Lesson 18, My Friend Linda
Author(s):
Sheila Matus
Overview of Lesson
- Courses for Which the Lesson Intended
- This lesson is intended for use in any biology course -
introductory or advanced - that includes a unit on genetics
or reproduction.
- Types of Teaching/Learning Activities Employed in this
Lesson
- Students read a story about a girl who grows up in a
family affected by the heritable, disabling and fatal medical
condition called Huntington's Disease. They then meet in
cooperative learning groups to define the meaning of several
relevant terms and to answer questions about ethical issues
related to the available genetic test for Huntington's
Disease. A classroom discussion is then held to explore the
differences among the group's responses to the questions
- Category that Best Describes this Lesson
- Social Issues.
- Ethics/Values Issues Raised by this Lesson
- General ethical issues related to modern biotechnology;
specific ethical issues related to testing for genetic
diseases; the ethical consequences of the disclosure of
genetic information.
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Lesson Plan
- In preparation for the lesson the students are given a
homework assignment requiring the written definition and
explanation of a series of terms related to the lesson.
- At the beginning of the class, students are given ten
minutes to read the brief introductory story, My Friend
Linda.
- The class is divided into cooperative learning groups of
three or four students each.
Working among themselves each group
- discusses and attempts to formulate a set of
definitions and descriptions for the terms in the
homework assignment.
- discusses and attempts to reach a consensus in
response to the discussion questions
- The teacher asks for volunteers among the reporters
for the learning groups to present definitions of the
assigned terms. With the help of other students the
definitions are discussed and, if necessary modified,
with the goal of producing a set of definitions that the
teacher and class find acceptable.
- The teacher then leads a class discussion based on
the questions, which is designed to expose the students
to the many unavoidable ethical issues that our society
faces as a result of the development of biotechnology and
its application to genetic testing.
Student Homework Assignment
Define and explain each of the following terms
- amniocentesis
- autosomal dominant inheritance
- tri-nucleotide
- ethical issue
- genetic testing
- allele
My Friend Linda
When I was ten years old, my best friend Linda's father
died. We knew he had been very sick, but Linda told us nothing
else about his illness. When you are ten, the death of someone
close to you is usually too frightening to talk about. Linda's
friends would never have dreamed of asking, What did your
daddy die of?
Although she moved to another city when we were both 13, I
kept in touch with Linda. When she was twenty she told me that
her brother Peter was ill. Peter was 31, married, and had a
two-year-old daughter. Over the next three years I learned from
Linda that his condition had gotten much worse and he had been
confined to a hospital. A year later Linda wrote to tell me
that he had died and that her unmarried sister Hope, then 33,
was showing early signs of the same disease that had taken the
lives of her father and brother.
Linda disclosed in that letter that her father, Peter, and
now Hope were victims of Huntington's Disease. She explained
that it is a genetic disease caused by an autosomal dominant
gene. Anyone who inherits the gene will suffer physical and
mental deterioration, usually beginning about age forty.
Symptoms from the most lethal form of the gene can sometimes
begin several years earlier. The disease begins by causing a
variety of physical symptoms. The victim loses muscular
control, soon becoming unable to walk normally or do tasks
requiring any coordinated motion. Speech becomes difficult and
then impossible. Within a few years serious mental disturbance
occurs followed inevitably by death. There is no cure, nor
effective treatment for the disease.
One purpose of Linda's letter was to seek my advice. She
faces a very difficult decision. Genetic research has
identified the form of the gene that causes Huntington's
disease. A test has been developed in which the gene is cloned
and DNA analysis can be done to determine if a person is
carrying the lethal allele. Linda is now 24 and she has fallen
in love. She knows there is a 50% chance that she inherited the
lethal gene from her father. The question she has asked me to
help her with is should she have the test done to find out
whether or not she is doomed to suffer the same fate as her
father, brother and sister?
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Discussion Questions
- Why might Linda not wish to be tested for the
Huntington's Disease gene?
- Do you think that Linda should be tested? Why?
- If Linda is tested and plans to be married, should she
tell her boyfriend about the results?
- If she decides not to be tested, should she explain to
her boyfriend that she has a 50% chance of having the lethal
gene, and that if she has it, any children she has will also
have a 50% chance of inheriting it from her?
- Should Linda's test results be available to health
insurance companies; to a potential employer; to the
government? Should anyone else be informed of the test
results without Linda's permission?
- Suppose Linda had an identical twin sister. Should that
sister have the right to know Linda's test results? Suppose
that sister does not want to be tested, and since it would be
difficult for Linda to hide either negative or positive test
results from her, should the sister have the right to prevent
Linda from being tested?
- Should being tested for the gene be a requirement for
anyone with a family history of Huntington's Disease?
- Suppose a cure, or effective treatment for Huntington's
Disease was discovered. Would this affect your answers to any
of the other questions?
- As you have seen in responding to these questions,
genetic testing involves decisions of an ethical nature that
have complicated possible effects on the person being tested,
family members and society. Since most people will not be
aware of all these issues, should genetic counseling be
required before an individual undergoes genetic testing? If
so, who should pay for it?
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Discussion
There is no doubt that biotechnology and the Human Genome
Project will continue to result in new technologies that will
become available to medical practitioners and to the public. It
is important that in addition to learning about the tremendous
potential benefits of this biotechnological revolution,
students become aware of the complex social and ethical issues
that will accompany this development.
In this lesson students learn that it is now possible for an
individual with a family history of Huntington's Disease, a
lethal inherited disease resulting from a genetic defect, to
have a test to find out if he or she has inherited the defect.
Since the disease is incurable and always fatal, the obvious
question is whether or not an individual is better off knowing
if the defect has indeed been inherited. Knowledge would be
helpful in many ways. If the results are negative it means the
individual can live a normal life without fearing an early,
horrible death. If the results are positive it can help an
individual prepare for the inevitable. An individual with the
inherited gene may decide not to have children, each of whom
would have a 50-50 chance of inheriting the lethal defect. On
the other hand an individual may prefer to live with the
uncertainty of not knowing rather than risk having to live with
the certainty that she or he is doomed. Question 6 points out
that the decision to have the test results in information that
can affect relatives as well as the individual in question.
Parents and children of an individual being tested, as well as
the more unusual case of an identical twin, could learn that
they are either definite or possible carriers of the defect
from the results obtained by a person who chooses to be tested.
This can clearly present thorny ethical problems for someone
who is considering being tested.
It is important to emphasize that serious ethical issues are
by no means confined to the case of genetic testing for a fatal
incurable disease. Genetic testing of any sort is associated
with serious potential consequences that most people are not
aware of. In many cases an individual is advised to see a
genetic counselor before making a decision about whether to be
tested. It has been suggested by some of the people who have
studied this issue that such counseling should be made
mandatory. Before any action could be taken on such a
suggestion it would be necessary to define what constitutes
adequate counseling. At present, genetic testing and counseling
are expensive and are not financially feasible for the majority
of people. This raises a general ethical concern about how a
democratic society can assure fair access to present and future
expensive biomedical technological procedures.
Sheila Matus, Oyster Bay High
School, Oyster Bay, Long Island, NY.