Chapter 6: Genetics and Genomics
A nurse obtains health histories when admitting clients to a medical-surgical unit. With which client would the nurse discuss predisposition genetic testing? a. Middle-age woman whose mother died at age 48 of breast cancer. b. Young man who has all the symptoms of rheumatoid arthritis. c. Pregnant woman whose father has sickle cell disease. d. Middle-age man of Eastern European Jewish ancestry.
ANS: A A client with a family history of breast cancer would be provided information about predisposition testing. Predisposition testing would be discussed with clients who are at high risk of hereditary breast, ovarian, and colorectal cancers so that the client can engage in heightened screening activities or interventions that reduce risk. The client with symptoms of rheumatoid arthritis would be given information about symptomatic diagnostic testing. The client with a familial history of sickle cell disease and the client who is of Eastern European Jewish ancestry would be given information about carrier testing.
A nurse cares for a pregnant client who has a family history of sickle cell disease. The client is unsure if she wants to participate in genetic testing. What action would the nurse take? a. Provide information about the risks and benefits of genetic testing. b. Empathize with the client and share a personal story about a hereditary disorder. c. Teach the client that early detection can minimize transmission to the fetus. d. Advocate for the client and her baby by encouraging genetic testing.
ANS: A Genetic counseling is to be nondirective. The nurse would provide as much information as possible about the risks and benefits but would not influence the patient's decision to test or not test. Once the client has made a decision, the nurse would support the client in that decision. Carrier testing will determine if a client without symptoms has an allele for a recessive disorder that could be transmitted to his or her child. Genetic testing will not minimize transmission of the disorder.
A primary health care provider prescribes genetic testing for a client who has a family history of colorectal cancer. Which action would the nurse take before scheduling the client for the procedure? a. Confirm that informed consent was obtained and placed on the patient's chart. b. Provide genetic counseling to the client and the patient's family members. c. Assess if the client is prepared for the risk of psychological side effects. d. Respect the patient's right not to share the results of the genetic test.
ANS: A Informed consent is required before genetic testing. The person tested is the one who gives consent. An advanced practice provider would explain the procedure and provide genetic counseling. Although the client would be prepared for the risk of psychological side effects and the patient's rights would be respected, the procedure cannot occur without informed consent.
A nurse cares for a client who recently completed genetic testing that revealed that she has a BRCA1 gene mutation. What actions would the nurse take next? (Select all that apply.) a. Assess the patient's response to the test results. b. Assist the client to make a plan for prevention and risk reduction. c. Disclose the information to the medical insurance company. d. Discuss potential risks for other members of her family. e. Encourage support by sharing the results with family members. f. Recommend the client complete weekly breast self-examinations.
ANS: A, B, D The medical-surgical nurse can assess the patient's response to the test results, discuss potential risks for other family members, encourage genetic counseling, and assist the client to make a plan for prevention, risk reduction, and early detection. For some positive genetic test results, such as having a BRCA1 gene mutation, the risk for developing breast cancer is high but is not a certainty. Because the risk is high, the client would have a plan for prevention and risk reduction. One form of prevention is early detection. Breast self-examinations may be helpful when performed monthly, but those performed every week may not be useful, especially around the time of menses. A client who tests positive for a BRCA1 mutation would have at least yearly mammograms and ovarian ultrasounds to detect cancer at an early stage, when it is more easily cured. Owing to confidentiality, the nurse would never reveal any information about a client to an insurance company or family members without the patient's permission.
A nurse cares for a client who is scheduled for genetic testing. What actions would the nurse include in the patient's pretesting assessment? (Select all that apply.) a. Assess the client's understanding of the genetic test. b. Obtain physical assessment data relevant to the at-risk disorder. c. Discuss prevention, early detection, and treatment options. d. Assess the client's perception of the test results. e. Discuss client rights and obligations regarding disclosure of information.
ANS: A, B, E During the pretesting assessment, the nurse would evaluate the patient's understanding of the genetic test being sought and obtain relevant information including physical assessment, family history, psychosocial status, and social support. The nurse would also discuss client rights and obligations regarding disclosure of information, risks and benefits of testing, and testing options. Discussion of prevention, early detection and treatment options, and an assessment of the patient's perception of the test results would occur after genetic testing is complete.
A nurse teaches clients about patterns of inheritance for genetic disorders among adults. Which disorders have an autosomal dominant pattern of inheritance? (Select all that apply.) a. Breast cancer b. Alzheimer disease c. Hemophilia d. Huntington disease e. Marfan syndrome f. Cystic fibrosis
ANS: A, D, E Breast cancer, Huntington disease, and Marfan syndrome have an autosomal dominant pattern of inheritance. Alzheimer disease is a complex disorder with familial clustering, hemophilia is a sex-linked recessive disorder, and cystic fibrosis has an autosomal recessive pattern of inheritance.
A nurse consults a genetic counselor for a client whose mother has Huntington disease and is considering genetic testing. The client states, "I know I want this test. Why do I need to see a counselor?" How would the nurse respond? a. "The counselor will advise you on whether you can have children or need to adopt." b. "Genetic testing can be a stressful experience. Counseling can provide support and education throughout the process." c. "There is no cure for this disease. The counselor will determine if there is any benefit to genetic testing." d. "Genetic testing is expensive. The counselor will advocate for you and help you obtain financial support."
ANS: B Genetic testing is a stressful experience, and clients would be provided with support, education, and assistance with coping. Genetic testing would be performed only after genetic counseling has occurred. The client has the right to decide whether to have children or to participate in genetic testing. Nursing staff would provide both benefits and risks to genetic testing so that the client can make an informed decision. Financial support is not part of genetic counseling.
A nurse is educating a client about genetic screening. The client asks why red-green color blindness, an X-linked recessive disorder noted in some family members, is expressed more frequently in males than females. How would the nurse respond? a. "Females have a decreased penetrance rate for this gene mutation and are therefore less likely to express the trait." b. "Females have two X chromosomes and one is always inactive. This inactivity decreases the effect of the gene." c. "The incidence of X-linked recessive disorders is higher in males because they do not have a second X chromosome to balance expression of the gene." d. "Males have only one X chromosome, which allows the X-linked recessive disorder to be transmitted from father to son."
ANS: C Because the number of X chromosomes in males and females is not the same (1:2), the number of X-linked chromosome genes in the two genders is also unequal. Males have only one X chromosome, a condition called hemizygosity, for any gene on the X chromosome. As a result, X-linked recessive genes have a dominant expressive pattern of inheritance in males and a recessive expressive pattern of inheritance in females. This difference in expression occurs because males do not have a second X chromosome to balance the expression of any recessive gene on the first X chromosome. It is incorrect to say that one X chromosome of a pair is always inactive in females, or that females have a decreased penetrance rate for this gene mutation. X-linked recessive disorders cannot be transmitted from father to son, but the trait is transmitted from father to all daughters who will be carriers.
A nurse cares for a client who recently completed genetic testing and received a negative result. The client states, "I feel guilty because so many of my family members are carriers of this disease and I am not." How would the nurse respond? a. "You are not genetically predisposed for this disease but you could still become ill. Let's discuss a plan for prevention." b. "Since many of your family members are carriers, you would undergo further testing to verify the results are accurate." c. "We usually encourage clients to participate in counseling after receiving test results. Can I arrange this for you?" d. "It is normal to feel this way. I think you would share this news with your family so that they can support you."
ANS: C Clients who have negative genetic test results need counseling and support. Some clients may have an unrealistic view of what a negative result means for their general health. Others may feel guilty that they were "spared" when some family members were not. The client will not be symptomatic if he or she is not a carrier of the disease. A second round of testing is not recommended, because false negatives are rare with this type of testing. It is the client's choice to reveal test results to family members; the nurse would not encourage this.
A nurse cares for a client who has a specific mutation in the a1AT (alpha1-antitrypsin) gene. What action would the nurse take? a. Teach the client to perform monthly breast self-examinations and schedule an annual mammogram. b. Support the client when sharing test results and encourages family members to be screened for cancer. c. Advise the client to limit exposure to secondhand smoke and other respiratory irritants. d. Obtain a complete health history to identify other genetic problems associated with this gene mutation.
ANS: C The a1AT gene mutation increases risk for developing early-onset emphysema. Clients would be advised to limit exposure to smoke and other respiratory irritants as a means of decreasing environmental influences that may aggravate an early onset of emphysema. This gene mutation does not promote cancer, nor does it occur with other identified genetic problems. The BRCA1 gene mutation gives the client a higher risk for developing breast cancer.
A client is typed and crossmatched for a unit of blood. Which statement by the nurse indicates a need for further genetic education? a. "Blood type is formed from three gene alleles: A, B, and O." b. "Each blood type allele is inherited from the mother or the father." c. "If the patient's blood type is AB, then the client is homozygous for that trait." d. "If the client has dominant and recessive alleles, the dominant will be expressed."
ANS: C There are three possible gene alleles for blood type: A, B, and O, which are inherited from the parents. If both a dominant and recessive gene allele are present, the dominant one is always expressed. Blood type AB is a heterozygous type, meaning the two alleles are different. The nurse stating that type AB is homozygous needs further education.
A nurse cares for a client who has a genetic mutation that increases the risk for colon cancer. The client states that he/she does not want any family to know about this result. How would the nurse respond? a. "It is required by law that you inform your siblings and children about this result so that they also can be tested and monitored for colon cancer." b. "It is not necessary to tell your siblings because they are adults, but you would tell your children so that they can be tested before they decide to have children of their own." c. "It is not required that you tell anyone about this result. However, your siblings and children may also be at risk for colon cancer and this information might help them." d. "It is your decision to determine with whom, if anyone, you discuss this test result. However, you may be held liable if you withhold this information and a family member gets colon cancer."
ANS: C This situation represents an ethical dilemma. It is the client's decision whether to disclose the information. However, the information can affect others in the client's family. The law does not require the client to tell family members about the results, nor can the client be held liable for not telling them. The nurse may consider it ethically correct for clients to tell family members so that they can take action to prevent the development of cancer, but the nurse must respect the client's decision.
A nurse completes pedigree charts for clients at a community health center. Which diagnoses would the nurse refer for carrier genetic testing? (Select all that apply.) a. Breast cancer b. Colorectal cancer c. Cystic fibrosis d. Hemophilia e. Huntington disease f. Sickle cell disease
ANS: C, D, F Of the disease processes listed, the ones that would make the client a candidate for carrier genetic testing would be hemophilia, sickle cell disease, and cystic fibrosis. Although Huntington disease, breast cancer, and colorectal cancer all have genetic components, there is no evidence that carrier genetic testing would be beneficial in diseases such as these.
A client who tests positive for a mutation in the BRCA1 gene allele asks a nurse to be present when she discloses this information to her adult daughter. How would the nurse respond? a. "I will request a genetic counselor who is more qualified to be present for this conversation." b. "The test results can be confusing; I will help you interpret them for your daughter." c. "Are you sure you want to share this information with your daughter, who may not test positive for this gene mutation?" d. "This conversation may be difficult for both of you; I will be there to provide support."
ANS: D A nurse would provide emotional support while the client tells her daughter the information she has learned about the test results. The nurse would not interpret the results or counsel the client or her daughter. The nurse would refer the client for counseling or support, if necessary.
A nurse cares for an adult client who has received genetic testing. The patient's mother asks to receive the results of the genetic tests. Which action would the nurse take? a. Obtain a signed consent from the client allowing test results to be released to the mother. b. Invite the mother and other family members to participate in genetic counseling with the client. c. Encourage the mother to undergo genetic testing to determine if she has the same risks as her child. d. Direct the mother to speak with the client and support the client's decision to share or not share the results.
ANS: D All conversations and test results must be kept confidential. The client has the right to determine who may be involved in discussions related to diagnosis and genetic testing, who may participate in genetic counseling with the patient, and what information may be disclosed to family members. It is the nurse's responsibility to provide a private environment for discussions and protect the patient's information from improper disclosure. The nurse would support the patient's right to disclose or not disclose information.
