Chapter 3

Question 1

1. A father and mother are carriers of phenylketonuria (PKU). Their 2-year-old daughter has the condition. The couple tells the nurse that they are having a second baby. Because their daughter has PKU, they are certain that this baby will not be affected. Which response by the nurse is the most accurate?
   a. “Good planning. You need to take advantage of the odds that are in your favor.”
   b. “I think you’d better first check with your physician.”
   c. “You are both carriers; therefore, each baby has a 25% chance of being affected.”
   d. “The ultrasound indicates a boy, and boys are not affected by PKU.”

Answer 1

ANS: C
Each child conceived by this couple has a one-in-four chance of being affected with the PKU disorder. This couple still has an increased likelihood of having a child with PKU; having one child already with PKU does not guarantee that they will not have another. These parents need to discuss their options with their physician. However, an opportune time has presented itself for the couple to receive correct teaching about inherited genetic risks. No correlation exists between gender and inheritance of the disorder, because PKU is an autosomal recessive disorder.

Question 2

2. A client is 5 months pregnant. On a routine ultrasound scan, the physician discovers that the fetus has a diaphragmatic hernia. The woman becomes distraught and asks the nurse what she should do. Which response would be most suitable?
   a. Talk to the client, and refer her to a genetic counselor.
   b. Suggest that the client travel to a fetal treatment center for intrauterine surgery.
   c. Tell her that everything is going to be fine.
   d. Sit with the client, and calmly suggest that she consider terminating this pregnancy.

Answer 2

ANS: A
Before the client makes any decisions, she should discuss this newly discovered information with a genetic counselor. Genetic counselors can help with the diagnosis and management of families affected by genetic conditions. The discussion of potential surgery should be pursuant to genetic counseling. Telling the woman that everything is going to be fine may give her false hope and is not accurate. All options should be discussed with the genetic counselor. Furthermore, the guiding principle for genetic counseling is nondirection, which respects the right of the individual or family who are being counseled to make autonomous decisions.

Question 3

3. A client who is gravida 2 and 16 weeks of gestation comes in for her prenatal appointment. Her 2-year-old daughter is with her and is wearing a sleeveless top. While interacting with her daughter, you note axillary freckling and several café-au-lait spots (>2 cm). In reviewing her chart, the nurse should assess for documentation of which genetic disease?
   a. Tay-Sachs disease
   b. Galactosemia
   c. Neurofibromatosis (NF)
   d. PKU

Answer 3

ANS: C
Clinical manifestations of NF may include axillary freckling and café-au-lait spots. Tay-Sachs disease is an incurable lipid-storage disorder and is not associated with café-au-lait spots. Galactosemia is an inborn error of metabolism and is also not associated with café-au-lait spots. PKU is not associated with café-au-lait spots. A child with PKU would have difficulty manufacturing the liver enzyme phenylalanine.

Question 4

4. A new father has just been told that his infant has trisomy 18. Which identifying physical feature is unique to an infant with this genetic disorder?
   a. Microcephaly and capillary hemangiomas
   b. Epicanthal folds and a simian crease
   c. Oblique palpebral fissures and Cri du chat syndrome
   d. Rocker-bottom feet and clenched hands with overlapping fingers

Answer 4

ANS: D
Rocker-bottom feet and clenched hands with overlapping fingers are associated with trisomy 18. Microcephaly and capillary hemangiomas are associated with trisomy 13. Epicanthal folds and a simian crease are associated with trisomy 21 (Down syndrome). Deletion of the short arm of chromosome number 5 is manifested by Cri du chat syndrome.

Question 5

5. A nurse is assessing the knowledge of new parents of a child born with Klinefelter syndrome. Which statement accurately describes this genetic disorder?
   a. Klinefelter syndrome is a sex chromosome abnormality.
   b. It affects only female children.
   c. The disorder is expressed as trisomy XYY.
   d. The child with this disorder will grow to be infertile.

Answer 5

ANS: A
Klinefelter syndrome, also known as trisomy XXY, is a sex chromosomal deviation that is expressed in males. Turner syndrome (monosomy X) is displayed in females. Most males with Klinefelter syndrome are tall, may be infertile, and are slow to learn; however, those who have mosaic Klinefelter syndrome may be fertile as adults.

Question 6

6. Which factor is least likely to influence the decision to undergo genetic testing?
   a. Anxiety and altered family relationships
   b. Cost of testing or denial of insurance benefits
   c. Imperfection of test results
   d. Ethnic and socioeconomic disparity associated with genetic testing

Answer 6

ANS:	B
Testing is not 100% accurate and has a high percentage of false-negative results. An individual may not take these results seriously and subsequently fail to have testing completed or to seek necessary follow-up consultation. Anxiety and altered family relationships are often the result of genetic testing. The results of genetic testing may be difficult to keep confidential, and family members may feel pressured to have testing performed. Decisions about genetic testing are shaped by socioeconomic status and the ability to pay for the testing. Some types of genetic testing are expensive and are not covered by insurance benefits. Caucasian middle-class families have greater access to genetic screening; therefore, this population is less at likely to decide against genetic testing.

Question 7

7. A 32-year-old woman is pregnant for the third time. One child was born with cystic fibrosis, and the other child is healthy. The client and her husband wonder what chance this child has of having cystic fibrosis. This type of testing is most commonly known as what?
   a. Occurrence risk
   b. Recurrence risk
   c. Predictive testing
   d. Predisposition testing

Answer 7

ANS: B
The couple already has a child with a genetic disease; therefore, this couple will be given a recurrence risk test. If a couple has not yet had a child but is known to be at risk for having a child with a genetic disease, then an occurrence risk test is administered. Predictive testing clarifies the genetic status of an asymptomatic family member. Predisposition testing differs from presymptomatic testing in that a positive result does not indicate 100% risk of a condition developing.

Question 8

8. Cancer is now recognized as a genetic disorder that begins with one or more genetic mutations. Which type of cancer is specifically being investigated in this regard?
   a. Lung cancer
   b. Liver cancer
   c. Colorectal cancer
   d. Oral cancer

Answer 8

ANS: C
Colorectal cancer usually results from one or more predisposing genes and is the third leading cause of cancer deaths in women. Although tobacco smoke is a known causative factor for lung cancer, an acquired mutation of an oncogene may also be present. Liver cancer is not being investigated in this regard. Oral cancer may be caused by an inherited mutation of one or more oncogenes.

Question 9

9. Which statement describes a key finding of the Human Genome Project?
   a. Humans produce one protein per gene.
   b. All human beings are 99.9% identical at the deoxyribonucleic acid (DNA) level.
   c. The Human Genome Project has not yet been able to translate the accumulating raw research into anything medically practical.
   d. Humans have more genes than other species.

Answer 9

ANS: B
The majority of the 0.1% genetic variations are found within and not among populations. Most human genes produce at least three proteins. The project’s research has been very valuable in the identification of genes involved in disease and in the development of genetic testing. There are 20,500 genes in the human genome; scientists originally estimated more than 50,000 genes. Human genes are more efficient than the genes in other species, thereby increasing the human genetic complexity.

Question 10

10. Which condition or treatment reduces the risk of morbidity in women with the inherited factor V Leiden disorder?
    a. Anticoagulant therapy
    b. Pregnancy
    c. Oral contraceptives
    d. Hormone replacement therapy

Answer 10

ANS: A
Factor V Leiden is the most common inherited risk factor for primary or recurrent venous thromboembolism. It is an autosomal recessive disorder that increases an individual’s risk for blood clots in the legs and pulmonary emboli. This risk significantly increases if the woman is pregnant or is taking oral contraceptives or hormone replacement therapy. Prophylactic anticoagulation therapy decreases the risk of comorbidities.

Question 11

11. Nurses who elect to practice in the field of obstetrics must have a basic working knowledge of genetics. What is the correct term used to describe an individual’s genetic makeup?
    a. Genotype
    b. Phenotype
    c. Karyotype
    d. Chromotype

Answer 11

ANS: A
The genotype comprises all the genes the individual can pass on to a future generation. The phenotype is the observable expression of an individual’s genotype. The karyotype is a pictorial analysis of the number, form, and size of an individual’s chromosomes. Genotype refers to an individual’s genetic makeup.

Question 12

12. The U.S. Department of Health and Human Services has designated Thanksgiving Day as National Family History Day. The U.S. Surgeon General encourages family members to discuss important family health information while sharing in holiday gatherings. Why is this initiative significant to nurses?
    a. Few genetic tests are available that identify this information.
    b. Only physicians should obtain this detailed information.
    c. Clients cannot accurately complete these histories on their own.
    d. Family history is the single most cost-effective source for genetic information.

Answer 12

ANS: D
Although more than 1000 genetic tests are available, the single most cost-effective piece of genetic information is the family history. Nurses are ideally suited to take the lead in ongoing efforts to recognize the significance of the family history as an important source of genetic information. A computerized tool called My Family Health Portrait is available free of charge (https://familyhistory.hhs.gov/fhh-web/home.action). Other tools designed to help the lay community in completing their family histories are available to the public.

Question 13

13. A maternal-newborn nurse is caring for a mother who just delivered a baby born with Down syndrome. Which nursing diagnosis would be the most essential in caring for the mother of this infant?
    a. Disturbed body image
    b. Interrupted family processes
    c. Anxiety
    d. Risk for injury

Answer 13

ANS: B
This mother will likely experience a disruption in the family process related to the birth of a baby with an inherited disorder. Therefore, the probable nursing diagnosis for this family is “Interrupted family processes.” Women commonly experience “body image disturbances in the postpartum period”; however, this nursing diagnosis is unrelated to giving birth to a child with Down syndrome. The mother will likely have a mix of emotions that may include anxiety, guilt, and denial, but this nursing diagnosis is not the most essential for this family. “Risk for injury” is not an applicable nursing diagnosis.

Question 14

14. A couple has been counseled for genetic anomalies. They ask you, “What is karyotyping?” Which description is most accurate?
    a. “Karyotyping will reveal if the baby’s lungs are mature.”
    b. “Karyotyping will reveal if the baby will develop normally.”
    c. “Karyotyping will provide information about the gender of the baby and the number and structure of the chromosomes.”
    d. “Karyotyping will detect any physical deformities the baby has.”

Answer 14

ANS: C
Karyotyping provides genetic information such as gender and chromosomal structure. The lecithin/sphingomyelin (L/S) ratio, not karyotyping, reveals lung maturity. Although karyotyping can detect genetic anomalies, the range of normal is nondescriptive, and not all such anomalies display obvious physical deformities. The term deformities is a nondescriptive word, and physical anomalies may be present that are not detected by genetic studies (e.g., cardiac malformations).

Question 15

15. Which statement regarding genetic health care is most important to the nurse practicing in this specialty?
    a. Genetic disorders equally affect people of all socioeconomic backgrounds, races, and ethnic groups.
    b. Genetic health care is more concerned with populations than individuals.
    c. Providing emotional support to the family during counseling is the most important of all nursing functions.
    d. Taking genetic histories is the province of large universities and medical centers.

Answer 15

ANS: C
Perhaps the most important of all nursing functions is the ability to provide emotional support. Nurses should be prepared to help with various stress reactions from a couple facing the possibility of a genetic disorder. Although anyone may have a genetic disorder, certain disorders appear more often in certain ethnic and racial groups. Genetic health care is highly individualized because treatments are based on the phenotypic responses of the individual. Individual nurses at any facility can take a genetic history, although larger facilities may have better support services.

Question 16

16. Which statement most accurately describes dominant genetic disorders?
    a. With a dominant disorder, the likelihood of the second child also having the condition is 100%.
    b. An autosomal recessive disease carries a one-in-eight risk of the second child also having the disorder.
    c. Disorders involving maternal ingestion of drugs carry a one-in-four chance of being repeated in the second child.
    d. The risk factor remains the same no matter how many affected children are already in the family.

Answer 16

ANS: D
Each pregnancy is an independent event. The risk factor (e.g., one-in-two, one-in-four) remains the same for each child, no matter how many children are born to the family. In a dominant disorder, the likelihood of recurrence in subsequent children is 50% (i.e., one-in-two). An autosomal recessive disease carries a one-in-four chance of recurrence. In disorders involving maternal ingestion of drugs, subsequent children would be at risk only if the mother continued to take the drugs; the rate of risk would be difficult to calculate.

Question 17

17. Which statement regarding chromosomal abnormalities is most accurate?
    a. Chromosomal abnormalities occur in approximately 10% of newborns.
    b. Abnormalities of number are the leading cause of pregnancy loss.
    c. Down syndrome is a result of an abnormal chromosomal structure.
    d. Unbalanced translocation results in a mild abnormality that the child will outgrow.

Answer 17

ANS: B
Aneuploidy is an abnormality of number that is also the leading genetic cause of mental retardation. Chromosomal abnormalities occur in fewer than 1% of newborns. Down syndrome is the most common form of a trisomal abnormality, an abnormality of chromosome number (47 chromosomes). Unbalanced translocation is an abnormality of chromosomal structure that often has serious clinical effects.

Question 18

18. Which type of genetic tests in clinical practice are most often offered to clients with a family history of disease?
    a. Single-gene disorders
    b. Carrier screening
    c. Predictive value testing
    d. Predispositional testing

Answer 18

ANS: A
Most tests now offered are tests for single-gene disorders in clients with clinical symptoms or clients who have a family history of a genetic disease. Carrier screening is used to identify individuals who have a gene mutation for a genetic condition but do not display symptoms. Predictive value testing is used only to clarify the genetic status of asymptomatic family members. Predispositional testing differs from the other types of genetic screening in that a positive result does not indicate a 100% chance of developing the condition.

Question 19

1. Which congenital malformations result from multifactorial inheritance? (Select all that apply.)
   a. Cleft lip
   b. Congenital heart disease
   c. Cri du chat syndrome
   d. Anencephaly
   e. Pyloric stenosis

Answer 19

ANS: A, B, D, E
Cleft lip, congenital heart disease, anencephaly, and pyloric stenosis are associated with multifactorial inheritance. Cri du chat syndrome is related to a chromosomal deletion.

Question 20

2. Which activities are included in the role of a nurse practicing in the field of genetics? (Select all that apply.)
   a. Assessing the responses of family members to a genetic disorder
   b. Performing genetic testing, such as amniocentesis
   c. Constructing a family pedigree of three or more generations
   d. Advising a pregnant mother whose fetus has a genetic disorder to have an abortion
   e. Offering parents information about genetics

Answer 20

ANS: A, C, E
Assessing the responses of family members, constructing a family pedigree, and offering parents information about genetics are activities that a genetics nurse would carry out in caring for a family undergoing genetic counseling. Physicians perform amniocentesis, but the nurse may assist in this procedure. Being aware of their own values and beliefs and refraining from attempting to influence the family are important responsibilities for nurses. The nurse must respect the right of the individual or family to make autonomous decisions.

Question 21

3. One of the most promising clinical applications of the Human Genome Project has been pharmacogenomic testing (the use of genetic information to guide a client’s drug therapy). Which conditions are potential candidates for pharmacogenomic application? (Select all that apply.)
   a. Fragile X syndrome
   b. Deep vein thrombosis (DVT)
   c. Breast cancer
   d. Myocardial infarction
   e. Hemophilia

Answer 21

ANS: B, C, D
Associations between genetic variation and drug effect have been observed for a number of commonly used drugs. The conditions for which these are applicable include: DVT, breast cancer, and myocardial infarction. Gene therapy has been unsuccessfully used in hemophilia treatment. Fragile X syndrome is the leading cause of intellectual disability and lacks effective treatment of any kind.

Question 22

A nurse is providing genetic counseling for an expectant couple who already have a child with trisomy 18. The nurse should:
A.Tell the couple they need to have an abortion within 2 to 3 weeks.
B. Explain that the fetus has a 50% chance of having the disorder.
C. Discuss options with the couple, including amniocentesis to determine whether the fetus is affected.
D. Refer the couple to a psychologist for emotional support.

Answer 22

Ans: C
The couple should be given information about the likelihood of having another baby with this disorder so that they can make an informed decision. A genetic counselor is the best source for determining genetic probability ratios. Genetic testing, including amniocentesis, would need to be performed to determine whether the fetus is affected. The couple eventually may need emotional support, but the status of the pregnancy must be determined first.

Question 23

You are a maternal-newborn nurse caring for a mother who just delivered a baby born with Down syndrome. What nursing diagnosis would be the most essential in caring for the mother of this infant?
  A. Disturbed body image
 B.  Interrupted family processes 
 C.  Anxiety
 D.  Risk for injury

Answer 23

Ans: B
Women commonly experience body image disturbances in the postpartum period, but this development is unrelated to giving birth to a child with Down syndrome. This mother likely will experience a disruption in the family process related to the birth of a baby with an inherited disorder. She likely will also have a mix of emotions that may include anxiety, guilt, and denial, but anxiety is not the most essential nursing diagnosis for this family. Risk for injury is not an applicable nursing diagnosis.

Question 24

A couple has been counseled for genetic anomalies. They ask you, “What is karyotyping?” Your best response is:
A. “Karyotyping will reveal whether the baby’s lungs are mature.”
B. “Karyotyping will reveal whether your baby will develop normally.”
C. “Karyotyping will provide information about the gender of the baby and the number and structure of the baby’s chromosomes.”
D. “Karyotyping will detect any physical deformities the baby has.”

Answer 24

Ans: C
The lecithin/sphingomyelin ratio, not karyotyping, reveals lung maturity. Although karyotyping can detect genetic anomalies, the range of normal is nondescriptive. Karyotyping provides genetic information, such as gender and chromosomal structure. Although karyotyping can detect genetic anomalies, not all such anomalies display obvious physical deformities. Deformities is a nondescriptive word. Furthermore, physical anomalies may be present that are not detected by genetic studies (e.g., cardiac malformations).

Question 25

With regard to the estimation and interpretation of the recurrence of risks for genetic disorders, nurses should be aware that:
A. With a dominant disorder, the likelihood of the second child also having the condition is 100%.
B. An autosomal recessive disease carries a one in eight risk that the second child will also have the disorder.
C. Disorders involving maternal ingestion of drugs carry a one in four chance of being repeated in the second child.
D. The risk factor remains the same no matter how many affected children are already in the family.

Answer 25

Ans: D
In a dominant disorder, the likelihood of recurrence in subsequent children is 50% (one in two). An autosomal recessive disease carries a one in four chance of recurrence. Subsequent children of a mother who used drugs would be at risk only if she continued to do so; the rate of risk would be difficult to calculate. Each pregnancy is an independent event. The risk factor (e.g., one in two, one in four) remains the same for each child, no matter how many children are born to the family.

Question 26

With regard to abnormalities of chromosomes, nurses should be aware that:
A. They occur in approximately 10% of newborns.
B. Abnormalities of number are the leading cause of pregnancy loss.
C. Down syndrome is a result of an abnormal chromosomal structure.
D. Unbalanced translocation results in a mild abnormality that the child will outgrow.

Answer 26

Ans: B
Chromosomal abnormalities occur in less than 1% of newborns. Aneuploidy is an abnormality of number that also is the leading genetic cause of mental retardation. Down syndrome is the most common form of trisomal abnormality, an abnormality of chromosome number (47 chromosomes). Unbalanced translocation is an abnormality of chromosome structure that often has serious clinical effects.

Question 27

A key finding from the Human Genome Project is:
A. Approximately 20,000 to 25,000 genes make up the genome.
B. All human beings are 80.99% identical at the DNA level.
C. Human genes produce only one protein per gene; other mammals produce three proteins per gene.
D. Single-gene testing will become a standardized test for all pregnant women in the future.

Answer 27

Ans: A
Approximately 20,500 genes make up the human genome, only twice as many as make up the genomes of roundworms and flies. Human beings are 99.9% identical at the DNA level. Most human genes produce at least three proteins. Single-gene testing (e.g., alpha-fetoprotein test) is already standardized for prenatal care.

Question 28

Most of the genetic tests now offered in clinical practice are tests for:
  A. Single-gene disorders. 
  B. Carrier screening.
  C.Predictive values.
  D. Predispositional testing.

Answer 28

Ans: A
Most tests now offered are tests for single-gene disorders in clients who have clinical symptoms or a family history of a genetic disease. Carrier screening is used to identify individuals who have a gene mutation for a genetic condition but do not display symptoms. Predictive testing is used only to clarify the genetic status of asymptomatic family members. Predispositional testing differs from the other types of genetic screening in that a positive result does not indicate a 100% chance that the condition will develop.

Question 29

The provider has ordered a genetic testing to assess whether the patient’s fetus is at risk for sickle cell disease. The patient is asymptomatic but relates a positive family history. On the basis of this information, the nurse realizes that the provider has ordered:
 A. Predictive testing.
 B. A carrier screening test. 
 C. Presymptomatic testing.
 D. Predispositional testing.

Answer 29

Ans: B

Carrier screening test would help identify whether the mother had the genetic mutation, thereby increasing the risk for transmission to the fetus. Predictive testing is used to determine genetic status of an asymptomatic family member. Presymptomatic testing would indicate the presence of a specific genetic mutation that is associated with a clinical presentation that would occur over the course of time. Because sickle cell disease is an autosomal recessive transmission and the patient is asymptomatic, such testing would not be indicated. Predispositional testing would also not be indicated because sickle cell disease is an autosomal recessive disease; if the patient is asymptomatic and a genetic mutation is found, it would exist only in a carrier state.

Question 30

A 38-year-old maternity patient receives information based on genetic testing that her fetus has a deformity and decides to terminate the pregnancy. There is a family history of genetic abnormalities. Following the termination of pregnancy, the pathology report indicates that the fetus had no structural abnormalities. This finding suggests that:
A. The patient should have asked for a second opinion from a perinatal specialist.
B. The genetic test results provided indicated a false-negative finding.
C. Genetic testing results vary with patient demographics and information provided.
D. Results indicated a false-positive finding leading to an adverse outcome.

Answer 30

Ans: D
Because the pathology report identified no abnormalities, the results of genetic testing in this case were false-positive, in that they indicated that there was an abnormality when there was not. This information unfortunately led to a poor health outcome. Although no genetic test provides 100% reassurance, most patients do not automatically seek a second opinion unless there are additional variables that may influence the reliability of the result. Because the patient had a family history of genetic abnormalities, it is unlikely that the patient and/or provider would necessarily have opted for a second opinion. A false-negative result would indicate that a condition was not present even though it was; the patient was provided with a negative result. Genetic test results do not vary with patient demographics or information provided.

Question 31

Which of the following statements are true with regard to Factor V Leiden? (Select all that apply.)
A. Factor V Leiden is an autosomal dominant disorder.
B. It increases the likelihood of DVT in an affected patient.
C. It is due to a mutation in factor IV and V genes.
D. A woman who has one copy of the gene should not use oral contraceptives as a birth control method.
E. Factor V Leiden leads to increased susceptibility of activated protein C.

Answer 31

Ans: A, B, D
Factor V Leiden is an inherited disorder via autosomal dominant transmission. Presence of this genetic mutation increases the likelihood for blood clots to develop. This genetic mutation is found in Factor V gene only.
A patient who tests positive for Factor V Leiden, regardless of whether she is homozygous or heterozygous for the trait, should not use oral contraceptives as a birth control method. The Factor V Leiden mutation leads to activated protein C resistance.