A Right to Her Genes

Case Study;
But, doctor, what should I do?”
Michelle was sitting in her OB-GYN’s office, having just confronted him with the dilemma she was
facing.
“My mother died of breast cancer when I was little and now I find out that her mother, my grandmother,
has bone cancer and my grandmother’s brother and my grandfather both have lung cancer. My mother
was 40 when she died and I’m almost that now myself. Should I have my breasts removed to prevent me
from getting breast cancer?”
The doctor tried to calm her down and clarify the family tree. As far as Michelle knew, her mother was
the oldest of four girls and two boys in the family and the only one to have cancer. In fact, her
grandfather also had a brother and two sisters, and none of them showed any signs of cancer.
“It’s not strong enough evidence to suggest you should remove your breasts,” the doctor said. “Actually,
breast cancer susceptibility is not linked to lung cancer. Lung cancer, especially, is usually linked to
environmental factors, like smoking or exposure to asbestos. Does your father smoke?” the doctor
asked.
“Yes,” Michelle replied. “But I don’t want to get cancer and have my two little boys watch me die the
way I did with my mother.”
The doctor suggested Michelle gather more information about her family tree and then come back and
he would contact a genetic counselor about the possibility of genetic testing.
A month later, Michelle went to see her doctor again after having talked with her grandmother
extensively about the family. She had uncovered two very interesting family facts. First, the man she
thought was her mother’s father was not her biological grandfather, but his brother. Her real grandfather
had no history of cancer. Second, Michelle found out her mother had an estranged older sister, Anne,
who had recently been diagnosed with ovarian cancer. The doctor now felt the family connection was
strong enough to advise Michelle that there was a possibility of a cancer gene linkage in the family.
A Right to Her Genes
by
Susannah Gal
Department of Biological Sciences
State University of New York at Binghamton
and
Jessie W. Klein
Science Department
Middlesex Community College
The doctor contacted Laura, a genetic counselor in the area, and found out that the most likely
candidates were the breast cancer genes BRCA1 and BRCA2. Mutations in one of these two genes are
found in 90% of tumors from breast and ovarian cancer. Women with hereditary mutations in one of
these genes are 30 times more likely to develop breast cancer by age 50, while men have a three times
higher risk of developing prostate or colon cancer if they inherit this mutation. The genetic counselor
clarified that a variety of studies have suggested that mutations in BRCA1 are more often linked with
breast and ovarian cancer, while mutations in BRCA2 are most often linked only with breast cancer. The
fact that Michelle’s grandmother, the mother of both affected women, had bone cancer and not breast or
ovarian cancer might be the result of a metastasis from the original site of the tumor in the breast. Thus,
Laura felt this family was a candidate for a BRCA1 mutation.
With Michelle’s consent, the doctor arranged to have the breast biopsy sample from her mother sent to a
DNA testing facility, Myriad Genetics in Salt Lake City, Utah. A month later they found out that the
sample was a poor one, making it difficult to get any information. The testing facility thought that the
sample might not have been prepared or stored properly and thus the DNA in it was degraded beyond
usefulness. So, there was no data to indicate that Michelle’s mother’s cancer was due to a mutation in
BRCA1. No other samples existed of Michelle’s mother’s tumor or other tissue from which they could
do another analysis.
Michelle’s doctor contacted Laura, the genetic counselor, to discuss the case. Laura felt that in order to
make any assessment, a DNA sample from an individual with cancer was needed. This sample could
then be used as a comparison for the sample, namely Michelle’s, with unknown cancer risk. If the DNA
from an individual with cancer showed a mutation in the BRCA1 gene, Laura explained, then they
would look for the same mutation in Michelle’s DNA. Ideally, the mother’s DNA would have provided
them with this information, but without it, a DNA sample from another close relative with cancer was
essential. Otherwise, they wouldn’t be able to be certain that a DNA change in Michelle’s BRCA1 gene
was necessarily linked to cancer. DNA from the estranged, cancer-carrying aunt would be very useful
and could be obtained from a sample of her blood.
Laura had a lengthy conversation with Michelle in which they went over Michelle’s complicated family
situation. Laura then wrote a letter to Anne, the aunt who lived in a remote town two hours away, in
which she explained the process and asked for her informed consent to give a blood sample to get DNA.
After two weeks had gone by with no reply, Laura tried contacting Michelle’s aunt a second time.
Again, she received no reply. After the third time, Laura finally got the aunt on the phone. Anne
reluctantly agreed to meet with Laura for coffee—not in her home, but in a restaurant in her small
town—and as long as Laura paid for it.
Laura met Anne at the restaurant at the appointed hour. Anne was accompanied by a younger woman
who turned out to be her daughter. The daughter read the menu for her mother and Laura suspected that
the older woman was illiterate.
After introducing herself, Laura said: “I’m here representing your niece, who would like to arrange to
get some information from you to help her decide if she has a cancer gene.”
Anne looked confused. “What’s a gene?” she asked.
Laura explained: “Our bodies are made up of small parts called cells that contain a substance called
DNA. DNA is the blueprint for our cells and controls everything about us. DNA is the same in all your
cells. It is passed from one generation to the next, provided from both mother and father at fertilization.
So, the DNA found in Michelle should be similar to your DNA, since the two of you are related.
2
Changes in your family’s DNA may have made several of its members more susceptible to cancer and
would explain why several of you have gotten the disease. This would include your sister, Michelle’s
mother, who died from breast cancer. Michelle would like to know if there is such a change in your
DNA and also in her own DNA. If there is such a mutation, Michelle might then decide to remove either
her breasts or her ovaries to prevent her from getting cancer. Michelle would like you to give a blood
sample at your doctor’s so that DNA can be isolated and the gene sequence determined.”
Anne was silent for a moment and then asked Laura, “Who would pay for this? I haven’t got any
money.”
“I don’t know that yet. Who covers your medical bills?” asked Laura.
“My medical bills are covered by Medicaid,” Anne said.
Laura knew that the BRCA1 test costs in the neighborhood of $2500 for the complete information about
this gene and that Medicaid would not pay for it.
Anne’s daughter interjected belligerently, “Why are you doing this, Mom, when they ignored you for so
many years and haven’t given us any money since you left?”

1. Create a family tree using standard symbols for the people mentioned in the case and include
   some designation to indicate those affected with cancer.
2. What part of the blood sample would be used for the DNA analysis and why?
3. What techniques can be used to determine whether Anne’s DNA has a mutation in the BRCA1
   gene?
4. Why might the degradation of the DNA from Michelle’s mother make the information obtained
   unusable? Are there other approaches one could use to get around that problem?
5. What do each of the people in this scenario want to get out of this situation?
6. What problems do you foresee with the different agendas—the different needs—of the people
   involved in this case?
7. What are ways that one could solve these problems?