Uncertainties in genetic testing for chronic disease

Utility and Diversity: Challenges for Genomic Medicine

Genomic information is poised to play an increasing role in clinical care, extending beyond highly penetrant genetic conditions to less penetrant genotypes and common disorders. But with this shift, the question of clinical utility becomes a major challenge. A collaborative effort is necessary to determine the information needed to evaluate different uses of genomic information and then acquire that information. Another challenge must also be addressed if that process is to provide equitable benefits: the lack of diversity of genomic data. Current genomic knowledge comes primarily from populations of European descent, which poses the risk that most of the human population will be shortchanged when health benefits of genomics emerge. These two challenges have defined my career as a geneticist and have taught me that solutions must start with dialogue across disciplinary and social divides.

German and Italian Users of Web-Accessed Genetic Data: Attitudes on Personal Utility and Personal Sharing Preferences. Results of a Comparative Survey (n=192)

Genetic information is increasingly provided outside of the traditional clinical setting, allowing users to access it directly via specialized online platforms. This development is possibly resulting in changing ethical and social challenges for users of predictive genetic tests. Little is known about the attitudes and experiences of users of web-accessed genetic information. This survey analyzes data from two European countries with regard to the utility of genetic information, the users’ ways of making use of and dealing with information, and their sharing behavior. Particular focus is given to ethical and social questions regarding the motivation to share personal genetic results with others. Social factors tested for are national background, gender, and marital, parental, and educational status. This study will contribute to public discourse and offer ethical recommendations. The study will also serve to validate the developed questionnaire for use in population representative surveys.

Misuse (and abuse?) of the Concept of Empowerment.The Case of Online Offer of Predictive Direct-to-consumer Genetic Tests

Using the field of direct-to-consumer genetic tests as a case in point, this paper argues against the misuse of the term empowerment, and calls for a regulation of its usage. The misleading assumption under certain current usages of the concept of empowerment is that it is enhanced by the provision of health information. While the information-empowerment correlation is misleading, if not wrong, the feeling of being empowered imposes an increasing burden of critical thinking on those people (patients and consumers) who have to evaluate that information and act for the benefit of their health.

Evaluating online direct-to-consumer marketing of genetic tests: informed choices or buyers beware?

Commercialization of genetic technologies is expanding the horizons for the marketing and sales of genetic tests direct-to-consumers (DTCs). This study assesses the information provision and access requirements that are in place for genetic tests that are being advertised DTC over the Internet. Sets of key words specific to DTC genetic testing were entered into popular Internet search engines to generate a list of 24 companies engaging in DTC advertising. Company requirements for physician mediation, genetic counseling arrangements, and information provision were coded to develop categories for quantitative analysis within each variable. Results showed that companies offering risk assessment and diagnostic testing were most likely to require that testing be mediated by a clinician, and to recommend physician-arranged counseling. Companies offering enhancement testing were less likely to require physician mediation of services and more likely to provide long-distance genetic counseling. DTC advertisements often provided information on disease etiology; this was most common in the case of multifactorial diseases. The majority of companies cited outside sources to support the validity of claims about clinical utility of the tests being advertised; companies offering risk assessment tests most frequently cited all information sources. DTC advertising for genetic tests that lack independent professional oversight raises troubling questions about appropriate use and interpretation of these tests by consumers and carries implications for the standards of patient care. These implications are discussed in the context of a public healthcare system.

Knowing me, knowing you

Patients are beginning to present with not only a web diagnosis but predictions of future disease. Jeanne Lenzer and Shannon Brownlee examine the problems of the rise in commercial genetic testing

Cascade genetic testing for mismatch repair gene mutations

Mismatch repair gene mutation carriers have a high risk of developing colorectal cancer, and can benefit from appropriate surveillance. A combined population based ascertainment cascade genetic testing approach provides a systematic and potentially effective strategy for identifying such carriers. We have developed a Markov Chain computer model system which simulates various factors influencing cascade genetic testing; including demographics, uptake, genetic epidemiology and family size. This was used to evaluate cascade genetic testing for mismatch repair gene mutations in theory and practice. Simulations focussed on the population of Scotland by way of illustration, and were based on a 20-year programme in which index cases were ascertained from colorectal cancer cases aged<55 years at onset. Results indicated that without practical barriers to cascade genetic testing, 545 (95% CI=522, 568) carriers could be identified; 42% of the population total. This comprised approximately 140 index cases, 302 asymptomatic relatives and 104 previously affected relatives. However, when realistic ascertainment and acceptance rates were used to inform simulations, only 257 (95% CI=246, 268) carriers, about 20% of the carrier population, were identifiable. Of these approximately 112 were index cases, 108 were asymptomatic relatives, and 37 were previously affected relatives. This contrast emphasises the importance of ascertainment and acceptance rates. Likewise the low number of index cases shows that case identification is a limiting factor. In the absence of robust data from epidemiological studies, these findings can inform decisions about the use of cascade genetic testing for mismatch repair gene mutations.

Perceived genetic knowledge, attitudes towards genetic testing, and the relationship between these among patients with a chronic disease

OBJECTIVE

Genetics increasingly permeate everyday medicine. When patients want to make informed decisions about genetic testing, they require genetic knowledge. This study examined the genetic knowledge and attitudes of patients with chronic diseases, and the relationship between both. In addition, patients were asked about their preferred source of genetic information.

METHODS

Questionnaires were mailed to participants of a nationwide representative sample of patients with chronic diseases in the Netherlands (n = 1916).

RESULTS

The response rate was 82% (n = 1496). Perceived genetic knowledge was low, particularly among older and lower educated patients. Attitudes towards genetics were rather positive, especially among younger and higher educated patients. Some concerns were also documented, mainly about the consequences of genetic testing for employment and taking insurance. Patients who perceived to have little knowledge found it difficult to formulate an opinion about genetic testing. Higher levels of genetic knowledge were associated with a more favourable attitude towards genetics. Chronic patients prefer to receive genetic information from their GP.

CONCLUSION

Chronic patients are ill prepared when they require genetic knowledge to make decisions regarding the treatment of their disease. This seems to result from a knowledge deficiency rather than from disagreement with the genetic developments.

PRACTICE IMPLICATIONS

When chronic patients are in need of information about genetics or genetic testing, their general practitioner should provide this.

Ethical issues in genetic testing

Genetic factors contribute to risk for disease. Information clarifying risk in an individual and his/her family members can be identified through clinical screening and genetic testing. In some circumstances, this information can be used in clinical decisions about surveillance and prevention or treatment of disease. However, use of this information is not always a straightforward process. Application of knowledge about risk of genetic disease in provision of primary health care for women requires understanding of new genetic discoveries as well as the ability to participate in resolution of ethical dilemmas that may result when genetic screening and testing are considered. These dilemmas arise not only from the current state of knowledge about genetic risk factors and utility of genetic tests but also result from conflicts that can arise when the needs of the client are not in unison with needs of others within the family or society. Ethical theories and principles provide a framework for resolving ethical dilemmas in maternal screening for genetic conditions during a pregnancy, carrier testing prior to or during a pregnancy, clinical genetic testing, and newborn metabolic screening.

GENETIC TESTING IN PRIMARY CARE

Rapid advances in genetic research are leading to an expanding array of genetic tests. Primary care providers will increasingly be challenged to identify patients whose symptoms, physical findings, or family history indicate the need for genetic testing, and to determine how to use genetic information most effectively to improve disease prevention. In addressing these challenges, practitioners will need to consider the range of different uses of genetic testing, including diagnosis in symptomatic and asymptomatic people, risk assessment, reproductive decision-making, and population screening. They will need a set of core skills and knowledge to evaluate family history and to recognize clinical findings that indicate genetic risk. At the same time, the primary care perspective will contribute to the evaluation of appropriate uses of genetic testing. A partnership between medical genetics and primary care will help to ensure the development of effective policies, educational tools, and practice guidelines for the coming era of genomic health care.

Direct-to-consumer sales of genetic services on the Internet

PURPOSE The increasing use of the Internet to obtain genetics information and to order medical services without a prescription, combined with a rise in direct-to-consumer marketing for genetic testing, suggests the potential for the Internet to be used to sell genetic services. METHODS A systematic World Wide Web search was conducted in May 2002 to assess the availability of genetic services sold directly to consumers on the Internet. RESULTS Out of 105 sites that offered genetic services directly, most offered non-health-related services, including parentage confirmation testing (83%), identity testing (56%), and DNA banking (24%); however, health-related genetic tests were offered through 14 sites (13%). The health-related genetic tests available ranged from standard tests, such as hemochromatosis and cystic fibrosis, to more unconventional tests related to nutrition, behavior, and aging. Of these 14 sites, 5 described risks associated with the genetic services and 6 described the availability of counseling. CONCLUSIONS The availability of direct sales of health-related genetic tests creates the potential for inadequate pretest decision making, misunderstanding test results, and access to tests of questionable clinical value.

Hereditary hemochromatosis: perspectives of public health, medical genetics, and primary care

Hereditary hemochromatosis (HHC) is a condition characterized by excess iron in body tissues, resulting in complications such as cirrhosis, cardiomyopathy, diabetes, and arthritis. These complications usually manifest during adulthood. Two methods of screening for the detection of early stage of HHC are available: serum iron measures and molecular testing to detect mutations in the gene. These phenotypic and genotypic screening tests are of particular interest because a simple treatment-periodic phlebotomy-can be used to prevent iron accumulation and clinical complications. HHC might represent the first adult-onset genetic disorder for which universal population-based screening would be appropriate. Therefore, HHC has been proposed as a paradigm for the introduction of adult genetic diseases into clinical and public health practice. However, universal screening for HHC has not been recommended because of the uncertainty about the natural history of the iron overload or HHC and, in particular, uncertainty about the prevalence of asymptomatic iron overload and the likelihood that it will progress to clinical complications. If universal screening is not appropriate based on current data, what other measures might reduce the disease burden of iron overload? New studies provide more systematic information about the penetrance of the C282Y mutation and shed further light on the natural history of the disorder. The authors review these data and consider their implications for public health, medical genetics, and primary care.

Genetics in medical practice

Medical genetics has been formally recognized as a medical specialty in the United States only within the past decade. Initially, medical genetics was concerned with relatively rare single gene or chromosomal disorders, but with the sequencing of the human genome, genetics has become the driving force in medical research and is now poised for integration into medical practice. This article offers a perspective on the role of genetics in medical practice and how this role may evolve over the next several years. The author classifies the genetic contribution to medical practice into three categories: monogenic or chromosomal disorders, more common disorders due to a monogenic or single gene mutation, and common multifactorial disorders in which the interaction of multiple genes and the environment contribute to the cause of the condition. The author discusses the positives and the potential pitfalls facing primary care physicians and specialists as they incorporate medical genetics into their practices and points out some of the anticipated changes medical genetics will necessitate, such as an increased medical genetics workforce, including geneticists and genetic counselors. The Human Genome Project has made information of inestimable diagnostic and therapeutic importance available. The medical profession now must rise to both the opportunities and challenges that this wealth of information presents.

Genetic counseling for psychiatric disorders

Like other medical conditions, some psychiatric disorders are inherited, whereas others are not. Human genetics research is moving at a rapid pace. Genes for over 450 genetic disorders have been cloned and many disease-causing mutations have also been identified. The explosion of this new knowledge has created many new exciting opportunities in the diagnosis of these heritable disorders. The rapid pace of gene discovery will aid the identification of susceptibility genes for psychiatric disorders. Indeed, we can look forward to answers to many clinical and research questions. These are some of the gifts that the expanding field of human genetics research will continue to bring to medical science. However, as genetic tests for the detection of psychiatric disorders become available, many ethical, legal, and social implications will need to be considered. In this article, we review the principles of genetic counseling for psychiatric disorders, as well as the social and ethical dilemmas that genetic testing may bring. Although medical and scientific advances may bring many gifts, we should approach this new knowledge with caution, as one of the gifts may be a Pandora's box.

Is there a use for tailored print communications in cancer risk communication?

The manner of presentation of cancer risk information is critical to its understanding and acceptance by the individual recipient. Optimal communication of cancer risk information must effectively translate the technical meaning and subtleties of risk and its associated factors to a conceptual level understandable by the recipient. Tailored print communications (TPCs) may be an appropriate medium for cancer risk communication (CRC). TPCs are more refined than targeted communication materials. They are print materials created especially for an individual on the basis of knowledge about that person. The goal is to provide individually relevant and appropriate information. This review examines the nature of TPCs, assesses the use and potential of TPCs for the purpose of CRC, and highlights new directions in CRC. Articles dealing with TPCs were located by searching the MEDLINE(R) and PsychInfo(R) databases and seeking in-press articles. TPCs were identified for several areas of CRC, including dietary change, smoking cessation, mammography use, hormone replacement therapy, health risk appraisal, and genetic susceptibility to cancer. Although TPCs have been used in a number of different behavioral areas, they have not yet achieved their potential for CRC. The use of TPCs in the communication of cancer risk shows great promise, however, particularly as knowledge evolves regarding both the nature of risk and the most effective tailoring of health communication messages.

Risk communication in clinical practice: putting cancer in context

CONTEXT

Clinicians are increasingly urged-even mandated-to help patients make informed medical decisions by paying more attention to risk counseling. For many, the role of risk counseling is new and unfamiliar. This effort is made more difficult given the practical constraints created by 15-minute visits and competing demands (e.g., patient's chief complaint and institutional needs).

OBJECTIVE

We detail a three-part approach for improving risk communication, acknowledging the role of clinicians, patients, and other communicators (i.e., media or public health agencies).

PROPOSED APPROACH

Office-based tools to help clinicians do more. We suggest two ways to help make up-to-date estimates of disease risk and treatment benefit easily available during office visits. We propose the development of a comprehensive population database about disease risk and treatment benefit to be created and maintained by the federal government. Educating patients. We propose "Understanding Numbers in Health" a tutorial that reviews basic concepts of probability and their application to medical studies to help people become better critical readers of health information. Guidance for communicators. Finally, we propose a writer's guide to risk communication: a set of principles to help health communicators present data to the public clearly and objectively.

CONCLUSION

In addition to tools to help clinicians better communicate risk information, serious efforts to improve risk communication must go beyond the clinic. Efforts that help the public to better interpret health risk information and guide communicators to better present such information are a place to start.

Genetic testing, ethical concerns, and the role of patent law

This article examines the changing debate over gene patenting and the possible connection between patent law and the ethical and policy concerns associated with the use of genetic testing technologies (e.g. the premature implementation and inappropriate marketing of genetic tests). Arguably, patent law helps to form the market forces that lead to these concerns. It is suggested that existing safeguards fail to control these concerns because of, for example, a lack of provider knowledge and an absence of an adequate regulatory framework. While patent law can be associated with a number of ethical and policy concerns, the article also suggests that patent law may have a positive role in reducing them. Patent law provides policy makers and the public with a focal point - the patent holder - upon which to attach accountability for ethical and legal conduct. The article concludes by inviting policy makers to consider the ways in which patent law could be modified in order to optimize its constructive influence.

A philosophical critique of decision analysis as a tool in genetic testing

Decision analysis has been proposed as a method to improve the quality of decisions made by individuals facing choices about genetic testing for Alzheimer disease (AD) and other conditions where information about risk is highly uncertain. This paper provides a philosophical critique of two schools of decision analysis, explaining the conceptual limitations inherent in each approach. A central difference between the two approaches is their stance toward the ontological status of patient preferences and values. Are an individual's preferences and values about genetic testing simply assessed or extracted during decision analysis or are they created during the decision analysis itself? How closely can preferences conform to the axioms of rational choice theory? A case study of one individual's experience with decision analysis demonstrates the strengths and weaknesses of decision analysis in the context of genetic testing for AD.

Understanding probabilistic risk in predisposition genetic testing for Alzheimer disease

The utility of genetic testing in preventing the onset of conditions such as Alzheimer disease (AD) depends upon categorizing individuals based on their "risk" of illness. Although no strategies to prevent the occurrence of AD have been proven effective, the promise of the new molecular medicine is based on the assumption that those "at risk" can be identified, counseled about their likelihood of developing a disease, and prescribed specific preventive interventions. We suggest that this paradigm of disease prevention through risk stratification has limitations that have not been fully explored. Within the fields of cognitive and health psychology, research has addressed how individuals understand the numeric presentation of uncertain future events; this research often focuses on the "perceptual pathology" of lay people. The uncertainty inherent in the risk estimates themselves is rarely considered, nor has research addressed how those risk estimates are created. There has been limited work to date focused on genetic risk assessment, and little is known about how individual might understand the meaning or consequences of being at genetic risk for AD. An emerging social science critique of concepts of risk in genetic medicine offers a broader perspective, examining the process of producing scientific risk estimates as well as the response of individual patients, such as the experience of embodied risk that is central to genetic testing. Making fully informed choices about genetic testing for AD may prove more difficult than our current model of ethical practice suggests.

Great expectations: historical perspectives on genetic breast cancer testing

Women who test positive for a genetic breast cancer marker may have more than a 50% chance of developing the disease. Although past screening technologies have sought to identify actual breast cancers, as opposed to predisposition, the history of screening may help predict the societal response to genetic testing. For decades, educational messages have encouraged women to find breast cancers as early as possible. Such messages have fostered the popular assumption that immediately discovered and treated breast cancers are necessarily more curable. Research, however, has shown that screening improves the prognosis of some--but not all--breast cancers, and also that it may lead to unnecessary interventions. The dichotomy between the advertised value of early detection and its actual utility has caused particular controversy in the United States, where the cultural climate emphasizes the importance of obtaining all possible medical information and acting on it. Early detection has probably helped to lower overall breast cancer mortality. But it has proven hard to praise aggressive screening without exaggerating its merits. Women considering genetic breast cancer testing should weight the benefits and limitations of early knowledge.