Chapter 1, Problem 1CS

Mary and Marcie. identical twins, go to the same internist who is also a faculty member at a major medical center. At their last visit, they each received a brochure describing a genetics research program recently launched by the hospital and its affiliated university. Researchers were asking for volunteers to fill out a questionnaire and a consent form, donate a blood sample, and have their medical records encoded and transferred to a database. The goal was to enroll 100,000 participants, and the brochure noted that over 10,000 people had already agreed to participate.

The blood sample would be used to extract DNA. which would be encoded with the same number as the medical records. This DNA would be used to search for genes associated with conditions such as arthritis, diabetes, and Alzheimer disease. The idea is that researchers interested in studying arthritis would use the medical records to identify which participants have the condition and then use DNA from those individuals to find genetic similarities that are not present in participants who do not have arthritis. The genetic similarities help identify regions of the genome that contain genes associated with arthritis. These regions can then be studied in detail to identify and isolate genes that may be associated with arthritis and other inflammatory disorders.

In exchange for enrolling, participants would be informed about any genetic conditions or predispositions to genetic disease they carry and would receive free access to testing. After discussing the brochure. Mary decided to enroll, but Marcie decided she did not want to do so. She said she did not want to know what diseases she may develop or which disease genes she may carry.

At their next annual visit. Mary’s internist told her that because her questionnaire indicated that some relatives had Alzheimer disease, her DNA was used in a study to identify risk genes. He said she had been identified as a carrier of a gene that greatly increased the likelihood that she would develop Alzheimer disease. The physician told her that age was the greatest risk factor, and while it was not 100% certain she would become a victim of Alzheimer disease, the gene she carries is a factor in 20–25% of all cases. Mary asked if there was anything she could do about these findings. The internist told her that exercise, controlling blood pressure and cholesterol levels, as well as participating in mentally challenging activities such as reading or playing a musical instrument may all help reduce her chances of developing this disease. Mary then asked if Marcie was going to be told about Mary’s genetic risk, and the internist said that he would not tell her.

For the next few days. Mary was conflicted about the situation. Marcie was an Identical twin, and If Mary carried a gene predisposing her to Alzheimer disease. Marcie must carry the same gene. Marcie did not exercise with Mary, had high blood pressure, and little interest in reading or social activities. Mary did not know whether she should tell Marcie.

If you were advising Mary, what would you say? Should she tell Marcie about the risk? Should she not tell her, but instead try to get Marcie to exercise and be more social? Should Mary ask their internist to talk with Marcie about this?

Summary Introduction

To explain: The suggestions an individual would give to Mary in the given situation.

Introduction: Alzheimer is a genetic disease that leads to permanent dementia (memory loss) in old ages. It is one of the most common forms of dementia in elderly people. Symptoms of Alzheimer disease are somewhat different from dementia caused due to other reasons. It is a genetic disorder that is caused by genetic mutations of some genes that are associated with human memory. These genetic mutations cause structural as well as cellular changes in the brain and its activities leading to reduced capability of memorizing things and effect on daily life activities.

Explanation of Solution

In the case as of the twin sisters Mary and Marcie, a person would suggest similar things that the physician suggested to Mary. She would be told to have a healthy body with regular exercise and balanced diet. For a person who is likely to become a patient of the known disease, it is very beneficial to adopt the habits that would delay or reduce the severity of the disease. For Alzheimer disease, it is very important to keep control of the blood pressure and the cholesterol level in the body.

Along with this, Mary would also be suggested to talk to her sister to get tested for the disease. Instead of taking the stress of the upcoming disease, it would be more beneficial to adopt the necessary measures that can reduce or delay the know disease.

Summary Introduction

To explain: Whether Mary should inform Marcie about the risk they both have or not.

Explanation of Solution

Upon getting to know about the risk of Alzheimer disease that both these twin sisters carry, Mary should definitely inform Marcie about it. She should make her aware of the upcoming disease and the possible ways for delaying and reducing the severity of the upcoming disease.

Summary Introduction

To explain: Whether Mary should not inform Marcie about the risk and try to get her to exercise and be more social.

Explanation of Solution

Although Mary should inform her sister Marcie about the risk of Alzheimer disease that she might be carrying, but she can also be motivated to be involved in more exercise and social activities. This can help her to delay the onset of the disease. Marcie can be made to understand the complete situation and helped in moving towards a healthier lifestyle.

Summary Introduction

To explain: Whether Mary should ask her internist to talk with Marcie about the situation or not.

Explanation of Solution

Mary can definitely ask her internist to talk to her sister Marcie regarding the genetic risk that Marcie would be carrying. She can ask the physician to make Marcie understand about the disease and the measures that can be adopted to delay the onset of the disease.