Genetic aspects of mental health disorders are being identified through human genome and family research. Gene discovery makes diagnostic and presymptomatic testing possible. The discovery of a gene mutation for Huntington Disease (HD) enables at-risk persons to request presymptomatic genetic testing. When HD genetic testing is offered through HD testing centers, a multi-visit protocol is followed in which education and counseling are provided for persons considering the option to have HD gene testing. A case study illustrates the clinical and ethical issues regarding privacy and disclosure as well as the personal and family consequences of gene mutation knowledge. Analysis of the impact of genetic knowledge on persons being tested for HD provides a model for the integration of emerging genetic information into mental health nursing practice for other mental health disorders.
Key Words: Huntington Disease, genetic testing, genetic privacy, mental illness
The accomplishment of two goals of the Human Genome Project (HGP), the mapping and sequencing of entire human genome, provides new opportunities for identification of genetic factors associated with common health disorders (Collins, et al., 1998; NHGRI, 2000). The need to fully integrate psychiatric genetics into research exploring the genetic aspects of common diseases was recently identified by a work group convened by the National Institute of Mental Health (Barondes, 1999). As gene mutations for common health problems including mental disorders are identified, screening for mutations that contribute to the prediction of disease risk is likely to become part of health care in a variety of settings. This capability will have important implications for the health of
As gene mutations for common health problems including mental disorders are identified, screening for mutations that contribute to the prediction of disease risk is likely to become part of health care in a variety of settings.
individuals, their families, and for society. In many psychiatric conditions, such as schizophrenia and bipolar disorder, causation is complex with genetic factors being only a portion of the components leading to these conditions (Rutter, Silberg, O. Connor, & Simonoff, 1999). However, in other cases, an alteration in only one gene is necessary to cause a disorder. Huntington disease (HD) is an example of a single gene disorder that includes psychiatric manifestations. HD is also an example of a disorder for which genetic testing can be used to confirm the diagnosis in persons exhibiting features of the disease and to clarify the chance of developing the disorder in persons who are asymptomatic, but at risk, for the disease. Analysis of the impact of genetic knowledge on persons being tested for HD provides a model for the integration of emerging genetic information into mental health nursing practice for other mental health disorders. The purposes of this paper are to describe HD, HD genetics, presymptomatic HD genetic testing as a model for genetics testing in other serious psychiatric disorders, and issues associated with presymptomatic genetic testing. Finally, a case study describes the roles of the nurse in supporting clients who are seeking, managing, and coping with genetic information within the context of HD.
Huntington Disease (HD) is an inherited, progressive, neurodegenerative disorder characterized by involuntary motor movements, dementia, mood disturbances, and affective disorders. HD was first reported by Dr. George Huntington in 1872 when he described a mother and daughter with hereditary chorea (Rushton, 1994). Current prevalence estimates indicate that HD affects approximately 1 in 20,000 people. Although the average age of onset is in the late 30s, the condition may start as early as age 2 years or as late as age 80 years (Jorde, Carey, Bamshad, & White, 1999). Approximately 10% of persons with HD develop symptoms prior to age 20 and another 10% develop symptoms after age 60 (Rosenblatt, Ranene, Nance, & Paulsen, 1999). The time from diagnosis to death is typically 15 years (Jorde, et al., 1999). Death is usually due to consequences of immobility, general debilitation, and malnutrition, with pneumonia and heart failure being the usual immediate causes of death (Rosenblatt, et al., 1999).
The primary clinical features of HD are progressive chorea, rigidity, and dementia. Additional psychiatric problems in persons with HD are also common and devastating in HD (Rosenblatt, et al., 1999). In a study of 110 persons with HD from 30 families, Schiwach (1994) reported a 72% prevalence of significant personality changes, 39% prevalence of depression, and 9% prevalence of schizophrenia. While the depression associated with HD may be attributed to a response to having the disease, depression in these individuals appears to be directly related to the disorder and is responsive to treatment (Rosenblatt, et al., 1999).
Huntington Disease Genetics
HD is associated with an unstable trinucleotide (CAG) repeat in the IT15, or huntingtin, gene located on the short arm of chromosome 4 (4p16.3) (The Huntington's Disease Collaborative Research Group, 1993). Nucleotides are the molecules that comprise DNA and include adenine (A), guanine (G), cytosine (C), and thymine (T). A trinucleotide repeat is a recurring pattern of three nucleotides. In HD, a CAG repeat within the IT15 gene less than 27 repeats in size is within the normal range. Persons with CAG repeats in the intermediate range of 27-35 repeats are not likely to manifest signs of HD. However, repeats in this range have been found to be unstable during meiosis, and the CAG repeat size may expand to a disease size allele when passed on to offspring (Chong, et al., 1997; Nance, 1996). Persons with CAG repeat sizes of 36-39 in the HD gene may or may not manifest the disorder, a phenomenon referred to as incomplete penetrance. Persons who are found to have an expanded CAG repeat in the IT15 gene that is > 40 repeats in length are expected to develop HD.
Although the HD gene mutation has been identified, the specific functional impact of an altered HD gene on cellular function of brain cells is not well understood. Consequently, gene identification has not yet led to new treatments to change the course of the disorder. However, gene identification in HD has facilitated research in related areas. For example, research is underway to study the relationship between CAG repeat length and phenotypic characteristics
Although the HD gene mutation has been identified, the specific functional impact of an altered HD gene on cellular function of brain cells is not well understood.
such as age at onset and disease severity. Gene identification also allows improved observation and characterization of disease onset. Studies of neuropsychological functioning of persons with expanded trinucleotide repeats in the IT15 gene are mixed regarding whether or not cognitive and behavioral changes can be detected prior to clinical detection of motor symptoms of HD. A two-year study of clinically asymptomatic individuals with mutations in the HD gene did not reveal neuropsychological deficits (Campodonico, Codori, & Brandt, 1996). However, another group of researchers identified deficits in cognitive function in asymptomatic individuals who carried a HD gene mutation (Foroud, et. al., 1995). One explanation may be the differences in ages of the samples in the two studies. Those in the Foroud, et al. study were near the average age of onset of HD, while the subjects in the study by Campodonico and colleagues were, on the average, 9 years younger than the expected age of onset of HD. It may be that neuropsychological deficits do not appear until near the time of onset of other symptoms of HD. However, longitudinal data will be needed needed to test this hypothesis (Campodonico, et. al., 1996; Foroud, et al., 1995).
HD is inherited in an autosomal dominant manner. Autosomal dominant disorders require a gene mutation in only one member of a gene pair for the condition to appear. Consequently, HD is equally prevalent among males and females. In addition, each offspring of a parent with the HD gene mutation has a 50% chance of inheriting the expanded CAG repeat.
Presymptomatic Genetic Testing
Once the gene mutation for HD was identified, it became possible to offer testing to people who have a family history of HD, for purposes of predicting the likelihood of developing the condition later in life. This process is termed presymptomatic testing (Secretary's Advisory Committee on Genetic Testing, 2000). Presymptomatic testing through direct gene mutation detection has been offered for HD since 1993. A model protocol for centers offering presymptomatic gene testing for HD was developed by a committee consisting of representatives of the International Huntington Association and the World Federation of Neurology Research Group on HD (Table 1) (Went, et al., 1994). The protocol recommends that HD genetic testing be offered through genetic counseling or neurology clinics and be staffed by a multidisciplinary team generally consisting of geneticists,
The protocol recommends that HD genetic testing be offered through genetic counseling or neurology clinics and be staffed by a multidisciplinary team
neurologists, genetic nurses, genetic counselors, social workers, and psychologists. HD genetic testing is conducted by DNA analysis and requires a blood sample that is sent to a reference laboratory. The protocol for testing requires a minimum of three visits to the genetic testing program, and states that a support person must accompany the at-risk individual to all visits. One of the first components of the protocol is a physical examination to determine if the person is manifesting any signs of HD. The first two appointments include physical examination, assessment of the person's emotional state, discussion of the benefits and risks of testing, and providing the individual with the opportunity to make an informed decision about proceeding with testing. If the individual decides to proceed with testing, the blood sample may be obtained at the second visit. If the person wants to receive the results, they are communicated at a subsequent face to face visit with the genetic testing staff. A minimum of two months is required to complete the gene test protocol from the initial visit to the disclosure of results.
From the beginning of presymptomatic HD testing, it was determined that the testing would not be offered to minors. This is consistent with the position taken by a joint committee of the American Society of Human Genetics and the American College of Medical Genetics that recommended that genetic testing should generally be deferred in children when no medical or psychosocial benefits to the child are present (ASHG/ACMG Report, 1995).
Several features of the HD genetic testing protocol are well suited for integration into genetic testing protocols for other mental health disorders. One of these features is the requirement that at-risk persons be counseled regarding the full range of potential benefits and risks associated with presymptomatic genetic testing. Adequate time is required for a client to establish rapport with providers as well as receive and synthesize new and complex information. In addition, the potential impact of the test results on the client and their family can be profound, and it is believed that time to consider the potential consequences of the decision is a necessary part of this process. As a result, at least one month's time is recommended between the initial counseling session and the client's decision about whether or not to proceed with testing.
Face to face counseling with health care providers is another important feature of the HD genetic testing protocol. Test results, in particular, are to be given only in person, not by telephone or mail.
...a unique feature of HD genetic testing protocols is the recommendation that at-risk persons be accompanied by a companion or support person...
The requirement for face to face discussions with the health care providers is essential for ongoing assessment of the client's emotional and physical state throughout the testing discussions and at the time of disclosure of results.
A third feature of HD genetic testing is the provision of information through a multidisciplinary team who have received appropriate education on presymptomatic testing and the potential implications for a person's future health and well being. Finally, a unique feature of HD genetic testing protocols is the recommendation that at-risk persons be accompanied by a companion or support person during the entire testing and reporting process. This requirement results in the involvement of family members and friends, who can monitor the at-risk person's reactions and general well being as well as provide ongoing support throughout the testing process.
Although the initial desire for HD presymptomatic testing among at-risk people was strong, it is estimated that about 10-15% of at-risk people actually seek and complete testing (Clarke & Flinter, 1996). Data from the approximately 40 predictive testing centers in the U.S. shows that the total number of tests reported for the three year period from 1996-1998 is approximately 1000 predictive HD tests (Nance, 1999). Although the tests are highly accurate, current presymptomatic testing does not mean that the results can be used to offer new treatment options for persons who are likely to develop HD. Other factors associated with the decision to be tested by persons at risk for HD include believing they can emotionally handle the results, expecting that results will give them a sense of control over their future, seeking a reduction in anxiety or uncertainty, and expecting results will be useful in planning and decision making (Codori, Hanson, & Brandt, 1994; Meissen, et. al., 1991, Tibben, et. al., 1993). Reasons for not having the test may include the limited usefulness of test results for symptom management of the disease, fears regarding impact of the results, and the irreversibility of knowledge of test results.
Experiences in Presymptomatic HD Genetic Testing
Adults requesting genetic testing for HD may experience both benefits and harms from the testing. Benefits include emotional relief from the uncertainty of not knowing if a person has the gene mutation or not. People also request testing so that they can learn if their children are at risk to develop HD and to make future plans for their own lives (Williams, Schutte, Evers, & Forcucci, 1999). When the test shows that the person does not have the gene mutation, the anticipated sense of emotional relief is often accompanied by personal sorrow and worry for those
Adults requesting genetic testing for HD may experience both benefits and harms from the testing.
family members who have HD or who may still develop the disease (Williams, Schutte, Holkup, & Evers, 2000). Some individuals who learn they do not have the HD gene have difficulty coping with their new status; and they report feelings of disappointment when learning their HD gene status did not alleviate prior problems in their lives (Codori & Brandt, 1994; Huggins, et al., 1992). Although psychological distress is increased in people who test positive, most persons remain within normal limits (Tibben, et. al., 1997). Adverse outcomes, including suicide or psychiatric episodes have not been found to exceed background risks for this population (Almqvist, Bloch, Brinkman, Craufurd, & Hayden, 1999). The range of suicide reported to be the result of HD is reported to be from 0.5%-12.7% (Harper, 1996). However, data regarding suicides among persons having HD testing reflects a relatively short period of time of follow up after testing, and it is not known if the suicide rate will increase or decrease as time passes (Bird, 1999).
Another concern associated with presymptomatic genetic testing is loss of genetic privacy. The results of a genetic test will reveal information not only about an individual's genetic makeup, but also reveal something about others who are biologically related and who may share the same gene mutation. A component of informed consent for genetic testing includes consideration of the implications of the test results for other family members. A related issue is the need to determine to whom the results will be disclosed, both within the family, as well as to third parties (Scanlon & Fibison, 1995). Some people who have gene mutations are concerned that they may not be able to obtain, or afford insurance coverage if their insurance provider has access to genetic testing results. Many states have enacted genetic privacy laws. However, the effect of these laws on insurer behavior is unknown (Jaeger & Mulholland, 2000). Even if a person asks that information
Another concern associated with presymptomatic genetic testing is loss of genetic privacy.
about genetic testing or the results of the test not be placed in his/her medical record, confidentiality of this information can not be guaranteed.
One study of persons who have completed HD testing also offers some insights into the impact of test results on third parties. Persons who learned they did not have the HD gene mutation through DNA testing reported a variety of experiences regarding insurability (Williams, Schutte, Evers & Holkup, 2000). Some persons reported that they had been unable to obtain insurance prior to testing due to having HD in their family history. One man found that his insurance provider denied his request for payment of the HD test, due to the provider's assumption that the test would be positive. Another person described her loss of her job after she answered her employer's questions about HD and the fact that she was at risk.
Federal legislation has been passed that is intended to provide some protection for personal genetic information, and bills continue to be considered to regulate insurer and other third-party use of genetic information. The Health Insurance Portability and Accountability Act of 1996 is federal legislation that prevents group health plans from using genetic information to determine insurance eligibility, to limit, or deny benefits using a pre-existing condition exclusion. However, it contains no provisions to prevent insurers from excluding coverage for a specific condition or charging higher premiums to those with gene mutations (Scanlon, 1997). It also does not pertain to insurance plans that are not part of group health plans.
There is also the potential for a wide range of reactions within a person's family. Many persons have difficulty revealing their negative test results to relatives who have HD or with their caregivers. In some cases, the decision to be tested, as well as the results, are not shared with family members who are perceived to be critical or disapproving of the decision to be tested (Williams, Schutte, Holkup, Evers, & Muilenburg, 2000). Family coping may be disrupted when beliefs regarding who was preselected to develop HD are inconsistent with actual test results (Kessler, 1988; Sobel & Cowan, 2000). Prior roles of family members may be altered. For example, persons who learn they do not have the gene mutation may anticipate becoming the caregivers for others in the family who will become ill and will die from HD (Sobel & Cowan, 2000). Many of those who served as companions or support persons throughout the testing process report that the experience was difficult for them, and they felt their own futures, as at-risk persons or as future caregivers were also being revealed (Williams, Schutte, Holkup, Evers, & Muilenburg, 2000).
In summary, presymptomatic genetic testing can identify the presence of a mutation in the gene for HD in persons who are clinically healthy. The test does not allow one to predict when the disease will occur in a person who has >40 CAG repeats in the huntington gene. Genetic testing also raises questions regarding a person's ability to cope with the gene test results, the implications of gene identification for family members, and concerns about genetic privacy.
Huntington Disease Case Study
Brad, a 20-year old male college student in the rural Midwest, contacted his primary care provider about the availability of genetic testing for Huntington disease. The following information was elicited from Brad during an office visit with his family nurse practitioner (FNP). Brad has known of his increased risk for HD since age 15, when his paternal grandfather was diagnosed with the progressive neurodegenerative disorder. Recently there has been talk amongst the family that Brad's paternal great-aunt may also be showing signs of the disorder. Brad's immediate family is aware of the availability of genetic testing for HD. However, there is little discussion about the possibility of pursuing presymptomatic genetic testing. In fact, in one of their few discussions about the disorder, Brad's father was insistent about not knowing his HD gene status and states he will deal with matters if and when they happen. Brad, on the other hand, is motivated to pursue information about presymptomatic genetic testing at this time to inform life planning and family planning decisions. Specifically, he is a college junior with an undecided major and recently became engaged to be married.
The FNP supplemented this initial client interview with a family health history interview. In general, the family health history interview collects information about the age and current health status or age and cause of death for 3-4 generations of Brad's family. Given time constraints and the nature of Brad's questions, the FNP interview focused initially on mid to late-onset neurologic problems, family history of cognitive problems, history of institutionalization, as well as reasons for institutionalization. In addition to gathering health and family health history information, the FNP conducted a complete physical exam, with a focused neurologic assessment and a brief cognitive screen. All aspects of this examination were within normal limits. Brad states that he has not noticed any symptoms suggestive of HD with his father or himself. Brad mentions, however, that he wonders about himself sometimes, especially when he trips or does something clumsy. He wonders if this is the beginning of the disease.
Given Brad's questions about genetic testing and his positive family history for HD, Brad's FNP discusses the option of a referral to a regional outreach genetic counseling program. Genetic specialist providers could offer Brad detailed information about HD genetics, his chances of developing HD given the known family information, the usefulness of HD gene testing in Brad's situation, the presymptomatic HD gene testing protocol, and the potential benefits and risks of genetic testing. Brad agreed with initiating a referral to a genetic specialist provider.
The FNP documented a plan of care for Brad based on his nursing diagnoses of Increased risk for a genetic condition, Knowledge deficit regarding HD, genetics, and genetic testing, and Anxiety. She identified expected nursing outcomes, and carried out activities for specific nursing interventions including conducting risk identification for a genetic disorder and providing genetic counseling activities (Table 2). The FNP used several web-based resources in her preparation for Brad's office visit and in the development of his plan of care. For example, On-line Mendelian Inheritance in Man (OMIM) provides up-to-date information and citations on the genetic basis of more than 4000 genetic conditions. In addition, web sites for the International Society of Nurses in Genetics, Inc. (ISONG) (http://www.isong.org/) and the National Society of Genetic Counselors (NSGC) http://www.nsgc.org) provide resources in locating genetic specialist providers.
Nursing Interventions and Selected Nursing Actions:
The following month Brad attended a regional genetics clinic in a nearby city to discuss presymptomatic HD testing. Prior to the clinic appointment, a Genetics Advanced Practice Nurse (GAPN) conducted a telephone interview with Brad to expand the family history and to explore Brad's goals, questions, and concerns for the upcoming session. The GAPN presented Brad's story to the full HD genetic testing team prior to the clinic visit, where it was agreed that the GAPN would be the initial and primary genetics provider for Brad.
The HD genetic clinic protocol guided the GAPN during her initial clinic visit with Brad. While the goal of this visit was to review the potential benefits and risks of HD testing, the nurse explored three priority areas with Brad - family dynamic issues, life planning issues, and finance/insurance issues. Brad's father's feeling about HD genetic testing presented particular challenges for Brad in his decision making. For example, if Brad's test were positive (i.e. he carried the expanded trinucleotide repeat and therefore could be expected to develop HD at some time in his life), this would mean that Brad's father carriers the disease-causing mutation as well. Given his father's desire not to know, how would this information affect his father and their relationship? Would other family members be supportive of Brad's participation in genetic testing? Would it be possible or desireable to pursue testing without his family's knowledge? Would Brad's father be willing to attend a genetic clinic visit with Brad to learn more about HD testing?
The GAPN also explored the impact of seeking presymptomatic genetic testing upon Brad's life planning decisions. Is Brad's fiancÃ©e aware of Brad's risk for HD? How does Brad see his fiancÃ©e being involved with this process? How will knowing or not knowing his HD gene status affect Brad's decisions regarding a course of study and/or career goals? Finally, the GAPN discussed the potential financial ramifications of presymptomatic HD genetic testing. HD genetic testing is currently available for approximately $255-$300. This cost would not include fees for the clinic visits and genetic counseling. Would Brad prefer to pay for these costs out-of-pocket or submit them to a health care insurer? Does Brad carry his own insurance policy, or is he insured under his parent's policy? Will there likely be a change in insurance carrier in the next 2-5 years?
Based upon this initial visit, Brad decided to take some additional time to contemplate the information provided at the clinic and to think through the potential impact of a positive or negative gene test result upon his own well-being as well as his relationship with his family and fiancÃ©e. At subsequent visits, Brad would meet with the GAPN and other members of the presymptomatic HD testing team. The GAPN also implemented a plan of care for Brad that was based on the same nursing diagnoses and outcomes identified by the FNP (Table 3). The GAPN could refer Brad to other members of the HD team for further neurologic or psychologic evaluation had it been indicated. In addition, the GAPN had several web-based resources available to her as well in implementing Brad's care, including OMIM (http://www.ncbi.nlm.nih.gov/omim/) and GeneTests (http://www.genetests.org). The GeneTests site provides information about the availability of specific genetic tests (i.e. if they are available on a clinical vs. research basis, and those centers or labs offering the test).
Increased risk for genetic condition (HD, based upon reported family history) Nursing Outcome:
Decision-making ability Nursing Interventions and Selected Nursing Activities:
Risk identification: genetic
Shortly after the regional genetic clinic appointment, both Brad and his FNP received a summary letter from the GAPN and geneticist, reviewing the information and options that were discussed at the session. The FNP called Brad shortly after receiving the genetics summary letter to provide emotional support, to provide clarification of the information if needed, and to inquire about Brad's wishes for follow-up. The FNP also offered Brad information about support services offered to families through the Huntington Disease Society (http://www.hdsa.org) and through the Alliance of Genetic Support Groups (http://www.geneticalliance.org ). Brad indicated that he would contact the FNP in the future if and when he decided to pursue testing, and he requested no planned follow-up at this time.
Case Study Discussion
In this case study the primary care provider performed critical interventions in identifying an individual appropriate for a referral to genetic specialist services. The FNP initiated the referral, and then followed up with the client to provide clarification, additional information, and support. The nursing diagnoses, outcomes, and interventions selected by the primary care provider and specialist provider were very similar. The primary difference in the plans of care is evident at the level of activities within the nursing interventions implemented by the two providers. The FNP provided interventions based upon her knowledge that genetic testing was available for a certain disorder and was therefore an option for a client. However, the GAPN provided the actual estimates of her client's risk for a genetic condition based upon phenotype, family history, and/or genetic test results.
While the nature of nursing interventions differed between the two providers in this case study, there were also similarities in their delivery of care. In both cases, the nurses recognized that the client's needs were taking place within the larger family and life context. enabling their client to explore many perhaps otherwise unrecognized potential issues. In addition, genetics interventions were provided in a non-directive manner in both settings. It would be inappropriate for either provider to recommend or encourage presymptomatic genetic testing for a client. Both providers, in contrast, appropriately informed Brad that genetic testing was one option available to him in his pursuit of health and quality of life.
In this case study, follow-up actions were triggered, even though the client chose not to pursue genetic testing at this point in his life. Had the client undergone genetic testing, intensive follow-up assessments and interventions would have been required by both the primary care and specialist providers, regardless of the test outcome. Post-test follow-up would be essential to monitor Brad for untoward effect and to assist Brad in coping with and integrating genetic health information into his life plan.
Finally, the integrity and effectiveness of the genetics interventions discussed in this case study rested, in part, upon excellent coordination and communication between the primary care setting and genetic specialty setting. In this case, each nurse provider contributed different nursing activities aimed at the same nursing diagnoses. Both the primary care and specialist providers were necessary to ensure the implementation of a comprehensive and ongoing plan of care for their client.
Implications for Nursing Practice
The above case study illustrates several important implications for nurses across settings who interact with clients that are seeking, managing, or coping with genetic information. An essential component of all professional nursing services is the need for clients to receive accurate information in the absence of coercion or fear of discrimination. This is especially pertinent for persons who are at risk for HD or for any other mental health disorder with an inherited component. The HD genetic testing protocol is consistent with the ANA Code of Ethics (American Nurses Association, 1985) in which freedom from coercion and adherence to the principle of autonomy is an element of the foundation of ethical nursing practice. This freedom from coercion also encompasses the nurse's respect for a person's right not to know his or her genetic makeup. This is especially critical when disclosure of genetic testing results is contemplated, or when the parent of an at-risk person does not wish to know his or her own gene mutation status.
In order for nurses to help people obtain this level of health care during the genome age, however, nurses must be educated in the principles not only of ethical practice, but also of human genetics. For example, all nurses must have the skills to obtain an accurate and complete family history and to incorporate that information into an appropriate plan of care. Family history assessment is specified as an essential outcome of Baccalaureate Education by the American Association of Colleges of Nursing (1998). When a nurse is evaluating the presence of HD in a family,
Perhaps one of the most critical elements of professional nursing practice for persons seeking, managing or coping with genetic information is client advocacy.
essential skills will include respecting confidentiality of information, determining the client's understanding of the inheritance of the disorder, determining the client's desire for information, providing information within the limits of the nurse's knowledge, evaluating the client's emotional response to information, and referring the client to specialists. These actions are all consistent with the basic level of genetic nursing practice as defined in the Statement on the Scope and Standards of Genetics Clinical Nursing Practice, a document approved by the American Nurses Association (ISONG, 1998).
Perhaps one of the most critical elements of professional nursing practice for persons seeking, managing or coping with genetic information is client advocacy. The health care implications of a presymptomatic DNA test for HD are different than most diagnostic or screening tests. Genetic information, such as HD gene mutation identification, can have profound consequences for a client and their family. Furthermore, the results reveal information not only about the client's risk status, but also about the risk status of other biologic relatives who may not have requested that anyone obtain this information. The impact of discoveries regarding genetic aspects of other mental illness disorders upon the self-concept of persons with mental illness and their family members is unknown. Nursing interventions to help persons cope with personal genetic information about mental health conditions obtained through genetic testing must be developed and tested.
Implications for Mental Health Services
New genetic information and technologies also have implications for the provision of mental health services on multiple levels. On one level, genetic technology and genetic nursing interventions are relevant to the care of increasing numbers of populations experiencing psychiatric and mental health conditions. The National Institute of Mental Health has a mental health focused page on genetics of psychiatric disorders at http://www.nimh.nih.gov/ that may be accessed by health providers and the general public. In addition to HD, researchers are investigating genetic factors in disorders including Tourette syndrome, attention deficit disorder, oppositional and conduct disorders, drug and alcohol problems, and
Emotional distress, including sadness, worry, and survivor guilt, was also reported by persons in the first six months after testing when they learned they did not have the gene mutation for HD
autism (Rutter, et al., 1999; Ryan, 1999) with schizophrenia and bipolar disorder being identified as preferred conditions for large-scale studies (Barondes, 1999). Understanding implications of these discoveries for mental health will be essential for nurses who will integrate this knowledge into assessment of client symptoms and appropriate interpretation of family history information.
On another level, the use of genetic information by clients, regardless of population and setting, holds potential mental health sequelae. For example, one group of researchers reported that emotional distress regarding perception of risk for breast cancer in women with this family history remained unchanged over time following genetic counseling (Watson, et al., 1999). Emotional distress, including sadness, worry, and survivor guilt, was also reported by persons in the first six months after testing when they learned they did not have the gene mutation for HD (Williams, Schutte, Evers & Holkup, 2000).
On both levels, the experiences of clients seeking genetic information related to HD provides a template for the integration of genetic health care services into the care of other populations. Most mental health disorders are not likely to be related to mutations in a single gene. However, discovery of these genes may lead to development of susceptibility testing in which biologic information is revealed through genetic testing. Health care services for HD now include a methodical and carefully delineated protocol that considers the multiple clinical and ethical concerns that are involved in genetic health care. This protocol also relies on the collaboration of multiple care providers within the testing situation as well as collaboration between genetic specialists and community based health professionals. However, there are numerous questions regarding genetic testing that are not yet answered. The ability of informed and competent providers to support clients across the care continuum in the acquisition and use of genetic information is a critical prerequisite to the successful integration of genetic information into the delivery of comprehensive mental health care services.
Janet K. Williams PhD, RN, CPNP, CGC
Janet K. Williams, PhD, RN, CPNP, CGC is an Associate Professor at the College of Nursing, The University of Iowa. She has conducted funded research on the psychosocial impact of genetic testing upon people at risk for Huntington Disease and on their family members.
Debra L. Schutte, MSN, RN is a PhD candidate at the College of Nursing, The University of Iowa. She is conducting research on genotype/phenotype relationships in Alzheimer disease and has conducted research on the psychosocial aspects of predictive testing for Huntington Disease.
American Association of Colleges of Nursing (AACN) (1998). The essentials of baccalaureate education for professional nursing practice. Washington DC: American Association of Colleges of Nursing.
Almqvist, E., Bloch, M., Brinkman, R., Craufurd, D., and Hayden, M. On behalf of an international Huntington disease collaborative group (1999). A worldwide assessment of the frequency of suicide, suicide attempts, or psychiatric hospitalization after predictive testing for Huntington disease. American Journal of Human Genetics, 64, 1293-1304.
American Nurses Association (1985). Code for nurses with interpretive statements. Kansas City, MO: American Nurses Association.
ASHG/ACMG Report (1995). Points to consider: ethical, legal, and psychosocial implications of genetic testing in children and adolescents. American Journal of Human Genetics, 57, 1233-1241.
Barondes, S.H. (1999). An agenda for psychiatric genetics. Archives of General Psychiatry, 56, 549-552.
Bird, T.D. (1999). Outrageous fortune: The risk of suicide in genetic testing for Huntington disease. American Journal of Human Genetics, 64, 1289-1292.
Campodonico, J., Codori, A., & Brandt. J. (1996). Neuropsychological stability over two years in asymptomatic carriers of the Huntington's disease mutation. Journal of Neurology, Neurosurgery, and Psychiatry, 61, 621-624.
Chong, S.S., Almqvist, E., Telenius, H., LaTray, L., Nichol, K., Bourdelat-Parks, B., Goldberg, Y., Haddad, B., Richards, F., Sillence, D., Greenberg, C., Ives, E., Van den Engh, G., Hughs, M., & Hayden, M. (1997). Contribution of DNA sequence and CAG size to mutation frequencies of intermediate alleles for Huntington disease:evidence from single sperm analyses. Human Molecular Genetics, 6 (2), 301-309.
Clarke, A., & Flinter, F. (1996). The genetic testing of children: A clinical perspective. In T. Marteau & M. Richards (eds.). The troubled helix: Social and psychological implications of the new human genetics, pp.164-176. Cambridge: Cambridge University Press.
Codori, A., & Brandt, J. (1994). Psychological costs and benefits of predictive testing for Huntington disease. American Journal of Medical Genetics, 54, 174-184.
Codori, A., Hanson, R., & Brandt, J. (1994). Self-selection for predictive testing for Huntington's disease. American Journal of Medical Genetics (Neuropsychiatric Genetics), 54, 167-173.
Collins, F.S., Patrinos, A., Jordan, E., Chakravarti, A., Gesteland, R., Walters, L., and the members of the DOE and NIH planning groups (1998). New goals for the U.S. Human Genome Project. Science, 282, 682-689.
Foroud, T., Siemers, E., Kleindorfer, D., Bill, D., Hodes, M., Norton, J., Conneally, P.M., & Christian, J. (1995). Cognitive scores in carriers of Huntington's disease gene compared to noncarriers. Annals of Neurology, 37(5), 657-664.
Harper, P. S. (1996). Huntington's disease. 2nd Ed. London: W.B.Saunders
Huggins, M., Bloch, M., Wiggins, S., Adam, S., Suchowersky, O., Trew, M., Klimek, M., Greenberg, C., Eleff, M., Thompson, L, Knight, J., MacLeod, P. Girard, K., Theilman, J., Hedrick, A., & Hayden, M. (1992). Predictive testing for Huntington disease in Canada: Adverse effects and unexpected results in those receiving a decreased risk. American Journal of Medical Genetics, 42, 508-515.
Iowa Intervention Project (2000). Nursing interventions classification (NIC) J.C.McCloskey & G.M. Bulechek (eds.) (4th ed.). St. Louis: Mosby.
Iowa Outcomes Project (2000). Nursing outcomes classification (NOC). M. Johnson, M. Maas, & S. Moorhead (eds.) (2nd ed.). St. Louis: Mosby.
ISONG (1998). Statement on the Scope and Standards of Genetics Clinical Nursing Practice, Washington DC: American Nurses Association.
Jaeger, A.S., & Mulholland, W.F. (2000). Impact of genetic privacy legislation on insurer behavior. Genetic Testing, 4(1), 31-42.
Jorde, L., Carey, J. Bamshad, M., & White, R. (1999). Medical genetics. 2nd ed. St. Louis: Mosby.
Kessler, S. (1988). Preselection: A family coping strategy in Huntington disease. American Journal of Medical Genetics, 31, 617-621.
Meissen, G., Mastromauro, C., Kiely, D., McNamara, D., & Myers, R. (1991). Understanding the decision to take the predictive test for Huntington disease. American Journal of Medical Geneticsl 39, 404-410.
Nance, M.A. (1996) Invited Editorial "Huntington Disease--Another Chapter Rewritten", American Journal of Human Genetics, 59,1-6.
Nance, M.A. (1999, October). Trends in predictive testing-Duration of a testing program. Paper presented at the meeting of the United States Huntington Disease Genetic Testing Group, San Fransisco, CA.
NANDA (1996). Nursing diagnoses: Definitions & classification 1997-1998. Philadelphia, PA: North American Nursing Diagnosis Association.
NHGRI (June 26, 2000). International Human Genome Sequencing Consortium Announces "Working Draft" of Human Genome. www.nhgri.nih.gov/NEWS/sequencing_consortium.html
Rosenblatt, A., Ranen, N., Nance, M., & Paulsen, J. (1999). A physician's guide to the management of Huntington's disease. (2nd ed.). New York: Huntington's Disease Society of America.
Ryan, S.G. (1999). Genetic susceptibility to neurodevelopmental disorders. Journal of Child Neurology, 14, 187-195.
Rushton, A. (1994). Genetics and Medicine in the United States 1800-1922. The Johns Hopkins University Press.
Rutter, M., Silberg, J., O. Connor, T., & Simonoff, E. (1999). Genetics and child psychiatry: II Empirical research findings. Journal of Child Psychology and Psychiatry, 49 (1), 19-55.
Scanlon, C. (1997). Genetic testing, the law, and you. Office Nurse, 44,46,49.
Scanlon, C., & Fibison, W. (1995). Managing genetic information: Implications for nursing practice. Washington, DC: American Nurses Publishing.
Shiwach, R. (1994). Psychopathology in Huntington's disease patients. Acta Psychiat. Scandinavia, 90: 241-246.
Secretary's Advisory Committee on Genetic Testing (2000). A public consultation on oversight of genetic tests. Bethesda MD: National Institutes of Health. Retrieved September 10, 2000 from the World Wide Web: www4.od.nih.gov/oba/sacgt.htm
Sobel, S., & Cowan, D.B. (2000). The process of family reconstruction after DNA testing for Huntington disease. Journal of Genetic Counseling, 9(3), 237-251.
The Huntington's Disease Collaborative Research Group (1993). A novel gene containing a trinucleotide repeat that is expanded and unstable in Huntington's disease chromosomes. Cell, 72, 971-983.
Tibben, A., Frets, P., van de Kamp, J., Niermeijer, M., Vegter-van der Vlis, M., Roos, R., van Ommen, G., Duivenvoorden, H., & Verhage, F. (1993). Presymptomatic DNA-testing for Huntington disease: Pretest attitutdes and expectations of applicants and their partners in the Dutch program. American Journal of Medical Genetics (Neuropyschiatric Genetics), 48, 10-16.
Tibben, A., Timman, R., Bannink, E., Duivenvoorden, H. (1997). Three-year follow-up after presymptomatic testing for Huntington's disease in tested individuals and partners. Health Psychology, 16(1): 20-35.
Watson, M., Lloyd, S., Davidson, J., Meyer, L., Eeles, Ebbs, S., & Murday, V. (1999). The impact of genetic counselling on risk perception and mental health in women with a family history of breast cancer. British Journal of Cancer, 79, 868-874.
Went, L., Brohom, J., Cassiman, J., Craufurd, D., Falek, A., Farmer-Little, C., Hayden, M., Kapp, R., Krahnen, K., Martinex-Descals, A., Mol, M. Myrinathopoulos, N., Petit, H., Quaid, K., DeSomviele, C., Taylor, E., Tyler, A. Walker, R., & Wexler, N. (1994). Guidelines for the molecular genetics predictive test in Huntington's disease. Journal of Medical Genetics, 31, 555-559.
Williams, J.K., Schutte, D.L, Evers, C., & Forcucci, C. (1999). Adults seeking presymptomatic gene testing for Huntington disease. Image: Journal of Nursing Scholarship, 31(2), 109-114.
Willams, J.K., Schutte, D.L., Evers, C., & Holkup, P.A. (2000). Redefinition: Coping with normal results from presymptomtic gene testing for neurodegenerative disorders. Research in Nursing and Health, 23, 260-269.
Williams, J.K., Schutte, D.L., Holkup, P.A., Evers, C., & Muilenburg, A. (2000). Psychosocial impact of predictive testing for Huntington disease on support persons. Neuropsychiatric Genetics, American Journal of Medical Genetics, 96(3):353-359.