Chapter 4: Genetic and Genomic Concepts for Medical-Surgical Nursing

Chapter 4: Genetic and Genomic Concepts for Medical-Surgical Nursing

Complete Chapter Questions With Answers

Sample Questions Are Posted Below

MULTIPLE CHOICE

1. 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 of her family members, is expressed more frequently in males than females. How should the nurse respond?
   1. “Females have a decreased penetrance rate for this gene mutation and are therefore less likely to express the trait.”
   2. “Females have two X chromosomes and one is always inactive. This inactivity decreases the effect of the gene.”
   3. “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.”
   4. “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.

DIF:     Understanding/Comprehension         REF: 59                       KEY: Genetics| sex-linked recessive                                                         MSC: Integrated Process: Teaching/Learning NOT:             Client Needs Category: Health Promotion and Maintenance

2. A client is typed and crossmatched for a unit of blood. Which statement by the nurse indicates a need for further genetic education?
   1. “Blood type is formed from three gene alleles: A, B, and O.”
   2. “Each blood type allele is inherited from the mother or the father.”
   3. “If the client’s blood type is AB, then the client is homozygous for that trait.”
   4. “If the client has a dominant and a recessive blood type allele, only the dominant

will be expressed.”

ANS:   C

There are three possible gene alleles: A, B, and O. Blood type is determined by only two of the three specific gene alleles. The blood type OO is homozygous in contrast to the blood type AB, which is heterozygous. In the blood type AO, the gene allele A is dominant and will be expressed as blood type A. It is true that each blood type allele is inherited from the mother or the father.

DIF:            Understanding/Comprehension         REF:    58

KEY:          Genetics| gene| allele| blood type

MSC:          Integrated Process: Nursing Process: Intervention                 NOT: Client Needs Category: Physiological Integrity: Physiological Adaptation

3. A nurse cares for a client of Asian descent who is prescribed warfarin (Coumadin). What action should the nurse perform first?
   1. Schedule an international normalized ratio (INR) test to be completed each day.
   2. Initiate fall precautions and strict activity limitations.
   3. Teach the client about bleeding precautions, including frequent checks for any bruising.
   4. Confirm the prescription starts warfarin at a lower-than-normal dose.

ANS:           D

Most individuals of Asian heritage have a single nucleotide polymorphism in the CYP2C19 gene that results in low activity of the enzyme produced. This mutation greatly reduces the metabolism of warfarin, leading to increased bleeding risks and other serious side effects. Any person of Asian heritage who needs anticoagulation therapy should be started on very low dosages of warfarin and should have his or her INR monitored more frequently. The nurse can always teach about the risk of bleeding and can monitor for any bruising. The priority action is for the nurse to check the prescription and confirm the dose prior to administering the medication. It is not necessary to initiate fall precautions and to limit activity based on the administration of warfarin.

DIF:            Applying/Application                         REF:    56                     KEY: Genetics| genetic mutations| cultural awareness                                                  MSC: Integrated Process: Nursing Process: Implementation                                                      NOT: Client Needs Category: Physiological Integrity: Pharmacological and Parenteral Therapies

4. A nurse obtains health histories when admitting clients to a medical-surgical unit. With which client should the nurse discuss predisposition genetic testing?
   1. Middle-aged woman whose mother died at age 48 of breast cancer
   2. Young man who has all the symptoms of rheumatoid arthritis
   3. Pregnant woman whose father has sickle cell disease
   4. Middle-aged man of Eastern European Jewish ancestry

ANS:           A

A client with a family history of breast cancer should be provided information about predisposition testing. Predisposition testing should 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 should 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 should be given information about carrier genetic testing.

DIF:            Applying/Application                         REF:    58

KEY:          Genetics| genetic testing

MSC:          Integrated Process: Nursing Process: Assessment

NOT:          Client Needs Category: Physiological Integrity: Reduction of Risk Potential

5. 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 should the nurse respond?
   1. “I will request a genetic counselor who is more qualified to be present for this conversation.”
   2. “The test results can be confusing; I will help you interpret them for your daughter.”
   3. “Are you sure you want to share this information with your daughter, who may not test positive for this gene mutation?”
   4. “This conversation may be difficult for both of you; I will be there to provide

support.”

ANS:           D

A nurse should provide emotional support while the client tells her daughter the information she has learned about the test results. The nurse should not interpret the results or counsel the client or her daughter. The nurse should refer the client for counseling or support, if necessary.

DIF:            Applying/Application                         REF:    60

KEY:          Genetics| advocacy| support

MSC:          Integrated Process: Nursing Process: Implementation

NOT:          Client Needs Category: Psychosocial Integrity

A nurse consults a genetic counselor for a client whose mother