Genetic testing: a double-edged sword for our physical and mental health

Thanks to the great improvements in genetics, including the completion of DNA sequencing and the recording of thousands of variations in the DNA sequence that can predispose to syndromes or diseases (read here for further details), genetic testing became more and more popular. The principle of genetic testing is very simple: a DNA sample is taken from a person (usually from saliva), and analyzed to verify the presence of any mutation that predisposes for a disease. This can be very useful in preventing the disease, when possible, or to prepare to cure it in the best way. It sounds easy and useful, right? But what exactly is the information that we obtain from a genetic testing? Is it really only a positive/negative test? The answer is no. In fact, this question raises the issue about the ethics of genetic testing. Some basic guidelines were provided by the World Health Organization in 1998:

“Every genetic test should be offered in such a way that individuals and families are free to refuse or accept according to their wishes and moral beliefs. All testing should be preceded by adequate information about the purpose and possible outcomes of the test and potential choices that might arise. Children should only be tested when it is for the purpose of better medical care.”

Who should undergo a genetic test?

The shortest answer is “anyone who is at risk for a disease”, but obviously the situation is different for adults and children, with the latter not being able to decide independently if to undergo the test or not. About adults, a genetic test is recommended if they are at risk to develop some hereditary disease, although the willingness in asymptomatic adults at risk, vary a lot. Willingness to undergo a test increases if it gives the possibility to prevent the disease or at least to mitigate its course. Instead, for incurable diseases such as Huntington disease (a degenerative neuropsychiatric disorder), less than 20% of all those at risk do the test, although it has been available for more than 25 years. About children, it is difficult to say if a test can be beneficial compared to the same test done in adulthood. Therefore, for genetic conditions that will not appear until adulthood, the test should be postponed until the child is competent to decide whether he/she wants the information.

Psychological concerns: I do the test, and then?

One person chooses to undergo a genetic test. How will this person deal with the result? Several studies tried to give an answer, and the outcome is not as obvious as you may expect. For example, people at risk for Huntington disease are not devastated after a positive result; conversely, in some cases, a person at risk who receives a negative result can show an increasing psychological stress. Sometimes it may be better not to know the result of a genetic test, because the result can affect relational bonds and family dynamics. A positive test may confer a psychological impact on both the child tested and the parents who may feel guilty.

Social concern: who will know about the result of my test?

A person who undergoes genetic testing should be the only one with the right to own the information, and to decide whether third parties are allowed to access the data. Privacy is a complex issue nowadays. In most cases, when we accept websites’ privacy conditions, we don’t even read or understand what we are signing, or agreeing with. Generally it is about data and traffic information that the website records and sells to third parties (this results with targeted ads). With our genetic data, this must not happen. No one should force you to sign some privacy agreement without you being fully aware of what you agree with, and no one should exploit your data without your consent. No debate about it. Few decades ago, people were discriminated because of the outcome of genetic testing. During the 1970s, some US states forced African-American population to undergo genetic testing for sickle cell anemia, and were subsequently discriminated against on the basis of carrier status.

Let’s now see more in detail the informed consent.

Informed consent is the process to get permission to begin a healthcare-related procedure, including genetic testing. Informed consent is based on the principles of right to autonomy and self-determination. However, autonomy is never an individual-related issue, because it is influenced by relational forces, especially if the subject of the test is a child. It is impossible to separate the interests of the family from the interests of the child, therefore appropriate information and counselling about testing issues are essential. For example, it is important to distinguish the need for parents to know whether their child has inherited the disease-causing gene from the need for the child to know. When possible, the decision should be taken with the child. A 4-years-old child is able to understand some concepts of inheritance, but concepts about disease might be taken with a feeling of guilt. Health-related procedure should be faced with a child older than 7-years-old, although full understanding is not achieved until adolescence.

What if parents insist to subject their healthy child to genetic testing?

If after full counselling about ethical and social concerns parents still want to do a test on their not-at-risk child, the best solution for the child should be considered. The benefits and potential harms of testing for the child should be weighed, and if harms are too relevant, the healthcare provider should not feel obligated to perform the test. Parents do not have authority over non-therapeutic interventions, including genetic testing, but only on their children’s therapeutic treatments.

What about adopted children?

Adopting agencies have the duty to provide all the health-related information about a child, including genetic testing if present, but they are not obliged to subject a child to genetic testing if potential adoptive parents are asking for it. Once more, the child’s best interests have to be protected.

Is that all?

Not really. A genetic testing can be done not only to verify the predisposition to a disease. One of the main purposes that pushes people to do a genetic test is to learn about ancestry. Other genetic companies sell specific diets and fitness plans, improved on the basis of specific genetic tests. Again, some companies sell tests for kids to learn about the potentialities (i.e.: in sports). Are these tests worth? In my opinion, I would say no for two reasons. First, remember the privacy issue (these companies will own and store all your most private information, much more than what Apple or Microsoft can get from your internet history). Second, a genetic test is not mathematics. No genetic test can tell with accuracy what the best diet is for you or what career your kid should take. If you are planning to do a genetic test with this purposes, better eat what you like and let your child play how he/she wants. Genetic testing is not a game, and should not be intended as a tool to satisfy your curiosity. For that, I recommend palmistry or any of the thousands of tests you can find on the internet.

References

Guidelines for genetic testing of healthy children. Paediatr Child Health. 2003; 8(1):42-52.

Huggins M, Bloch M, Wiggins S, Adam S, Suchowersky O, Trew M, Klimek M, Greenberg CR, Eleff M, Thompson LP. Predictive testing for Huntington disease in Canada: adverse effects and unexpected results in those receiving a decreased risk. Am J Med Genet. 1992 Feb 15; 42(4):508-15.

Wiggins S, Whyte P, Huggins M, Adam S, Theilmann J, Bloch M, Sheps SB, Schechter MT, Hayden MR. The psychological consequences of predictive testing for Huntington’s disease. Canadian Collaborative Study of Predictive Testing. N Engl J Med. 1992 Nov 12; 327(20):1401-5.

Fanos JH, Johnson JP. Barriers to carrier testing for adult cystic fibrosis sibs: the importance of not knowing. Am J Med Genet. 1995 Oct 23; 59(1):85-91.

Florencio PS. Genetics, parenting, and children’s rights in the twenty-first century. McGill Law J. 2000 May; 45(2):527-58.

World Health Organization Proposed International Guidelines on Ethical Issues in Medical Genetics and Genetic Services Geneva: World Health Organization; 1998. <http://www.who.int/ncd/hgn/hgnethic.htm> (Version current at December 11, 2002).

Meiser B, Dunn S. Psychological impact of genetic testing for Huntington’s disease: an update of the literature. J Neurol Neurosurg Psychiatry. 2000 Nov; 69(5):574-8.

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