The intersection of genetics, public health, and preventive medicine

Unwarranted optimism in media portrayals of genetic research on addiction overshadows critical ethical and social concerns

The cost of addiction in the United States, in combination with a host of new tools and techniques, has fueled an explosion of genetic research on addiction. Because the media has the capacity to reflect and influence public perception, there is a need to examine how treatments and preventive approaches projected to emerge from addiction genetic research are presented to the public. The authors conducted a textual analysis of 145 news articles reporting on genetic research on addiction from popular print media in the United States and from popular news and medical internet sites. In articles that report on prevention, the media emphasize vaccine development and identifying individuals at genetic risk through population screening. Articles that emphasize treatment often promote current pharmaceutical solutions and highlight the possibility of tailoring treatments to specific genetic variants. The authors raise concerns about the tendency of this coverage to focus on the benefits of pharmaceutical treatments and genetic-based approaches to prevention while neglecting or downplaying potential risks and ethical issues. This analysis suggests a need for more balanced, evidence-based media reporting on the potential outcomes of genetic research.

Toward a road map for global -omics: a primer on -omic technologies

As highlighted in a recent editorial in the Journal (Am J Epidemiol. 2014;180(2):127-128), the research area of "-omics" includes genomics, proteomics, metabolomics, and nascent fields of scientific inquiry such as epigenomics and exposomics. These fields can be collectively referred to as "global -omics." Increasing efforts have been made over the past 2 decades to identify and modify environmental risk factors among persons who are susceptible to disease because of their genotype and to integrate genetic information and other biological variables with information about individual-level risk factors and group-level or societal factors related to the broader residential, behavioral, or cultural context. In genome-wide association studies, only a small proportion of heritability is explained by genetic variants identified to date, which has prompted researchers in bioinformatics and biostatistics to take into account nonlinear relationships due to gene-environment or gene-gene interactions. The exposome, which is dynamic and variable, consists of all of the internal and external exposures an individual incurs over a lifetime. Both the epigenome and exposome change with age. The prenatal and perinatal periods are thought to be important times for epigenetic marking. Once the human epigenome has been fully mapped, identification of the effects of all deleterious environmental exposures according to duration of exposure and time period will be a complex undertaking, requiring collaborative epidemiologic studies.

Patient attitudes toward genotyping in an urban women's health clinic

OBJECTIVE

To estimate willingness of women to donate specimens for DNA analysis by needlestick compared with collection of saliva.

METHODS

This study was a cross-sectional survey given to women attending clinic appointments asked about their knowledge and attitudes toward genetics research and genotyping.

RESULTS

The majority of the 279 women surveyed would give DNA specimens by needlestick (68.3%) but more would be willing to donate saliva (75.7%), P=.003. An ethnic difference was seen in the replies about needlesticks but not regarding saliva donation. Multivariable analysis demonstrated that women who were likely to donate specimens rated themselves more knowledgeable about genes and DNA (odds ratio 2.43, 95% confidence interval 1.12-5.28) and had graduated from college or higher (odds ratio 6.74, 95% confidence interval 1.98-22.86).

CONCLUSION

More women are willing to donate DNA specimens by saliva than by needlestick. Knowledge and higher education predict a willingness to donate.

LEVEL OF EVIDENCE

III.

Perceptions of genetic testing for cancer predisposition among Ashkenazi Jewish women

BACKGROUND

Clinical genetic testing can help identify individuals who are predisposed to a variety of diseases and conditions; thus, it is important to understand attitudes and perceptions of individuals who may consider or who may be offered such testing.

METHODS

We examined knowledge and attitudes about cancer genetic testing among 59 women of Ashkenazi Jewish descent (age 25-80 years) through six focus group discussions. Participants were asked about their knowledge and experience with hereditary conditions and genetic testing, and attitudes regarding risk management options, genetic privacy, and potential discrimination issues.

RESULTS

Although 54% reported having a personal and/or some family history of breast, ovarian, or colorectal cancer, none had undergone cancer genetic counseling or testing and few expressed an interest or intention in doing so. While most endorsed benefits of genetic testing for those with a significant cancer family history, women also expressed concerns over the possible distress of learning that one carried a cancer-predisposing mutation and suggested that increasing cancer screening practices may be preferable to having genetic testing. Participants doubted the ability of state genetic privacy legislation to protect against insurance or employment discrimination.

CONCLUSION

Findings underscore the need for public education on the broad range of benefits and limitations associated with genetic testing, in order to help consumers to appropriately interpret complex information and make decisions about these services.

Ethics and research assessing the relative roles of genes and the environment

Research on the interaction of genes and the environment is revealing that many human diseases have both genetic and environmental components. Even traditional "environmental" diseases, such as infections, appear to interact with genetic components in the human host. Environmental genetics research will inevitably increase understanding of individual susceptibilities to toxic exposures in the environment and harmful side effects of medications; therefore, it has great promise for improving the prevention and treatment of human diseases. However, realizing the benefits of this research requires careful attention to ethical issues that are particularly relevant in this context. This article reviews some of the most pressing issues related to research design and methods, as well as from the application of research results (e.g., workplace genetic screening and legal toxic torts, personal medical responsibility, and the relationship between genetics and public health measures).

Health motivation and emotional vigilance in genetic testing for prostate cancer risk

Actual uptake of genetic testing for cancer susceptibility is generally lower than 50%, despite a high initial interest above 80%. As population-based genetic testing for cancer susceptibility becomes more widespread, there will be an increasing need to understand the relationship of patient-affective factors to test intention and actual uptake behavior. Using hypothetical genetic testing for prostate cancer susceptibility as an example, we used surveys of 400 men in the general population of Philadelphia to develop a Structural Equation Modeling diagram to reveal the influence of affective factors implicated in the intention to undergo genetic testing for prostate cancer risk. Results showed that most men want genetic testing for prostate cancer, believe strongly in its benefits, and are not deterred by negative affect. Our data suggest that high positive expectations, plus a high desire to comply with physician and family suggestions, result in an increased test intention. Informed consent assessment, therefore, requires an appreciation not only of patient risk, but awareness of patient motivation and affect as well.

Public knowledge regarding the role of genetic susceptibility to environmentally induced health conditions

OBJECTIVE

Diseases thought to be caused by exposure to environmental factors are also influenced by genetic susceptibility. It is not clear to what extent the public recognizes the role of genetics in causing these diseases.

METHODS

We asked 2,353 people in a national survey to indicate their level of agreement with statements about the genetic contribution to four health conditions typically considered to be environmentally induced.

RESULTS

206 (9%) respondents believed that genetic susceptibility contributes to all four health conditions, while 751 (32%) believed that genetics plays no role in causing any of the conditions. Respondents were more likely to believe that genetics contributes to adverse drug reactions and smoking-related illnesses than to infectious diseases and diseases resulting from exposure to environmental agents.

CONCLUSIONS

This study suggests that the public views genetic susceptibility as playing only a limited role in human disease induced by environmental factors. Increasing awareness of the role of genetic factors in these diseases will be necessary for translating gene discovery into effective personal and public health actions.

Attitudes of Health Care Trainees About Genetics and Disability: Issues of Access, Health Care Communication, and Decision Making

Prior studies suggest that knowledge and attitudes of health care professionals influence patient communication and medical decision-making. To study this dynamic in the context of genetic disability, we developed a survey on health professionals' attitudes regarding disability and genetic screening and pilot-tested it on a sample of medical students, residents, and genetic counseling students (N=85). Despite minimal experience with disability or genetics, most respondents reported feeling comfortable dealing with genetics (59%) and disability (75%). The majority felt that disability caused significant suffering for both the person (51%) and family (64%), and that research should be directed toward preventing genetic disability (62%). Similar to prior literature, perceived "Quality of Life" was most often based on degrees of physical and cognitive functioning, pain, and social support. However, differences were found between genetic counseling trainees and other medical trainees in their relative emphasis of social versus medical issues in questions of disability and genetic testing, and these response patterns were associated with differences in the groups' priorities for offering information about social resources. Respondents agreed that access to genetic testing and information is personal and that testing should be available upon request for oneself (68%) and to a lesser degree for one's fetus (55%) or child (41%). However, the same individuals frequently stated that society should regulate access to such technologies. Although most felt that the patient and professional should jointly make such decisions on a case-by-case basis, it was also seen as appropriate for the health care professional to occasionally decline genetic testing. It seems appropriate that training and experience influence knowledge and attitudes. Therefore, it is critical to document knowledge and attitudes of various health care providers and trainees, including differences between various specialties, to improve educational interventions geared to this area.

Application of population screening principles to genetic screening for adult-onset conditions

Recent advances in molecular genetics have highlighted the potential use of genetic testing to screen for adult-onset chronic diseases. Several issues must be addressed, however, before such tests can be recommended for population-based prevention programs. These issues include the adequacy of the scientific evidence, the balance of risks and benefits, the need for counseling and informed consent, and the costs and resources required. Ongoing assessment of the screening program and quality assurance of laboratory testing are also needed. This paper considers the application of general principles for mass screening to genetic testing for susceptibility to adult-onset chronic diseases. Evaluation of proposals for genetic screening in context of these principles reveals that needed evidence is often absent, particularly with respect to the predictive value of tests, efficacy of interventions, and social consequences of testing. The principles of population screening are developed into a framework for public health policy on genetic screening that has three stages: assessment of the screening test and interventions for those who test positive, including assessment of risks and costs, policy development, and program evaluation. Essential elements are identified, including evaluation of evidence and processes for consensus development and program evaluation. The proposed framework for public health policymaking outlined in this commentary, when combined with future efforts that involve an authoritative consensus process, may be useful for the evaluation and planning of genetic screening programs aimed at reducing morbidity and mortality from adult-onset chronic diseases.

[Apolipoprotein E gene polymorphism and risk of hypercholesterolemia: a case control study in a working population of Valencia]

BACKGROUND

The apolipoprotein E (apoE) gene is polymorphic with three common alleles (epsilon 2, epsilon 3, epsilon 4) whose allelic frequency and association with lipid levels varies from population to population. The aim of this study was to estimate the association between these genetic variants and the risk of hypercholesterolemia in a Mediterranean Spanish population.

PATIENTS AND METHODS

A case-control study in a working population from Valencia was carried out. A total of 330 cases (148 men and 182 women) with moderate hypercholesterolemia (total cholesterol > 200 mg/dl or with lipid lowering treatment) and age range 20 to 60 years, were identified. 330 normocholesterolemic controls matched by age and sex were selected. From all of them data of apoE genotype, body mass index, lipid and lipoprotein levels, socioeconomic and life-style variables were obtained.

RESULTS

The epsilon 2 allele frequency was statistically lower in cases (0.033) than in controls (0.086). The epsilon 4 allele frequency was higher in cases (0.115) than in controls (0.039). In the crude logistic regression analysis, the apoE polymorphism was related (p < 0.001) to the risk of hypercholesterolemia. After adjustment by age, body mass index, educational level, tobacco smoking, alcohol consumption and physical activity the epsilon 2 allele was associated with a lower risk of hypercholesterolemia (odds ratio [OR] = 0.36; 95% confidence interval (CI): 0.20-0.64), and the epsilon 4 allele was associated with a higher risk (OR = 3.04; 95% CI: 1.82-5.06).

CONCLUSIONS

The apoE genotype was significantly related to the risk of moderate hypercholesterolemia in the Mediterranean Spanish population.