From genetics to genomics: using gene-based medicine to prevent disease and promote health in children

How should whole-genome sequencing be implemented in children? A consideration of the current limitations

In children, whole-genome sequencing (WGS) is envisioned as a tool to improve diagnosis of undiagnosed diseases and to improve population-based screening. Pilot applications have shown benefits: genomic information has been used as a diagnostic aid; pharmacogenomics can reduce medicine-related adverse events; advanced knowledge of the potential for later-onset disease can target tests and appropriate therapies. However, emerging technical, conceptual and ethical challenges may limit WGS from fulfilling the current vision for future applications. WGS platforms still struggle with reliability and accuracy. The role of the genome in long-term organismal function and disease is still being established. Ethical implications of WGS in both undiagnosed disease and population screening, particularly potential impacts of testing on children and their families are still unresolved.

Primary care and genetics and genomics

With the recent expansion of genetic science, its evolving translation to clinical medicine, and the growing number of available resources for genomics in primary care, the primary care provider must increasingly integrate genetics and genomics into daily practice. Because primary care medicine combines the treatment of acute illness with disease prevention and anticipatory guidance, the primary care provider is in an ideal position to evaluate and treat patients for genetic disease. The notion that genetic knowledge is only rarely needed will have to be replaced with a comprehensive approach that integrates "genetic thinking" into every patient encounter. Genomic competencies will need to be added to the primary care provider's repertoire; such competencies include prevention, assessment, evaluation, and diagnosis of genetic conditions; the ordering and interpreting of genetic tests; communication with families; appropriate referrals; and the management or comanagement of care. The process of deciding when to order genetic tests, what tests to order, and how to interpret the results is complex, and the tests and their results have specific risks and benefits, especially for pediatric patients. The longitudinal nature of primary pediatric care provides the opportunity to obtain and continually update the family history, which is the most powerful initial genetic "test." The ongoing provider-family relationship, coupled with the astounding number of advances in genetic and genomic testing, also necessitates a constant re-evaluation of past diagnosis or nondiagnosis.

Growing up in the genomic era: implications of whole-genome sequencing for children, families, and pediatric practice

Whole-genome sequencing (WGS) has advanced to a point where it is beginning to be integrated into pediatric practice. With little consensus on how to maximize the benefits of WGS for children, there is a growing need for focused efforts that connect researchers, clinicians, and families to chart a path forward. To illustrate relevant concerns, two contrasting applications of pediatric WGS are explored: clinical use with children who have undiagnosed conditions, and population-based screening. Specific challenges for health care services, policy development, and the well-being of children are discussed in light of current research. In the interest of ensuring evidence-based pediatric WGS, strategies are identified for advancing our understanding of what it means for children to grow up with WGS results guiding their health care.

Commentary: Children and predictive genomic testing: disease prevention, research protection, and our future

Genetic testing offered by direct-to-consumer companies-herein referred to as "predictive genomic testing"--has come under federal scrutiny. Critics claim testing yields uninterpretable and potentially harmful information. Supporters assert individuals have a right to this information, which could catalyze preventive health actions. Despite contentions that predictive genomic testing is a tool of primary disease prevention, little discussion has focused on its use with children. This partly stems from concerns expressed in existing professional guidelines about the potential for psychological and behavioral harm to children engendered by predictive genetic tests for Mendelian diseases. Conducting research to understand the actual benefits and harms is important for policy development and practice guidance and can be ethically justified within the pediatric regulatory framework of research that offers a prospect of direct benefit. Child health psychologists are well poised to contribute to this research effort, and promote the translation of genomic discoveries to improve pediatric medicine.

Genetic screening

Current approaches to genetic screening include newborn screening to identify infants who would benefit from early treatment, reproductive genetic screening to assist reproductive decision making, and family history assessment to identify individuals who would benefit from additional prevention measures. Although the traditional goal of screening is to identify early disease or risk in order to implement preventive therapy, genetic screening has always included an atypical element-information relevant to reproductive decisions. New technologies offer increasingly comprehensive identification of genetic conditions and susceptibilities. Tests based on these technologies are generating a different approach to screening that seeks to inform individuals about all of their genetic traits and susceptibilities for purposes that incorporate rapid diagnosis, family planning, and expediting of research, as well as the traditional screening goal of improving prevention. Use of these tests in population screening will increase the challenges already encountered in genetic screening programs, including false-positive and ambiguous test results, overdiagnosis, and incidental findings. Whether this approach is desirable requires further empiric research, but it also requires careful deliberation on the part of all concerned, including genomic researchers, clinicians, public health officials, health care payers, and especially those who will be the recipients of this novel screening approach.

Parents' attitudes toward pediatric genetic testing for common disease risk

OBJECTIVE

To describe parents' attitudes toward pediatric genetic testing for common, adult-onset health conditions and to identify factors underlying these attitudes.

PARTICIPANTS AND METHODS

Parents (n = 219) enrolled in a large, group-practice health plan were offered a "multiplex" genetic test for susceptibility to 8 common, adult-onset health conditions and completed an online survey assessing attitudes and beliefs about the risks and benefits of the test for their child, their willingness to consider having their child tested, and other psychosocial variables.

RESULTS

Parents viewed the benefits of pediatric testing to outweigh its risks (positive decisional balance) and were moderately interested in pediatric testing. Variables associated with positive decisional balance included greater interest in knowing about gene-health associations in their child, anticipation of less difficulty understanding their child's genetic health risks, and more positive emotional reactions to learning about their child's decreased health risks (adjusted R(2) = 0.33, P < .0001). Similarly, variables associated with greater parental willingness to test were being a mother (versus being a father), greater perceived risk of diseases in their child, greater interest in knowing about gene-health relationships in their child, anticipating less difficulty learning about their child's genetic health risks, anticipating more positive emotional reactions to learning about their child's decreased health risks, and positive decisional balance (adjusted R(2) = 0.57, P < .0001).

CONCLUSIONS

As genetic susceptibility testing for common, adult-onset health conditions proliferates, pediatricians should anticipate parents' interest in testing children and be prepared to facilitate informed decision making about such testing.

Ensuring the safe use of genomic medicine in children

Several clinical guidelines recommend that genetic testing in children be limited to tests with immediate clinical benefit. However, use of genome risk profiling will not likely meet this requirement, as the benefits are anticipated to be years away. Children who are at higher risk, though, will benefit the most from early initiation of treatment or interventions. The shift in benefit from immediate to long-term benefit warrants a reevaluation of the current practices of testing in children. In this commentary, the authors advocate the use of genomic risk profiling to identify children at increased risk who would benefit from early intervention, but recognize that its integration in clinical practice for this population will require a more nuanced approach to delivery and follow-up. In particular, the importance of counseling, context, consent, communication, and follow-up in the delivery of genomic risk testing to children and adolescents is highlighted.

Researchers' perceptions of the ethical implications of pharmacogenomics research with children

BACKGROUND

This paper presents the results of an exploratory qualitative study that assesses Canadian pediatric researchers' perceptions of a pre-selected group of ethical issues raised by pharmacogenomics research with children.

METHODS

As a pilot study, we conducted semi-structured telephone interviews with Canadian pediatric pharmacogenomic researchers. The interviews were guided by the following themes: (1) benefits and risks of inclusion, (2) the consent/assent process, and (3) the return of research results.

RESULTS

Issues about assent, consent, risks and benefits, as well as the communication of results were addressed by the respondents. Some issues, such as the unique vulnerability of children, the long term privacy concerns associated with biobanking, additional core elements that need to be discussed and included in the consent/assent forms, as well as the challenges of communicating research results in a pediatric research were not explicitly identified by the respondents.

CONCLUSION

Further consideration should be given to address the ethical challenges of including children in pharmacogenomics research. This exploratory study indicates that further guidance is needed if children are to be protected and yet benefit from such research.

The public's attitudes towards the use of genetic information for medical purposes and its related factors in Japan

OBJECTIVES

The aim of this study was to examine the knowledge of and attitudes on the use of genetic information for medical purposes among the general public of Japan and to identify how the knowledge and attitudes correlate with gender, age and related factors.

METHODS

A cross-sectional survey using a self-administered questionnaire was conducted from June to July 2004. Stratified random samples of 500 adults aged from 20 to 69 years, living in A-ward, Tokyo, Japan, were analyzed using a chi(2) test, t test and discriminant analysis (stepwise method).

RESULTS

Findings showed 'interested in the use of genetic information for medical research', 'useful for making effective use of medicine' and 'useful for determining disorders to which one may be susceptible in the future' as the three related factors that influenced discrimination in respondents' attitudes. Of these, 'interested in the use of genetic information for medical research' had a standardized discriminant coefficient of 0.946, indicating greatest relevance to discriminating respondents' attitudes. The factors 'useful for making effective use of medicine' and 'useful for determining disorders to which one may be susceptible in the future' exhibited the next highest discriminant relevance. There was no significant difference in gender and age.

CONCLUSIONS

This study clarified the knowledge of and attitudes on the use of genetic information for medical purposes among the general public of Japan.

Genetic diagnosis and testing in clinical practice

Genetic testing is defined as "the analysis of human DNA, RNA, chromosomes, proteins and certain metabolites in order to detect heritable disease-related genotypes, mutations, phenotypes or karyotypes for clinical purposes." This article focuses on diagnostic and predictive genetic testing. The latter includes presymptomatic testing, which identifies individuals who are expected to become ill in the future and predisposition testing, which identifies those who are at increased risk of becoming ill. Decisions regarding genetic testing must be based not only on the analytic accuracy, availability and cost of the test, but on the clinical utility as well, including the sensitivity, specificity and interpretability of results. Clinical information, including the medical and family history and the findings of the physical examination, is vital for the selection of appropriate diagnostic tests, as well as the interpretation of the results. Presymptomatic genetic testing is a very personal choice that should only be made after the patient has had sufficient counseling to develop an understanding of the risks and benefits of the test and is able to make an informed decision. The same principle applies to predisposition testing; however, additional factors, such as the probability of a positive result, the likelihood that the disease will actually develop in those with positive results, the effect on the management of the index patient, the effects on family members, the risk of false reassurance if the result is negative or the potential for loss of hope if it is positive, all contribute to the assessment of risk versus benefit. Clinical evaluation and counseling of the patient who is at risk for a genetic disorder are labor intensive but essential for the selection and interpretation of genetic tests.

Promoting children's health through understanding of genetics and genomics

PURPOSE

To describe the effects of genetics and genomics on children's health care.

ORGANIZING CONSTRUCT

The breakthroughs in the Human Genome Project have great potential for disease prediction, treatment, and prevention in the health care of children with chronic health conditions. Most childhood conditions based on a single gene are influenced by a complex interaction of genetic and environmental factors.

METHODS

A review of the literature was conducted to determine the most common childhood diseases linked to genetic causes.

FINDINGS

Two examples were selected to depict how a health professional would use genetic knowledge to provide holistic health promotion and disease prevention.

CONCLUSIONS

Knowledge of the interaction of the genetic profile coupled with a person's lifestyle, work environment, and family context provide a more holistic picture of a person's health profile. The clinical implications are that this knowledge will provide opportunities for health professionals to advise families on individualized treatment options or to tailor health promotion to future disease states based on genes and their interaction with the environment.