Electronic Genetics Newsletter

Implementing a Preventive Ethics Strategy in the World of PreventiveMedicine

Prin. of  Modern GeneticsHuman Heredity

Shelly Cummings

Table 1). The author in an article in the December issue of Trends in Genetics proposes using a preventive ethical approach to prompt recognition to some of the ethical concerns that might accompany genetic research and testing for complex diseases.

Family studies are one of the most valuable tools used for assessing the natural history and inheritance patterns of complex disease. Family studies can reveal to study participants, however, information that was previously unknown (e.g. findings even not relevant to the study of interest), such as nonpaternity. The preventive ethics approach stresses the importance of ensuring that all participants in family studies fully understand that they could gain knowledge about themselves and their relatives that they might not want. It is at this point in the study that the participants give their informed and voluntary consent to participate. Informing even the most intelligent adults of the risks and benefits of participating in genetic family studies is very difficult because the risks are different than typical research studies. In research the risk is primarily physical, that is from drawing blood. In genetic family studies there are additional risks which could greatly impact upon the participant's life. For example, insurance companies might use genetic information to assign higher premiums or deny coverage for at-risk individuals. For these reasons, it is vital that investigators inform subjects about the risks and to inform them about relevant insurance and employment regulations, as well as reports of discrimination on the basis of genetic information. It should also be emphasized to study participants that the results of their involvement might not be of any benefit to them, but may help future generations and advance science.

The potential use of genetic tests for late-onset complex diseases such as Alzheimer's disease (AD) and Huntington disease (HD) poses some unique ethical dilemmas. Some authors fear that a positive test result for these conditions could result in severe depression and suicidal tendencies. In the case of HD a very elaborate procedure prior to undergoing genetic testing is implemented to anticipate and address these concerns. However, it is somewhat difficult to compare these two late-onset conditions to each other. Someone who is at risk for HD has most likely been surrounded by the condition as a result of having an affected family member and therefore it has become a part of their identity. Since we are just beginning to understand the genetics of AD, individuals who test positive for AD have not developed an AD-related identity. The psychological harm might be greater for someone who tests positive for AD than for someone who tests positive for HD.

As genetic research progresses, many diseases previously thought to be singularly caused by environmental factors or by genetic factors have, instead, been found to be caused by a complicated interaction between the two. In these multifactorial diseases, the individual has a genetic predisposition to the condition but an environmental exposure triggers the onset of that disease. In the field of behavioral genetics, researchers believe that some forms of addictive behavior may be genetically based. These findings question the ethical and legal responsibility of society regarding individuals who are substance abusers. If society is going to continue to focus on the genetics of diseases, particularly stigmatizing ones like substance abuse, attention must be paid to preventive interventions that address these factors.

The medical and scientific community, and society as a whole, must anticipate and take steps to prevent the potentially harmful effects that could result from various research and treatment strategies for complex disease. Understanding the intricate relationship between the environment and genetics will facilitate our conceptions of disease and of personal responsibility for health and behavior.

The genetics of behavior and multifactorial traits is found in chapter 16 in Human Heredity . The social and legal aspects of human genetics are considered in chapter 20 in Human Heredity . Mapping human disease genes are discussed in chapter 15 in Principles of Modern Genetics. The paper on the ethical problems raised by research on the genetics of complex diseases is: Parker, L., Ethical Concerns in the Research and Treatment of Complex Disease. Trends in Genetics December 1995:11(12).

Table 1

Genetic Testing For Complex Polygenic Diseases In The United States
Disease Number of People with Disease Number of Newly Diagnosed Cases per yr. (millions) Estimated Percent Due to Genetics Number of Potentially Diseased Probands (millions) Comments
Addictive Behavior 25% 6.7 25% 62
  1. Polygenic, but only 2 genes identified
  2. Curiosity is high - people want to know
  3. Important prevention strategies and early diagnosis
  4. Reduce guilt, shame, & denial
  5. Treatment available
  6. Genotype allows better targeting of treatment
Breast Cancer 12.3% .18 10% 1.65
Most BRCA1
  1. Penetrance is highly variable
  2. Chance of single gene only 1 in 10
  3. No acceptable specific treatment
Hypertension 20% 2 -3 Extremely difficult to estimate (20 - 75%) 15.6
  1. Many genes have been implicated & therefore the number of tests needed may be enormous
Alzheimer's 1.5% .3 - .4 10% due to single gene; 3 genes have been identified 0.4
  1. Many people do not want to know
  2. Treatment questionable
  3. Chance of single gene small - 1 in 10
  4. Not sure of penetrance
Colon Cancer 6% .14 10% 1.57
  1. Penetrance unknown
  2. Potential market small
Melanoma 6.5% .34 5 - 10% 1.70
  1. Potential market small

Send Feedback Heredity main menu Genetics main menu

| Send Feedback | Heredity main menu | Genetics main menu |
What's New | Order | Contact West | West College Home Page | West Educational Home Page | West Publishing Home Page
© Copyright 1996 WestPublishing