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Genetic testing can be divided into two basic types:
diagnostic and predictive. Diagnostic tests involve
determining the cause of a disease in a patient with
symptoms, much the same as standard blood tests or x-rays
would be used. Predictive tests are those in which a
person is found to be at increased risk for a disorder,
but no symptoms of the disorder are present. There are
fundamental differences in the ethical and procedural
issues involved in using these different forms of testing.
Diagnostic genetic testing for heritable disorders
has been in common medical practice for more than thirty
years, well before the advent of DNA technology. In
fact, some tests still rely on non-DNA methodologies.
The most well known example is the study of hemoglobin
to diagnose hereditary blood disorders, such as sickle
cell disease and thallasemias. Even though DNA testing
is available for these diseases, electrophoretic analysis
of hemoglobin is still the method of choice in most
situations.
Generally, patient consent specifically for genetically
based diagnostic tests are not required. It is fundamental
to management of a patient for the physician to know
the nature of the disease in question. Predictive testing
is a much more complex matter. As the availability of
predictive testing for various medical conditions continues
to grow, the question as to whether these tests should
be performed has stirred a great deal of debate. Among
the myriad of questions, one is at the core: Is it better
to know or not to know that you have the genetic makeup
to develop a disease or condition?
On the affirmative side of the debate, genetic testing
offers people an opportunity to take unprecedented proactive
measures to safeguard their health and even prolong
their lives. The Adult Onset Genetic Disease Program
at University Hospital tests only for genetic conditions
for which there is a treatment or treatments, and that
is an important distinction to make. Testing without
viable treatment options opens a Pandora’s box
of problems, such as anxiety or depression.
If a genetic test is desired, it should be done with
the assistance and support of certified genetic counselors.
"Mail order” genetic testing services are
available, but getting a generic results form is no
match to having a trained genetics counselor discuss
all aspects of testing and the results face to face.
When the results are positive, a genetic counselor presents
the options for treatment in an objective manner. Receiving
tests results can be an emotional experience, even if
the test shows someone is not predisposed to developing
a condition. A genetic counselor can also help patients
deal with the emotions or refer them to a mental health
professional for additional support.
Privacy and discrimination issues are at the forefront
of any discussion involving genetic testing. Many states,
including New Jersey, have laws that protect the privacy
of people who undergo genetic testing. The New Jersey
Genetic Privacy Act states that test results cannot
be released to anyone without specific, written consent
from the patient and prohibits discrimination by insurance
companies.
When it comes to testing children, it’s generally
agreed that testing for late onset diseases should be
deferred until they can make their own decisions. An
exception is when the disease can present during childhood
or adolescence, such as is the case with familial adenomatous
polyposis, a type of heritable colon cancer.
Genetic testing can provide important information,
but whether or not to be tested is a matter for an individual
to decide after being fully informed about all of the
implications: what a positive and a negative result
actually means, and what the consequences of the test
results have for family members who may or may not want
to know.
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Ethics
of Genetic Testing
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