ch11.doc

[Osborn] chapter 11

Learning Objectives [Number and Title] Learning Objective 1 Describe the role of genetics in health care and nursing.Learning Objective 2 Discuss events of cell division that result in chromosomal

abnormalities.Learning Objective 3 Describe the organization of the human genome and the DNA

sequence.Learning Objective 4 Describe the influence of the genome on differences among

patients.Learning Objective 5 Identify patterns of inheritance and variables influencing

interpretation of inheritance patterns.Learning Objective 6 Discuss the role of nurses in detection, management, and care

of patients with genetic disorders.Learning Objective 7 Describe emerging genetic technologies and therapies.

Osborn, et al., Test Item File for Medical-Surgical Nursing: Preparation for PracticeCopyright 2010 by Pearson Education, Inc.

1. The nurse recognizes that a chromosomal analysis of a newborn baby is most likely to include which of the following laboratory tests?

1. Karyotype2. Newborn screen3. Carrier testing4. Preimplantation genetic diagnosis

Correct Answer: Karyotype

Rationale: The karyotype provides an analysis of the number and structure of the chromosomes. Newborn screening seeks to identify inborn errors of metabolism. Carrier testing is completed on asymptomatic individuals who may be carriers of one copy of a gene alteration that can be transmitted to future children in an autosomal recessive or X-linked pattern of inheritance. Preimplantation genetic testing in human embryos just after in vitro fertilization and before implantation in the uterus involves the detection of disease-causing gene alterations.

Cognitive Level: ApplyingNursing Process: AssessmentClient Need: Health Promotion and MaintenanceLO: 1


2. A female patient tells the nurse that she is genetically predisposed to type 2 diabetes. Which of the following is the most important information for this patient?

1. The importance of maintaining a healthy weight and activity level2. The need to avoid carbohydrate intake3. The need to begin monitoring daily blood glucose levels4. The need to address active health problems and not those that have yet to manifest

Correct Answer: The importance of maintaining a healthy weight and activity level

Rationale: The best way for this patient to avoid illness is to maintain a healthy weight and activity level. While nutrition is a significant factor, it is not necessary to avoid carbohydrates. Daily monitoring of blood glucose levels is not indicated for this patient. It is important to take action to prevent disease and not wait for the disease to manifest.

Cognitive Level: ApplyingNursing Process: ImplementationClient Need: Health Promotion and Maintenance LO: 1


3. A patient tells the nurse that she does not want to pass on a disease that is genetic in origin to any future children. The nurse would most correctly respond to this patient with which of the following statements?

1. “A complete genetic study could help guide you in your decision making.”2. “I supposed, then, that you are not going to have any children.”3. “Adoption is always a possibility.”4. “Are you sure that the disease is genetic in origin?”

Correct Answer: “A complete genetic study could help guide you in your decision making.”

Rationale: Findings from genetic research can be used by patients and family members to improve their own health and prevent illness. It is premature to suggest adoption or refraining from having children until the genetic study is completed. Questioning whether a specific disease is genetic in origin may be helpful, but may not allay the patient’s concerns about other diseases.



4. The nurse is educating a parent about the cause of a child’s Down syndrome. Which of the following is the best description of the cause? Down syndrome is caused when:

1. Aneuploidy occurs. 2. Mendelian inheritance occurs.3. Autosomal dominant inheritance occurs.4. Genome imprinting occurs.

Correct Answer: Aneuploidy occurs.

Rationale: Down syndrome is caused when aneuploidy, an abnormality in the number of chromosomes, occurs. Mendelian inheritance and autosomal dominant inheritance are examples of single-gene disorders. Genome imprinting is caused by an alteration in chromatin.

Cognitive Level: ApplyingNursing Process: ImplementationClient Need: Psychosocial IntegrityLO: 2


5. While assessing a patient, the nurse notes an irregularity that has been observed in other patients, but on an inconsistent basis. This nurse has most likely discovered a(n):

1. Polymorphism.2. Mutation.3. Single-gene inheritance pattern.4. X-linked inheritance pattern.

Correct Answer: Polymorphism. Rationale: Polymorphisms differ from mutations in that they are observed more frequently in the general population than mutations. Polymorphisms and mutations are key determinants of an individual’s observable traits, or phenotype, and clinical status. Whether the gene variation is identified as a mutation or polymorphism has more to do with how often the allele is observed instead of whether the allele is harmful or beneficial. A mutationis a change in DNA sequence that has been identified in less than 1% of the population. A polymorphism is a change in DNA sequence that has been identified in more than 1% of the population and is thus more commonly observed than a mutation. A single-gene inheritance pattern will follow a pattern of being present in every member of a generation or will skip a generation, depending on whether the alteration is dominant or recessive. In the X-linked inheritance pattern, the mutant gene is located on the X chromosome. Males have only one X chromosome with no counterpart for the genes; therefore the alteration will appear in all males. Because the female has two X chromosomes, the alteration may or may not occur.



6. A patient has been told that her unborn child will most likely have Down syndrome. The nurse realizes this diagnosis is consistent with:

1. Trisomy.2. Monosomy.3. Translocation.4. Deletions.

Correct Answer: Trisomy.

Rationale: Trisomy refers to the presence of a third or extra chromosome instead of the normal pair of a particular chromosome. The most common type of trisomy in infants is trisomy 21 or Down syndrome. The chromosome number and structure seen in 95% of individuals with Down syndrome is 47, XX or 47, XY. Monosomy refers to the presence of only one chromosome instead of the normal pair of chromosomes. Monosomy for an entire chromosome usually results in death, except for Turner syndrome or the monosomy for the X chromosome (45, X). Translocations occur when there are breaks in two or more chromosomes with reattachments in new combinations. They are generally harmless, though these translocations are more common among individuals with intellectual disabilities. Structural rearrangements of chromosomes may result from deletions or loss of a chromosome segment or piece; individuals may have moderate to severe mental retardation, Williams syndrome, or Prader-Willi syndrome.

Cognitive Level: ApplyingNursing Process: ImplementationClient Need: Health Promotion and MaintenanceLO: 2


7. A nurse reviewing the binding sequence of the human gene realizes that guanine will always bind with:

1. Cytosine.2. Adenine.3. Phosphate.4. Thymine.

Correct Answer: Cytosine.

Rationale: DNA is composed of four nucleotide bases, adenine (A), cytosine (C), guanine (G), and thymine (T), with the addition of sugar (deoxyribose) and phosphate. The purine bases are A and G, and the pyrimidine bases are C and T. In DNA, purines and pyrimidines always pair in a complementary nature so that A always binds to T and C always binds to G.

Cognitive Level: ApplyingNursing Process: AssessmentClient Need: Health Promotion and Maintenance LO: 3


8. The building blocks of DNA include: 1. Sugar, phosphate, and four nucleotide bases.2. Adenosine, cytosine, glucosamine, and thymine. 3. Purine sugars and pyrimidine phosphate.4. Chromosomes with mRNA proteins.

Correct Answer: Sugar, phosphate, and four nucleotide bases.

Rationale: The building blocks of DNA include four nucleotide bases plus sugar and phosphate. The four nucleotide bases are adenine, cytosine, guanine, and thymine. The four bases are of two types: purines and pyrimidines. Genes are made of DNA.

Cognitive Level: ApplyingNursing Process: AssessmentClient Need: Physiological IntegrityLO: 3


9. The nurse is explaining to a client how genes express certain genetic traits. Which of the following explanations is correct?

1. Every cell contains the individual’s entire genome, but each gene is not expressed by each cell.

2. Every cell contains 46 chromosomes, and when sugar and phosphates attach to the cell, each chromosome is expressed.

3. Every cell contains active and inactive DNA, and active DNA in each gene controls the cell’s activity.

4. Every cell contains 23 pairs of chromosomes, and each gene is expressed by interaction with the cell’s building blocks A, C, G, and T.

Correct Answer: Every cell contains the individual’s entire genome, but each gene is not expressed by each cell.

Rationale: Every cell contains the individual’s entire genome, but each cell does not express each gene. As cells specify, they develop different coding and act differently to make up all the different organs and cells in the body. Sugar and phosphates do not cause expression of the cell. A, C, G, and T make up the chromosomes within the nucleus. Expression of the cell occurs with mRNA (not DNA), which is decoded to produce a protein designated by a gene.

Cognitive Level: AnalyzingNursing Process: EvaluationClient Need: Physiological IntegrityLO: 3


10. A nurse is planning to teach the parents of a child with cystic fibrosis how the disease is manifested. Which of the following statements is the best explanation?

1. “While all people carry the gene for cystic fibrosis, those who develop the disease have a mutation in that gene.”

2. “A small percentage of the general population carries the gene for cystic fibrosis. If two carriers have children, then 25% of those children will develop the disease.”

3. “One in four people carry the gene for cystic fibrosis. If two carriers have children, then 25% of those children will develop the disease.”

4. “Some people carry the gene for cystic fibrosis. Of those carriers, one in four will develop the disease.”

Correct Answer: “While all people carry the gene for cystic fibrosis, those who develop the disease have a mutation in that gene.”

Rationale: Every individual carries the cystic fibrosis transference regulator gene. Those who develop the disease have a mutation in that gene. The other answer choices are all incorrect, as they indicate that only a few carry the gene for cystic fibrosis.

Cognitive Level: ApplyingNursing Process: PlanningClient Need: Psychosocial IntegrityLO: 4


11. A patient tells the nurse that many of her family members have a type of anemia that is genetic. The nurse realizes that this patient will:

1. Develop the disease only if there is a mutation in the gene.2. Develop the same type of anemia.3. Die from the anemia.4. Develop the disease only if the gene translocates.

Correct Answer: Develop the disease only if there is a mutation in the gene.

Rationale: All humans have essentially the same 20,000 to 25,000 genes; it is the mutation or polymorphism in the gene, not translocation nor the gene itself, that predisposes some individuals for disease. The patient may or may not develop or die from anemia.

Cognitive Level: AnalyzingNursing Process: AssessmentClient Need: Health Promotion and Maintenance LO: 4


12. A baby is born with a genetic disorder. Neither parent has a history of this disorder. The nurse realizes that the cause of this disorder can be explained as being:

1. De novo.2. Penetrance.3. An X-linked dominant condition.4. Evidence to justify the need for a paternity test.

Correct Answer: De novo.

Rationale: When there is no previous history of a condition in any other immediate or distant family member, including even subtle signs and symptoms of the disease, the disease may be caused by a spontaneous new mutation. This is called "de novo." Penetrance is the probability that a gene will be expressed phenotypically. X-linked conditions are recessive in nature. The need for a paternity test is not influenced by genetic conditions.

Cognitive Level: ApplyingNursing Process: ImplementationClient Need: Health Promotion and MaintenanceLO: 4


13. Which of the following disorders is caused by a single-gene disorder?1. Huntington disease2. Alzheimer disease3. Prader-Willi syndrome4. Obesity

Correct Answer: Huntington disease

Rationale: Huntington disease is caused by a single-gene disorder. Prader-Willi syndrome is a chromosomal genetic disorder. Alzheimer disease and obesity are complex multifactorial disorders, resulting from a combination of small variations in genes.

Cognitive Level: ApplyingNursing Process: DiagnosisClient Need: Physiological IntegrityLO: 5


14. A patient is diagnosed with color blindness. The nurse realizes this genetic disorder is considered:

1. An X-linked recessive disorder.2. An X-linked dominant disorder.3. A chromosomal nondisjunction.4. A chromosomal deletion.

Correct Answer: An X-linked recessive disorder.

Rationale: Color blindness is considered an X-linked recessive disorder. Color blindness is not an X-linked dominant disorder; an example of an X-linked dominant disorder is vitamin D resistance rickets. Chromosomal nondisjunction is the failure of a pair of chromosomes to separate properly during meiosis. Chromosomal deletion is a loss of a chromosome segment or piece. Cognitive Level: ApplyingNursing Process: AssessmentClient Need: Health Promotion and Maintenance LO: 5


15. A client tells the nurse that her mother has type 2 diabetes and heart problems. The nurse realizes that this information:

1. Can help in suggesting lifestyle changes that will positively impact the client’s future health.

2. Has little effect on the client’s health, since neither are related to family genetics.3. Helps predict the future health of the client’s children.4. Means that the client will experience major health issues in the future.

Correct Answer: Can help in suggesting lifestyle changes that will positively impact the client’s future health.

Rationale: Both type 2 diabetes and cardiac problems can be seen to “run in families.” Being aware of such disease processes allows for the introduction of diet, exercise, and stress reduction strategies that will have a positive affect on minimizing or even preventing these conditions. It is therefore not easy to predict the future health of the client or the client’s children.

Cognitive Level: ApplyingNursing Process: AssessmentClient Need: Health Promotion and MaintenanceLO: 5


16. The nurse assesses a patient’s family health history for three generations. This nurse is determining the patient’s:

1. Pedigree.2. Expressivity.3. Inheritance.4. Penetrance.

Correct Answer: Pedigree.

Rationale: Recognizing patterns of inheritance and clustering of diseases within families can be determined based on a thorough family history that is organized into a family tree, called a pedigree. Pedigrees enable the health care provider to visualize how diseases and characteristics are clustered within a family and through generations. Expressivity is the degree to which a person with a specific genotype is affected. Penetrance is the proportion of individuals who have the genotype and actually manifest the disease or trait. Inheritance refers to the clustering of diseases through the recognition of genetic patterns.

Cognitive Level: AnalyzingNursing Process: AssessmentClient Need: Health Promotion and MaintenanceLO: 6


17. The mother who has just given birth to an infant displaying the physical signs of Down syndrome refuses to allow any family members to visit her or the newborn. The nurse realizes that this client is demonstrating:

1. Shame.2. Postpartum depression.3. Denial.4. Poor bonding.

Correct Answer: Shame.

Rationale: Guilt and shame are very common as a client deals with the loss of the expectation and dream of a healthy child. There is no evidence that the mother is in denial or has poor bonding with the infant. Postpartum depression is not an immediate response.

Cognitive Level: Applying Nursing Process: AssessmentClient Need: Psychosocial IntegrityLO: 6


18. A client has a strong family history of nonpolyposis colorectal cancer. What is the best advice the nurse can give to the client?

1. Have a genetic test to detect the presence of the genetic disorder, even though the client may never develop cancer.

2. Teach the client the symptoms indicating colon cancer and suggest a high-fiber diet to prevent cancer.

3. Have regular colonoscopies. If the colonoscopy is abnormal, then genetic testing is indicated.

4. Have a genetic test to detect the presence of colorectal cancer so that treatment can be initiated as early as possible.

Correct Answer: Have a genetic test to detect the presence of the genetic disorder, even though the client may never develop cancer.

Rationale: The client should be advised to have a test to detect the presence of the genetic mutation that causes nonpolyposis colorectal cancer. If the test is positive, the client has an 80% chance of developing the cancer. Some (20%) do not develop the cancer, though frequent medical monitoring would be important. Teaching the client the symptoms indicating colon cancer and suggesting a high-fiber diet to prevent cancer is important but not enough with the technology available today. Therapy would only be started if the cancer is present.

Cognitive Level: EvaluationNursing Process: PlanningClient Need: Health Promotion and MaintenanceLO: 6


19. A young mother about to give birth wants to harvest and save her stem cells. Which of the following statements made by this patient indicates the need for further teaching?

1. “I know my baby can be cured with these stem cells if he develops leukemia.”2. “I heard that these stem cells can become any type of cell in the body.”3. “These stem cells come from the baby’s blood in the placenta.”4. “I heard that if my baby has a spinal cord injury, these stem cells might be able to

help repair the spinal cord.”

Correct Answer: “I know my baby can be cured with these stem cells if he develops leukemia.”

Rationale: Stem cells offer help and transplant is sometimes successful to cause cancer remission. However, stem cell transplant is not always successful. The other responses are true and indicate that the young mother understands the potential uses of stem cells.

Cognitive Level: AnalyzingNursing Process: EvaluationClient Need: Health Promotion and MaintenanceLO: 7


20. A patient is diagnosed with hepatitis C. The nurse realizes the genetic test that might prove beneficial to this patient is:

1. Real-time PCR.2. Microarray analysis.3. Gene therapy.4. Stem cell therapy.

Correct Answer: Real-time PCR.

Rationale: Real-time PCR is an emerging technology that allows for the detection and quantification of a small fragment of replicating DNA during the amplification process and offers rapid and sensitive quantification of the gene of interest. Clinically, real-time PCR is used to obtain viral load levels of many different viruses, including cytomegalovirus and hepatitis C. Microarray analysis, primarily used in the research setting, is transitioning into clinical practice, specifically in the area of cancer prognosis and treatment stratification. Gene therapy and stem cell therapy are not genetic tests.



21. A patient has been diagnosed with type 1 diabetes. The nurse realizes that this patient might benefit from which of the following genetic technologies?

1. Stem cell therapy2. Microarray analysis3. Real-time PCR4. Gene therapy

Correct Answer: Stem cell therapy

Rationale: Stem cells are unspecialized cells that have the potential to divide without limit and to develop into specialized cells such as insulin-producing cells of the pancreas. Microarray analysis is primarily used in the research setting, specifically in the area of cancer prognosis and treatment stratification. Real-time PCR is an emerging technology that allows for the detection and quantification of a small fragment of replicating DNA during the amplification process and offers rapid and sensitive quantification of the gene of interest. Gene therapy is the correction of a genetic mutation by the introduction of DNA into a cell as a treatment modality to improve the patient’s health.



ch11.doc

Documents

title learning objective

genetic research

genetic disorders

complete genetic study

learning objectives

emerging genetic technologies

female patient

activity level rationale