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In a recent JAMA issue devoted to
opportunities for medical research in the 21st century
(1),
Drs’ Collins and McKusick forecast a true integration of genetics into
the mainstream of medicine (2). They
project that the identification of genes followed by the development of
diagnostics (genetic tests) will lead to the development of
individualized preventive medicine (through targeted behavioral
modification and medical screening) and individualized drug treatments (pharmacogenomics).
They state, “Many primary care clinicians will become
practitioners of genomic medicine, having to explain complex statistical
risk information to healthy individuals who are seeking to enhance their
chances of staying well (2).”
In our excitement about genomic medicine
in the 21st century, we should not overlook the immense gap
between the scientific products of the Human Genome Project and the
kinds of beneficial application that Collins and McKusick describe. To
help close this gap, we see a crucial role for public health research,
especially in three areas (4).
1)
Epidemiologic research. Family
studies tend to overestimate the penetrance of genetic variants, as
shown in studies of BRCA1 and breast/ovarian cancers, and the
Apolipoprotein E-E4 allele and Alzheimer’s disease (3). There is an increasing need for population-based epidemiologic
studies to assess 1) prevalence of gene variants, 2) magnitude of
disease risk associated with gene variants, and 3) magnitude of disease
risk associated with gene-gene and gene-environment interactions (3).
The Atherosclerosis Risk in Communities Study
(5), the Framingham Heart Study (6), and the National Health and
Nutrition Examination Survey (7) are examples of large-scale
epidemiologic studies that are beginning to assess associations between
gene variants, environmental factors (e.g., smoking, physical activity,
diet), and the risk for common complex diseases. The scarcity of
population-based data for many newly discovered human gene variants will
make it difficult to develop appropriate health policy about the use of
genetic information.
2)
Policy and communication research.
To use genetic information to benefit health, we must address a
number of economic, social, ethical, and political issues, including the
information and communication needs of stakeholders. Public health
research to identify and analyze the implications of these types of
issues, together with epidemiologic data, provide the foundation for
developing effective policies about the appropriate use of genetic
information. Example: factor V Leiden is the most common genetic risk factor for venous
thrombosis, a leading cause of inpatient and maternal death (8,#9).
Policies concerning population screening for factor V Leiden
prior to prescribing oral contraceptives or during pregnancy should be
guided not only by clinical and epidemiologic data on risk-to-benefit
ratio, but also by an examination of possible personal and social
morbidity, overall economic cost, and public attitudes and opinions
(10).
3) Health services research. Assuring
that genetic testing is safe and effective requires health services
research. Questions include the following: How do the characteristics of
different health care systems (e.g., managed care) influence the
provision of genetic tests and subsequent clinical or preventive
services? Is it cost-effective to tailor interventions based on genetic
information? What factors
affect the understanding of complex genetic risk information and
compliance with proposed intervention strategies such as behavior
modification and medical screening?
Example: Colorectal
cancer is the second leading cause of death from cancer in the United
States; however, when it is detected at an early stage, the 5-year
survival rate approaches 90% (11). People who have a family history of colorectal cancer, an
indicator of possible genetic involvement, often develop the disease at
a younger age and may thus benefit from regular screening earlier than
otherwise recommended (12). Health
services researchers are investigating whether educating patients
directly about the importance of knowing one’s family history of
disease results in better compliance with screening guidelines than does
educating physicians (13).
In summary, while the new gene
discoveries provide emerging opportunities for medical research, public
health research is also needed to translate genetic discoveries into
personal and public health actions that improve health and prevent
disease. Population studies
in epidemiology, policy and communication sciences, and health services
research are crucial to make genomic medicine a reality in the 21st
century.
References
- Nathan DG, Fontanarosa PB, Wilson JD.
Opportunities for medical research in the 21st century. JAMA 2001;285:533-4.
- Collins FS, McKusick VA. Implications
of the Human Genome Project for medical science. JAMA 2001;285:540-4.
- Khoury MJ. Human genome epidemiology:
translating advances in
human genetics into population-based data for medicine and public
health. Genetics in Medicine 1999;1:71-4.
- Beskow LM, Khoury MJ, Baker T, et al.
The integration of genomics into public health research, policy, and
practice in the United States.
Community Genetics 2001 (in press).
- ARIC. Atherosclerosis Risk in
Communities Study description. [Online]. Available: http://www.cscc.unc.edu/aric/description.htm
(last accessed 5/2007)
- National Heart, Lung, and Blood
Institute. The Framingham Heart Study [Online]. Available: http://www.framingham.com/heart/index.htm
(last accessed 5/2007)
- National Center for Health Statistics.
National Health and Nutrition Examination Survey: NHANES III stored
biologic specimens. Dec 2000. [Online]. Available: http://www.cdc.gov/nchs/about/major/nhanes/coverpage.htm
(last accessed 5/2007)
- Price DT, Ridker PM. factor V Leiden
mutation and the risks for thromboembolic disease: a clinical
perspective. Ann Intern Med 1997;127:895-903.
- Ridker PM, Miletich JP, Hennekens CH,
Buring JE. Ethnic distribution of factor V Leiden in 4047 men and
women: implications for venous thromboembolism screening. JAMA 1997;277:1305-7.
- Vandenbroucke
JP, van der Meer FJM, Helmerhorst FM, Rosendaal FR. Factor V Leiden:
should we screen oral contraceptive users and pregnant women? Br Med
J 1996;313:127-30.
- National Cancer Institute. CancerNet:
PDQ: screening/detection-colorectal cancer-health professionals. Jan
2001. [Online]. Available: http://cancernet.nci.nih.gov/cancertopics/pdq/screening
(last accessed 5/2007)
- Winawer SJ, Fletcher RH, Miller L, et
al. Colorectal cancer screening: clinical guidelines and rationale.
Gastroenterology 1997;112:594-642.
- CDC. National Office of Public Health Genomics 1999 Highlights. Dec 2000. [Online]. Available: http://www.cdc.gov/genetics/about/hglt1999.htm.
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