and Genetic Aspects

INTRODUCTION

Huntington's disease (HD) is a neurodegenerative, autosomal dominant disabling condition due to an expansion of the CAG trinucleotide in the HTT gene. Motor, psychiatric, and cognitive disorders characterize it. Chilean reports on HD in the era of molecular diagnosis were wanted.

METHODS

This is a retrospective analysis of a prospective cohort of patients with HD seen at the Center for Movement Disorders (CETRAM) in Chile between 2013 and 2019. Sociodemographic, genotype, and neuropsychiatric features were investigated.

RESULTS

One hundred three probands with HD were identified. The majority (63.1%) were born in the metropolitan region, followed by the VIII and V regions with 8.73% and 7.76%, respectively. When pedigrees were analyzed, ninety unrelated families encompassing 1,007 individuals were identified; among relatives, other 35 manifested HD, and 106 died of HD. Besides, five hundred seventy-nine individuals were at genetic risk. The minimum estimated prevalence of HD in Chile in 2019 was 0.72 × 100,000 inhabitants. The mean CAG repeats (CAGR) of 47.2 ± 10.74 for the expanded allele and 17.93 ± 2.05 for the normal allele. The mean age of onset was 41.39 ± 13.47 years. Juvenile cases represented 7.8% of this cohort, and 4.9% had a late onset. There was a negative correlation between the age of onset and the CAGR of the expanded allele (r =-0.84 p < 0.0001). Besides, 79.6% had a family history of HD.

CONCLUSIONS

This is the first report characterizing genetics, motor, and neuropsychiatric features in patients with HD in Chile. The mean length of CAGR expansion of the abnormal allele was similar to previous reports in North America (i.e., Mexico and Canada) and higher than that reported in the neighboring country of Argentina. According to previous estimations, the minimal prevalence of HD in Chile may be lower than expected.

The effect of co-payments on the take-up of prenatal tests

Noninvasive prenatal screening tests help identify genetic disorders in a fetus, but their take-up remains low in several countries. Using a regression discontinuity design, we test the causal effect of a policy that eliminated co-payments for noninvasive screening tests in Italy. We identify the treatment effects by a discontinuity in women's eligibility for a free test based on their conception date. We find that the policy increases the probability of women's undergoing noninvasive screening tests by 5.5 percentage points, and the effect varies by socioeconomic status. We do not find evidence of substitution effects with more expensive and riskier invasive diagnostic tests. In addition, the increase in take-up does not affect pregnancy termination or newborn health. We find some evidence of positive effects on mothers' health behaviors during pregnancy as measured by reductions in mothers' weight gain and hospital admissions during pregnancy, but these are statistically significant only at the 10 percent level.

Spinocerebellar Ataxia Patient Perceptions Regarding Reproductive Options

Background

In vitro fertilization with preimplantation genetic testing is a growing reproductive option for people who want to avoid passing a single-gene condition on to their offspring. The spinocerebellar ataxias are a group of rare, autosomal-dominant neurodegenerative disorders which are strong candidates for the use of this technology.

Objectives

This study aimed to assess knowledge of genetic risk and perceptions of reproductive options in individuals with a diagnosis of spinocerebellar ataxia.

Methods

We administered an online survey to U.S. residents of reproductive age who have been clinically or genetically diagnosed with spinocerebellar ataxia. We assessed their understanding of inheritance and their reproductive opinions.

Results

Of 94 participants, 70.2% answered all four inheritance questions correctly. The majority felt they could describe each reproductive option except prenatal diagnosis. Individuals were most interested in in vitro fertilization with preimplantation genetic testing: 48.4% (45 of 93) said they would consider it. They were least interested in prenatal diagnosis and donated embryos or gametes. Having spinocerebellar ataxia with anticipation and choosing inheritance risk as an important factor were both significantly associated with interest in preimplantation genetic testing. Choosing religion/morality as an important factor was associated with less interest in preimplantation genetic testing and prenatal diagnosis.

Conclusions

Our population displayed basic knowledge of inheritance risk, and the majority wanted to avoid having affected children. Consistent with literature for other autosomal-dominant adult-onset conditions, individuals showed a preference for preimplantation genetic testing. Health care providers should continue to educate patients about reproductive options and their risks and limitations.

Rethinking the "open future" argument against predictive genetic testing of children

Professional consensus has traditionally discouraged predictive genetic testing when no childhood interventions can reduce future morbidity or mortality. However, advances in genome sequencing and accumulating evidence that children and families cope adequately with predictive genetic information have weakened this consensus. The primary argument remaining against testing appeals to children's "right to an open future." It claims that the autonomy of the future adult is violated when others make an irreversible choice to obtain or disclose predictive genetic information during childhood. We evaluate this argument and conclude that children's interest in an open future should not be understood as a right. Rather an open future is one significant interest to weigh against other important interests when evaluating decisions. Thus, predictive genetic testing is ethically permissible in principle, as long as the interests promoted outweigh potential harms. We conclude by offering an expanded model of children's interests that might be considered in such circumstances, and present two case analyses to illustrate how this framework better guides decisions about predictive genetic testing in pediatrics.

Predictive testing for Huntington disease over 24 years: Evolution of the profile of the participants and analysis of symptoms

BACKGROUND

Huntington disease (HD) is a devastating neurodegenerative autosomal dominant genetic condition. Predictive testing (PT) is available through a defined protocol for at-risk individuals. We analyzed the over-24-years evolution of practices regarding PT for HD in a single center.

METHODS

We gathered data from the files of all individuals seeking PT for HD in Lyon, France, from 1994 to 2017.

RESULTS

448 out of 567 participants had exploitable data. Age at consultation dichotomized over 24 years toward an eightfold increase in individuals aged >55 (2/94 vs. 30/183; 2% to 16%; p < .0001) and twice as many individuals aged 18-20 (3/94 vs. 12/183; 3%-7%; p < .05). Motives for testing remained stable. The rate of withdrawal doubled over 24 years (9/94 vs. 38/183; 9%-21%; p < .02). Independently of the time period, less withdrawal was observed for married, accompanied, at 50% risk, and symptomatic individuals, and in those able to explicit the motives for testing or taking the test to inform their children. We also assessed the consistency between the presence of subtle symptoms compatible with HD found before the test by the team's neurologist, and the positivity of the molecular test. The concordance was 100% (17/17) for associated motor and cognitive signs, 87% (27/31) for isolated motor signs, and 70% (7/10) for isolated cognitive signs. Furthermore, 91% (20/22) of individuals who requested testing because they thought they had symptoms, were indeed found carriers.

CONCLUSION

This over-24 years study underlines an increasing withdrawal from protocol and a dichotomization of participants' age. We also show a strong concordance between symptoms perceived by the neurologist or by the patient, and the subsequent positivity of the predictive molecular test.

A case-note review of continued pregnancies found to be at a high risk of Huntington's disease: considerations for clinical practice

Huntington's disease (HD) is a severe neurodegenerative condition that impacts the whole family. Prenatal diagnosis by direct or exclusion testing is available for couples at risk of transmitting HD to their children. An ethical problem can arise after prenatal diagnosis for HD if a known 'high risk' pregnancy is continued to term: international guidelines emphasise that this situation should be avoided where possible, as it removes the resulting child's future right to make an informed, autonomous decision about predictive testing. The UK Huntington's Disease Predictive Testing Consortium recorded 21 pregnancies that were tested, identified as high-risk and then continued. In this qualitative study, health professionals reviewed the case notes of 15 of these pregnancies. This analysis generated guidelines for clinical practice. It is recommended that practitioners: (i) remind couples of the long-term consequences of continuing a high risk pregnancy, (ii) ensure couples understand the information provided, (iii) collaborate closely with other professionals involved in the couple's prenatal care, (iv) prepare couples for the procedural aspects of prenatal diagnosis and a possible termination of pregnancy, (v) allow time for in-depth pre-test counselling, (vi) explain the rationale for only making prenatal diagnosis available subject to conditions, whilst allowing for human ambivalence and acknowledging that these 'conditions' cannot be enforced, (vii) monitor the whole clinical process to ensure that it works 'smoothly', (viii) recommend couples do not disclose the result of the prenatal test to protect the confidentiality and autonomy of the future 'high-risk' child, and (ix) offer on-going contact and support.

Genetic testing for Huntington’s disease: A thematic analysis of online support community messages

Huntington’s disease is a fatal late-onset genetic illness that causes motor, cognitive and psychiatric disorders. Individuals considering genetic testing may benefit from online social support. This study investigates how genetic testing is discussed within health forums. A total of 337 messages written by 58 individuals were analysed using deductive thematic analysis. Discussions examined three themes: deciding to be tested (enquiring about symptoms and starting a new family), preparing for the test (information seeking and attending appointments) and receiving the results (positive and negative results). Forums can reduce the uncertainty of ambiguous symptoms and provide ongoing personalised support before, during and after a genetic test.

27 years of prenatal diagnosis for Huntington disease in the United Kingdom

PURPOSE

There is little long-term, population-based data on uptake of prenatal diagnosis for Huntington disease (HD), a late-onset autosomal dominant neurodegenerative disorder, and the effect of the availability of preimplantation genetic diagnosis (PGD) on families' decisions about conventional prenatal diagnosis is not known. We report trends in prenatal diagnosis and preimplantation diagnosis for HD in the United Kingdom since services commenced.

METHODS

Long-term UK-wide prospective case record-based service evaluation in 23 UK Regional Genetic Centres 1988-2015, and four UK PGD centers 2002-2015.

RESULTS

From 1988 to 2015, 479 prenatal diagnoses were performed in the UK for HD. An exclusion approach was used in 150 (31%). The annual rate of HD prenatal diagnosis has remained around 18 (3.5/million) over 27 years, despite a steady increase in the use of PGD for HD since 2002.

CONCLUSION

Although increasing number of couples are choosing either direct or exclusion PGD to prevent HD in their offspring, both direct and exclusion prenatal diagnosis remain important options in a health system where both PGD and prenatal diagnosis are state funded. At-risk couples should be informed of all options available to them, preferably prepregnancy.

Reverse pre-symptomatic testing for Huntington disease: double disclosure when 25% at-risk children reveal the genetic status to their parent

Predictive testing for Huntington disease (HD) in 25% at-risk individuals is testing with full knowledge, and sometimes assuming, that the parent does not want to know his status. The goal of this study was to understand: (1) the differences in the motivation between 25% and 50% at-risk individuals to be tested and (2) the consequences of "double disclosure", including parental reactions. Test requests from 25% at-risk individuals were rare (155/1611, 10%). We compared their motivation with those of 1456 50% at-risk individuals. The principal motivation to have the test for both groups was "to know" (48% versus 58%, p = 0.049), but the desire to have children was more frequent in the 25% at-risk group (32% versus 17%, p < 0.001). Sixty percent of the 25% at-risk group went through the testing procedure: 15% (n = 14) were variant positive for HD. Testees reported four adverse reactions of their parent (22%): one committed suicide and three became depressed. This result highlights the impact of "double disclosure", a bad result for the person themselves and the transmitting parent. It is the responsibility of the team to anticipate this outcome with the 25% at-risk individuals: children revealing the genetic status to their parent. They should help the testees and their family to find a satisfactory solution to help prevent adverse reactions. This includes ensuring that the candidate is well-infomed abour the testing options and consequences to her/himself but also to her/his parent. The at-risk parent should be offered to discuss the implications of their child's testing.

Genomic information and a person's right not to know: A closer look at variations in hypothetical informational preferences in a German sample

In clinical practice and in research, there is an ongoing debate on how to return incidental and secondary findings of genetic tests to patients and research participants. Previous investigations have found that most of the people most of the time are in favor of full disclosure of results. Yet, the option to reject disclosure, based on the so-called right not to know, can be valuable especially for some vulnerable subgroups of recipients. In the present study we investigated variations in informational preferences in the context of genetic testing in a large and diverse German sample. This survey examined health care professionals, patients, participants of genetic counseling sessions and members of the general population (N = 518). Survey participants were assessed regarding their openness to learning about findings under various hypothetical scenarios, as well as their attitudes about the doctor-patient-relationship in a disclosure situation and about informational transfer to third parties. While the majority of participants wanted to learn about their findings, the extent of support of disclosure varied with features of the hypothetical diagnostic scenarios (e.g., controllability of disease; abstract vs. concrete scenario description) and demographic characteristics of the subjects. For example, subjects with higher levels of education were more selective with regards to the kind of information they want to receive than those with lower levels of education. We discuss implications of these findings for the debate about the right not to know and for the clinical practice of informed consent procedures.

The importance of preventative medicine in conjunction with modern day genetic studies

Genetic screening in the primary care setting is the future of preventative medicine. Genetic testing is an important medical tool for assessing various inheritable diseases, conditions, and cancers. The ability to diagnose patients before symptoms surface can help lessen the severity of symptoms and promote quality of life. However, genetic screening can cause psychological distress from the knowledge of test results, in some cases only serving to increase the risk of developing a condition due to stress. Genetic testing can be conducted anytime in life, even before birth. In this review, a compilation of genetic testing's definitions and boundaries, factors influencing an individual's test outcomes, and an overview of a wide variety of diseases, conditions and cancers were collected.

Ethical issues in neurogenetics

Many neurogenetic conditions are inherited and therefore diagnosis of a patient will have implications for the patient's relatives and can raise ethical issues. Predictive genetic testing offers asymptomatic relatives the opportunity to determine their risk status for a neurogenetic condition, and professional guidelines emphasize patients' autonomy and informed, voluntary decision making. Beneficence and nonmaleficence both need to be considered when making decisions about disclosure and nondisclosure of genetic information and test results. There can be disclosure concerns and challenges in determining whose autonomy to prioritize when a patient makes a genetic testing decision that can reveal the genetic status of a relative (e.g., testing an adult child when the at-risk parent has not been tested). Ethical issues are prominent when genetic testing for neurogenetic conditions is requested prenatally, on minors, adoptees, adult children at 25% risk, and for individuals with psychiatric issues or cognitive impairment. Neurogenetic conditions can result in cognitive decline which can affect decisional capacity and lead to ethical challenges with decision making, informed consent, and determining the patient's ability to comprehend test results. The ethical implications of genetic testing and emerging issues, including direct-to-consumer genetic testing, disclosure of secondary findings from genomic sequencing, and use of apolipoprotein E testing in clinical and research settings, are also discussed. Resources for information about genetic testing practice guidelines, insurance laws, and directories of genetics clinics are included.

Huntington's Disease: Pathological Mechanisms and Therapeutic Strategies

Huntington's disease (HD) is a devastating neurodegenerative disorder that occurs in patients with a mutation in the huntingtin or IT15 gene. Patients are plagued by early cognitive signs, motor deficits, and psychiatric disturbances. Symptoms are attributed to cell death in the striatum and disruption of cortical–striatal circuitry. Mechanisms of cell death are unclear, but processes involving mitochondrial abnormalities, excitotoxicity, and abnormal protein degradation have been implicated. Many factors likely contribute to neuron death and dysfunction, and this has made it difficult to systematically address the pathology in HD. Pharmaceutical therapies are commonly used in patients to treat disease symptoms. These have limited benefit and do not address the inexorable disease progression. Several neuroprotective therapies are being evaluated in animal models of HD as well as in clinical trials. Similarly, cell replacement strategies such as fetal transplantation have been used in the clinic with minimal success, making future cell replacement strategies such as stem cell therapy uncertain. This review describes the disease pathology in HD and addresses many of the past and emerging therapeutic strategies.

1993-2014: two decades of predictive testing for Huntington's disease at the Medical Genetics Unit of the University of Genoa

Background

Predictive testing for Huntington's disease has been available at the Medical Genetics Unit of the University of Genoa from 1987. In 1989, an integrated counseling protocol (geneticist, psychologist, and neurologist) was developed following International Guidelines.

Methods

This is a retrospective analysis of the clinical charts and motivation questionnaires of persons seeking predictive testing through direct DNA analysis from 1993 until 2014, with the aim to evaluate their individual characteristics, motivations, and the outcomes of the counseling protocol.

Results

A total of 299 persons (164 women, 135 men) applied for predictive testing. Most applicants’ features and motivations were similar to those previously described, but surprisingly the percentage of completed protocols was higher among men, 68.5% versus 53.5% (P = 0.011). Likewise, persons over 25 years of age were more likely to take the test than younger applicants (18–25 years): 63.4% versus 48.1% (P = 0.043). In addition, relationship status, having children, and the gender of the affected parent showed different effects on the decision about testing in males and females. No catastrophic reactions were reported during the study period.

Conclusions

We observed that factors influencing the decision‐making process might differ between males and females, and that predictive testing appears a safe procedure if framed within an integrated counseling protocol.

"If It Helps, It's Worth a Try": an Investigation of Perceptions and Attitudes about Genetic Counseling among Southern Manitoba Hutterites

Few studies have explored the public's views of genetic counseling services, and even fewer focus on founder populations with high prevalence of genetic disease, such as Hutterites. The Hutterites are an Anabaptist religious group grounded in a strong Christian faith. The primary aim of this study was to assess Hutterites' views of genetic counseling services. A secondary aim was to compare their views to those obtained in a study of rural Midwestern U.S. residents (Riesgraf et al., Journal of Genetic Counseling, 24(4), 565-579, 2015). One-hundred eleven individuals from southern Manitoba Hutterite colonies completed an anonymous survey assessing familiarity with and attitudes about genetic counseling; perceptions of its purpose, scope and practice; and willingness to use genetic counseling services. Although many respondents were not familiar with genetic counseling, most had accurate perceptions and positive attitudes. For instance, mean ratings showed endorsement of trust in information provided by genetic counselors and agreement that genetic counseling aligns with their values. Logistic regression indicated reported willingness to use genetic counseling services increased if respondents: had a higher self-rated familiarity with genetic counseling; were younger; agreed with the statement: I would trust the information provided by a genetic counselor; and disagreed with the statements: Genetic counseling is only useful for a small group of people with rare diseases, and Genetic counselors help expectant parents choose the eye color of their child. Thematic analysis of comments regarding willingness to use genetic counseling services yielded themes of personal/family risk, pragmatism (genetic counseling is sensible and practical for managing health concerns), and desire to prevent genetic conditions in the Hutterite population. Comparison of the present findings to those of Riesgraf et al. suggests predictors of Hutterites' willingness to use genetic counseling are unique and culturally-based. Limited replication of Riesgraf et al. was achieved. Additional findings, practice implications and research recommendations are presented.

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

Huntington disease (HD) is a late onset ultimately fatal neurodegenerative disorder caused by a cytosine-adenine-guanine ( CAG) triplet repeat expansion in the Huntingtin gene which was discovered in 1993. The PHAROS study is a unique observational study of 1001 individuals at risk for HD who had not been previously tested for HD and who had no plans to do so. In this cohort, 104 (10%) individuals changed their minds and chose to be tested during the course of the study but outside of the study protocol. Baseline behavioral scores, especially apathy, were more strongly associated with later genetic testing than motor and chorea scores, particularly among subjects with expanded CAG repeat length. In the CAG expanded group, those choosing to be tested were older and had more chorea and higher scores on the behavioral section of the unified Huntington's disease rating scale at baseline than those not choosing to be tested. Following genetic testing, 56% of subjects with CAG < 37 had less depression when compared to prior to testing, but depression generally stayed the same or increased for 64% of subjects in the expanded group. This finding suggests that approaches to testing must continue to be cautious, with appropriate medical, psychological and social support.

Homo Ignorans: Deliberately Choosing Not to Know

Western history of thought abounds with claims that knowledge is valued and sought. Yet people often choose not to know. We call the conscious choice not to seek or use knowledge (or information) deliberate ignorance. Using examples from a wide range of domains, we demonstrate that deliberate ignorance has important functions. We systematize types of deliberate ignorance, describe their functions, discuss their normative desirability, and consider how they can be modeled. To date, psychologists have paid relatively little attention to the study of ignorance, let alone the deliberate kind. Yet the desire not to know is no anomaly. It is a choice to seek rather than reduce uncertainty whose reasons require nuanced cognitive and economic theories and whose consequences-for the individual and for society-require analyses of both actor and environment.

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.

Important but not Enough - Information about HD Related Topics and Peer and Professional Support for Young Adults from HD Families

BACKGROUND

The number of people affected by Huntington's disease (HD) is far greater than those with manifest HD because it also includes those at risk, both HD gene mutation carriers and family members not carrying the HD mutation. Many relevant needs of young adults from HD families may not be met at present. This includes advice on important life decisions e.g. family planning and having children, psychological support and treatment of medical conditions.

OBJECTIVE

To survey the opinion of young adults from HD families about relevance and availability of information and support regarding several aspects of HD.

METHODS

An online anonymous questionnaire translated into ten languages contained questions regarding the importance and availability of information and support about HD related topics, and attitudes towards research. Answers were captured in categories or on Likert scales.

RESULTS

Information about HD related topics and the availability of peer and professional support are very important for young adults from HD families. In addition, with the exception of general information about HD, or predictive testing, the vast majority of respondents stated that they did not receive enough information on other important topics, for instance regarding legal advice and they did not feel supported enough by healthcare professionals. HD research was considered to be of high value, though most did not participate in HD research.

CONCLUSION

The results of this survey can help devise a strategy to address these unmet needs and also to facilitate research participation of more young adults from HD families.

Ethical issues in the evaluation of adults with suspected genetic neuromuscular disorders

Genetic testing is rapidly becoming an increasingly significant part of the diagnostic armamentarium of neuromuscular clinicians. Although technically easy to order, the results of such testing, whether positive or negative, have potentially enormous consequences for the individual tested and for family members. As a result, ethical considerations must be in the forefront of the physician's agenda when obtaining genetic testing. Informed consent is an important starting point for discussions between physicians and patients, but the counseling embedded in the informed consent process must be an ongoing part of subsequent interactions, including return of results and follow-up. Patient autonomy, including the right to know and right not-to-know results, must be respected. Considerations of capacity, physician beneficence and nonmaleficence, and privacy all play roles in the process. Muscle Nerve 54: 997-1006, 2016.

22 Years of predictive testing for Huntington's disease: the experience of the UK Huntington's Prediction Consortium

Huntington's disease (HD) is a progressive neurodegenerative condition. At-risk individuals have accessed predictive testing via direct mutation testing since 1993. The UK Huntington's Prediction Consortium has collected anonymised data on UK predictive tests, annually, from 1993 to 2014: 9407 predictive tests were performed across 23 UK centres. Where gender was recorded, 4077 participants were male (44.3%) and 5122 were female (55.7%). The median age of participants was 37 years. The most common reason for predictive testing was to reduce uncertainty (70.5%). Of the 8441 predictive tests on individuals at 50% prior risk, 4629 (54.8%) were reported as mutation negative and 3790 (44.9%) were mutation positive, with 22 (0.3%) in the database being uninterpretable. Using a prevalence figure of 12.3 × 10(-5), the cumulative uptake of predictive testing in the 50% at-risk UK population from 1994 to 2014 was estimated at 17.4% (95% CI: 16.9-18.0%). We present the largest study conducted on predictive testing in HD. Our findings indicate that the vast majority of individuals at risk of HD (>80%) have not undergone predictive testing. Future therapies in HD will likely target presymptomatic individuals; therefore, identifying the at-risk population whose gene status is unknown is of significant public health value.

Predictive genetic testing for neurodegenerative conditions: how should conflicting interests within families be managed?

Predictive genetic testing for a neurodegenerative condition in one individual in a family may have implications for other family members, in that it can reveal their genetic status. Herein a complex clinical case is explored where the testing wish of one family member was in direct conflict to that of another. The son of a person at 50% risk of an autosomal dominant neurodegenerative condition requested testing to reveal his genetic status. The main reason for the request was if he had the familial mutation, he and his partner planned to utilise preimplantation genetic diagnosis to prevent his offspring having the condition. His at-risk parent was clear that if they found out they had the mutation, they would commit suicide. We assess the potential benefits and harms from acceding to or denying such a request and present an approach to balancing competing rights of individuals within families at risk of late-onset genetic conditions, where family members have irreconcilable differences with respect to predictive testing. We argue that while it may not be possible to completely avoid harm in these situations, it is important to consider the magnitude of risks, and make every effort to limit the potential for adverse outcomes.

Prenatal Testing for Adult-Onset Conditions: the Position of the National Society of Genetic Counselors

Advances in genetic testing and the availability of such testing in pregnancy allows prospective parents to test their future child for adult-onset conditions. This ability raises several complex ethical issues. Prospective parents have reproductive rights to obtain information about their fetus. This information may or may not alter pregnancy management. These rights can be in conflict with the rights of the future individual, who will be denied the right to elect or decline testing. This paper highlights the complexity of these issues, details discussions that went into the National Society of Genetic Counselors (NSGC) Public Policy Task Force's development of the Prenatal testing for Adult-Onset Conditions position statement adopted in November 2014, and cites relevant literature on this topic through December 2015. Issues addressed include parental rights and autonomy, rights of the future child, the right not to know, possible adverse effects on childhood and the need for genetic counseling. This paper will serve as a reference to genetic counselors and healthcare professionals when faced with this situation in clinical practice.

Prenatal testing in Huntington disease: after the test, choices recommence

The objective of this study was (1) to determine the impact of prenatal diagnosis (PND) for Huntington disease (HD) on subsequent reproductive choices and family structure; and (2) to assess whether children born after PND were informed of their genetic status. Out of 354 presymptomatic carriers of HD gene mutation, aged 18-45 years, 61 couples requested 101 PNDs. Fifty-four women, 29 female carriers and 25 spouses of male carriers, accepted to be interviewed (0.6-16.3 years after the last PND, median 6.5 years) on their obstetrical history and information given to children born after PND. Women were willing to undergo two or more PNDs with a final success rate of 75%. Reproductive decisions differed depending on the outcome of the first PND. If favourable, 62% couples decided against another pregnancy and 10% chose to have an untested child. If unfavourable, 83% decided for another pregnancy (P<0.01), and the majority (87%) re-entered the PND procedure. In contrast, after a second PND, only 37% asked for a PND and 30% chose to have an untested child. Thirty-three percent had both, tested and untested children. Among children born after PND, 10 years and older, 75% were informed of their genetic status. The decision to prevent transmission of the HD mutation is made anew with each pregnancy. Couples may need more psychological support after PND and pre-counselling sessions should take into account the effect of the outcome of a first PND on subsequent reproductive choices.

Impact of Huntington Disease Gene-Positive Status on Pre-Symptomatic Young Adults and Recommendations for Genetic Counselors

Huntington disease (HD) is an autosomal dominant, progressive neurodegenerative disorder for which there is no cure. Predictive testing for HD is available to asymptomatic at-risk individuals. Approximately half of the population undergoing predictive testing for HD consists of young adults (≤35 years old). Finishing one's education, starting a career, engaging in romantic relationships and becoming a parent are key milestones of young adulthood. We conducted a qualitative study to explore how testing gene-positive for HD influences young adults' attainment of these milestones, and to identify major challenges that pre-symptomatic young adults face to aid the development of targeted genetic counseling. Results of our study demonstrate that 1) knowing one's gene-positive status results in an urgency to reach milestones and positively changes young adults' approach to life; 2) testing positive influences young adults' education and career choices, romantic relationships, and family planning; 3) young adults desire flexible and tailored genetic counseling to address needs and concerns unique to this population. Findings of this study contribute to the understanding of the impact of predictive testing for HD on young adults, and highlight issues unique to this population that call for further research, intervention and advocacy.

Incidental findings of uncertain significance: To know or not to know--that is not the question

BACKGROUND

Although the "right not to know" is well established in international regulations, it has been heavily debated. Ubiquitous results from extended exome and genome analysis have challenged the right not to know. American College of Medical Genetics and Genomics (ACMG) Recommendations urge to inform about incidental findings that pretend to be accurate and actionable. However, ample clinical cases raise the question whether these criteria are met. Many incidental findings are of uncertain significance (IFUS). The eager to feedback information appears to enter the field of IFUS and thereby threaten the right not to know. This makes it imperative to investigate the arguments for and against a right not to know for IFUS.

DISCUSSION

This article investigates how the various arguments for and against a right not to know hold for IFUS. The main investigated arguments are: hypothetical utilitarianism, the right-based argument, the feasibility argument, the value of knowledge argument, the argument from lost significance, the empirical argument, the duty to disclose argument, the avoiding harm argument; the argument from principle, from autonomy, from privacy, as well as the argument from the right to an open future. The analysis shows that both sides in the debate have exaggerated the importance of incidental findings. Opponents of a right not to know have exaggerated the importance of IFUS, while proponents have exaggerated the need to be protected from something that is not knowledge. Hence, to know or not to know is not the question. The question is whether we should be able to stay ignorant of incidental findings of uncertain significance, if we want to. The answer is yes: As long as the information is not accurate and/or actionable: ignorance is bliss. When answering questions that are not asked, we need to think twice.

Analysis of the Reasons for Non-Uptake of Predictive Testing for Huntington's Disease in Spain: A Qualitative Study

Children of persons affected by Huntington's disease (HD) have a 50% chance of inheriting the disease. Genetic testing in Spain is offered to individuals (presymptomatic test) or mothers of fetuses (prenatal) who run the risk of suffering from HD. The objective of this study is to analyze the factors that influence the decisions of adult children of persons affected with HD regarding predictive testing. A qualitative research methodology was used involving 4 focus groups (FGs) made up of adult children of persons with HD in different cities in Spain. The results of the study showed that over half of the focus group participants were inclined to decline genetic testing. The main explanatory determinants for taking or not taking the predictive test are: Maturity of the individual at risk, which was directly related to age; Ability to cope with a positive test result; Experience of living with HD sufferers; Information about testing and psychological support; Attitude of the family; Social visibility of genetic testing; Personality and temperament of each subject at risk of HD. These results imply that these factors should be analyzed in more detail in quantitative studies in order to help the Spanish Department of Health understand why some children of parents with HD decline genetic testing, so that they may and apply these data when creating specific policy regarding this issue.

SCA2 predictive testing in Cuba: challenging concepts and protocol evolution

Spinocerebellar ataxia type 2 (SCA2) is a neurodegenerative disease caused by a CAG repeat expansion in the ATXN2 gene. Cuba has the highest prevalence (6.57 cases/10(5) inhabitants) of SCA2 in the world. The existence of 753 affected individuals and 7173 relatives at risk prompted the development in 2001 of the first predictive testing program in the country. The medical records of over 1193 individuals, who requested the test within a 13-year period, were analyzed retrospectively. The presymptomatic and the prenatal tests had uptake rates of 43.4 and 23.9 %, respectively. Several ethical challenges resulted from this program. These include the following: (1) withdrawal due to the initial protocol's length; (2) the request to participate by 16 at-risk adolescents; (3) the decision made by ten out of 33 couples with a test-positive fetus to carry the pregnancy to term, leading to de facto predictive testing of minors; (4) the elevated frequency of the ATXN2 gene large normal alleles (≥23 to 31 repeats) in the reference population. These issues have led to major changes in the guidelines of the predictive testing protocol: (1) the protocol length was shortened; (2) the inclusion criteria were expanded to reach at-risk adolescents with an interest in prenatal diagnosis; (3) interdisciplinary follow-up was offered to families in which test-positive fetuses were not aborted; (4) prenatal testing was made available to carriers of large normal alleles with ≥27 CAG repeats. The profiles of the participants were similar to those reported for other predictive testing programs for conditions like Huntington disease and familial adenomatous polyposis. The genetic counseling practices at the community level, the ample health education provided to the at-risk population, together with multidisciplinary and specialized attention to the affected families, are lessons from the Cuban experience that can be relevant for other international teams conducting predictive testing for other late-onset neurodegenerative disorders.

Predictive testing for inherited prion disease: report of 22 years experience

The inherited prion diseases (IPD) are a group of untreatable neurodegenerative diseases that segregate as autosomal dominant traits. Mutations in the prion protein gene (PRNP) were first found to be causal of IPD in 1989, before the molecular genetic characterisation of any other neurodegenerative disease. Predictive testing for IPD has subsequently been carried out at a single UK clinical and research centre for 22 years. We have analysed the uptake, consequences and factors influencing the decision for predictive testing over this period. In all, 104 predictive tests were done on individuals at 50% risk, compared with 135 positive diagnostic tests. Using genealogies from clinical records, we estimated that 23% of those at 50% risk have completed testing. There was no gender bias, and unsurprisingly, there was a slight excess of normal results because some patients were already partly through the risk period because of their age. An unexpectedly large number of patients developed symptoms shortly after predictive testing, suggesting that undisclosed early symptoms of disease may prompt some patients to come forward for predictive testing. Fifteen per cent of predictive tests were done >10 years after molecular diagnosis in a proband. A strong determinant of the timing of testing in these patients was a second diagnosis in the family. IPD may generate infectious prions that might be transmitted by surgical procedures; however, we found no evidence that public health information influenced decisions about predictive testing.

Perceptions and Attitudes About Genetic Counseling Among Residents of a Midwestern Rural Area

Relatively few investigations of the public's perceptions and attitudes about genetic counseling exist, and most are limited to individuals at-risk for a specific disease. In this study 203 individuals from a Midwest rural area completed an anonymous survey assessing their familiarity with genetic counseling; perceptions of genetic counseling purpose, scope, and practice; attitudes toward genetic counseling/counselors; and willingness to use genetic counseling services. Although very few respondents were familiar with genetic counseling, most reported accurate perceptions and positive attitudes; mean ratings, however, showed less endorsement of trust in information provided by genetic counselors and less agreement that genetic counseling aligns with their values. Logistic regression indicated reported willingness to use genetic counseling services increased if respondents: had completed some college; rated their familiarity with genetic counseling as high; agreed with the statements: genetic counseling may be useful to someone with cancer in their family, genetic counseling is in line with my values, and genetic counselors advise women to get abortions when there is a problem; and disagreed with the statements: genetic counseling is only useful to a small group of people with rare diseases, and genetic counselors must receive a lot of special training. Additional findings, practice implications, and research recommendations are presented.

Reproductive decision-making among individuals at risk for familial amyotrophic lateral sclerosis

This qualitative study explored the reproductive decision-making process in individuals at 50% risk for familial amyotrophic lateral sclerosis (FALS) from families with a known genetic mutation. We spoke with 10 individuals utilizing a semi-structured interview. Participants had a first-degree relative with FALS, made reproductive decisions in the past 30 years and did not know their genetic status during decision-making. We delineated themes emerging in individuals who chose to have children, those who chose not to have children, and themes describing the process in general. Results showed that those who chose to have children believed that regardless of disease, life is productive. They compared ALS relatively favorably to other diseases, always planned on having children, and hoped for a cure. Individuals who chose not to have children had extensive experience with ALS and caretaking, saw ALS as an inevitable tragedy, and avoided serious relationships. In consultation with partners, individuals considered other reproductive options. Conversations varied in length, and often strengthened relationships. Children experiencing death of a parent was a primary concern. In conclusion, the reproductive decision-making process is complex. Results can guide future research and provide direction for healthcare professionals when discussing the family planning process and prior to predictive genetic testing.

Implementation and utilization of genetic testing in personalized medicine

Clinical genetic testing began over 30 years ago with the availability of mutation detection for sickle cell disease diagnosis. Since then, the field has dramatically transformed to include gene sequencing, high-throughput targeted genotyping, prenatal mutation detection, preimplantation genetic diagnosis, population-based carrier screening, and now genome-wide analyses using microarrays and next-generation sequencing. Despite these significant advances in molecular technologies and testing capabilities, clinical genetics laboratories historically have been centered on mutation detection for Mendelian disorders. However, the ongoing identification of deoxyribonucleic acid (DNA) sequence variants associated with common diseases prompted the availability of testing for personal disease risk estimation, and created commercial opportunities for direct-to-consumer genetic testing companies that assay these variants. This germline genetic risk, in conjunction with other clinical, family, and demographic variables, are the key components of the personalized medicine paradigm, which aims to apply personal genomic and other relevant data into a patient’s clinical assessment to more precisely guide medical management. However, genetic testing for disease risk estimation is an ongoing topic of debate, largely due to inconsistencies in the results, concerns over clinical validity and utility, and the variable mode of delivery when returning genetic results to patients in the absence of traditional counseling. A related class of genetic testing with analogous issues of clinical utility and acceptance is pharmacogenetic testing, which interrogates sequence variants implicated in interindividual drug response variability. Although clinical pharmacogenetic testing has not previously been widely adopted, advances in rapid turnaround time genetic testing technology and the recent implementation of preemptive genotyping programs at selected medical centers suggest that personalized medicine through pharmacogenetics is now a reality. This review aims to summarize the current state of implementing genetic testing for personalized medicine, with an emphasis on clinical pharmacogenetic testing.

Importance of psychiatric examination in predictive genetic testing for Huntington disease

BACKGROUND AND PURPOSE

Huntington disease (HD) is an au-tosomal dominant hereditary neurodegenerative disease with multiplication of CAG triplet in the short arm of chromoso-me 4, manifested by motor symptoms, cognitive dysfunction progressing to dementia, and various types of neuropsychiat-ric disorders. The diagnosis of HD is confirmed by a gene-tic test, which may also be carried out presymptomatically.

MATERIAL AND METHODS

We studied differences in psychiatric examination and psychometric measures among the 52 people at risk of HD, who were recommended to postpone or to continue in the predictive protocol. In addition to the psychiatric examination, we administered the Eysenck Personality Questionnaire (EPQ-A), the Symptom Checklist 90 (SCL-90), and quality of life questionnaire (MANSA).

RESULTS

People at risk of HD with the recommended test postponement showed lower rate of neuroticism and EPQ-A lie score, higher values on the phobia and the so-called 'positive symptom distress index' in SCL-90 and lower quality of life than people at risk of HD with the recommendation to continue.

CONCLUSIONS

Our results indicate that the formalized testing does not bring significant information whereas the clinical psychiatric examination remains the main decisive factor in the recommendation to perform a predictive genetic test. The motivation of applicants is considered as the most important factor in the decision-making process.

Huntington disease: who seeks presymptomatic genetic testing, why and what are the outcomes?

The aims of this study were to: 1) quantify the characteristics of those seeking presymptomatic testing for HD, 2) identify their motivations for testing, 3) quantify the waiting times between the various steps within the testing process, and 4) quantify the outcomes of testing at a large state-wide genetic testing center in Australia. A review of medical charts for all referrals for presymptomatic testing of Huntington disease received over a 4 year period (2006-2010) was undertaken. A total of 152 cases met the study inclusion criteria; the mean age was 39 years, 46 % were male and 61 % underwent genetic testing. Of the males who were tested there was a non-significant trend towards having an affected mother vs father (62 %, p = 0.09), whereas females tested were just as likely to have an affected mother or father. The most frequently cited reasons for seeking testing were "family planning", "plan future", and "need to know". Some 11 % deferred testing following the psychological assessment. Of those at 50 % prior risk, 57.5 % tested positive; this was higher than expected and much higher than reported in other studies. The median times from referral to initial appointment, and then to results was 69 days and 144 days respectively. Overall, this review of medical charts shows the depth of information obtainable from routinely collected data and revealed that a high proportion of patients tested positive for HD at this centre.

Clinical and genetic features of Huntington disease in Sri Lanka

Background

Huntington disease was one of the first neurological hereditary diseases for which genetic testing was made possible as early as 1993. The study describes the clinical and genetic characteristics of patients with Huntington disease in Sri Lanka.

Methods

Data of 35 consecutive patients tested from 2007 to 2012 at the Human Genetics Unit, Faculty of Medicine, University of Colombo was analyzed retrospectively. Clinical data and genetic diagnostic results were reviewed. Statistical analysis was performed using descriptive statistics.

Results

Thirty patients had fully penetrant (FP) CAG repeat mutations and 5 had reduced penetrant (RP) CAG repeat mutations. In the FP group mean ages of onset and diagnosis were 37.5 and 40.4 years, while in the RP group it was 63.0 and 64.8 years respectively. The age of diagnosis ranged from 15 to 72 years, with 2 patients with Juvenile onset (<20 years) and 3 with late onset (>60 years) Huntington disease. The symptoms at diagnosis were predominantly motor (32/35 -91%). Three patients had psychiatric and behavioral disorders. The age difference between onset and genetic diagnosis showed significant delay in females compared to males (p < 0.05). Twenty two (62.8%) had a positive family history, with 13/22 (59.1%) showing a paternal inheritance of the disease. In both groups, those with a family history had a significantly lower age of presentation (p < 0.05). The mean CAG repeat length in patients with FP alleles was 44.6 ± 5 and RP alleles was 37.2 ± 1.1. Age of onset and CAG repeat length of the HTT gene showed significant inverse correlation (p < 0.0005, R² = 0.727).

Conclusions

The clinical and genetic features seen in patients with Huntington disease in the Sri Lankan study population were similar to that previously reported in literature.

Unawareness of motor phenoconversion in Huntington disease

OBJECTIVE

To determine whether Huntington disease (HD) mutation carriers have motor symptoms (complaints) when definite motor onset (motor phenoconversion) is diagnosed and document differences between the groups with and without unawareness of motor signs.

METHODS

We analyzed data from 550 HD mutation carriers participating in the multicenter PREDICT-HD Study followed through the HD prodrome. Data analysis included demographics, the Unified Huntington's Disease Rating Scale (UHDRS) and the Participant HD History of symptoms, self-report of progression, and cognitive, behavioral, and imaging measures. Unawareness was identified when no motor symptoms were self-reported but when definite motor HD was diagnosed.

RESULTS

Of 38 (6.91%) with onset of motor HD, almost half (18/38 = 47.36%) had no motor symptoms despite signs of disease on the UHDRS motor rating and consistent with unawareness. A group with motor symptoms and signs was similar on a range of measures to the unaware group. Those with unawareness of HD signs reported less depression. Patients with symptoms had more striatal atrophy on imaging measures.

CONCLUSIONS

Only half of the patients with newly diagnosed motor HD had motor symptoms. Unaware patients were less likely to be depressed. Self-report of symptoms may be inaccurate in HD at the earliest stage.

Knowledge of and interest in genetic results among Parkinson disease patients and caregivers

The purpose of the study is to investigate Parkinson disease (PD) patients' and caregivers' knowledge of and interest in genetic testing. Gaucher disease (GD) results from recessive mutations in glucocerebrosidase (GBA). Both heterozygote GBA carriers and GD patients are at greater risk for PD. Studies regarding knowledge of and interest in genetic testing have been limited and have not offered genetic results to participants. In this study, 353 PD patients and 180 caregivers were recruited to a PD genetic study. The association between GD, GBA mutations and PD was described to participants who reported their familiarity with genetic terms, answered questions on genetic concepts, and indicated their interest in knowing if they may have GD (two GBA mutations) and other genetic information that could impact their health. Ninety-three-percent of participants were interested in receiving GBA results; however, only 51.6 % of PD participants and 55.6 % of caregivers knew that "scientists have identified genes associated with a higher risk of developing PD." PD patients may benefit from education and genetic counseling on the implications of genetic testing.

Couples at risk for spinocerebellar ataxia type 2: the Cuban prenatal diagnosis experience

Cuba reports the highest worldwide prevalence of spinocerebellar ataxia type 2 (SCA2) and the greatest number of descendants at risk. A protocol for genetic counseling, presymptomatic testing, and prenatal diagnosis of hereditary ataxias has been under development since 2001. Considering that the revision of the experience with prenatal diagnosis for SCA2 in Cuba would enable comparison of ours with international findings, we designed a descriptive study, based on the retrospective revision of the medical records belonging to the 58 couples that requested their inclusion in the program, during an 11-year period (2001-2011). Most of the participants in the prenatal diagnosis program were known presymptomatic carriers, diagnosed through the presymptomatic testing in the same period of study, for an uptake among them of 22.87 % (51 out of 223). In 28 cases, the fetuses were carriers, 20 of these couples (71.43 %) decided to terminate the pregnancy; the rest continued the pregnancy to term, this resulting in a predictive test for their unborn children. A predominance of females as the at-risk progenitor was observed. Except for a slightly lower average age, the results attained in the Cuban SCA2 prenatal diagnosis program resulted similar to the ones reported for Huntington disease in other countries. It is necessary to have easy access to the Cuban program through its expansion to other genetic centers along the island. Future research is needed to evaluate the long-term impact of both the predictive testing in unborn children and the selection of other reproductive options by the at-risk couples.

Prenatal testing for Huntington's disease in the Netherlands from 1998 to 2008

This study aims to give an overview of the number of prenatal tests for Huntington's disease (HD), test results, and pregnancy outcomes in the Netherlands between 1998 and 2008 and to compare them with available data from the period 1987 to 1997. A total of 126 couples underwent prenatal diagnosis (PND) on 216 foetuses: 185 (86%) direct tests and 31 (14%) exclusion tests. In 9% of direct tests the risk for the foetus was 25%. Four at-risk parents (4%) carried intermediate alleles. Ninety-one foetuses had CAG expansions ≥36% or 50% risk haplotypes: 75 (82%) were terminated for HD, 12 (13%) were carried to term; four pregnancies were miscarried, terminated for other reasons or lost to follow-up. Unaffected pregnancies (122 foetuses) resulted in the birth of 112 children. The estimated uptake of PND was 22% of CAG expansion carriers (≥36 repeats) at reproductive age. PND was used by two new subgroups: carriers of intermediate alleles and 50% at-risk persons opting for a direct prenatal test of the foetus. A significant number of HD expansion or 50% risk pregnancies were continued. Speculations were made on causative factors contributing to these continuations. Further research on these couples' motives is needed.