Ch. 13 Genetics and Genomics

A nurse is discussing basic genetics with a patient. The nurse knows that the basic unit of heredity information is located on what specific part of a chromosome? 1 Gene 2 Trait 3 Locus 4 Allele

1 The basic unit of heredity information located on a specific part of a chromosome is called a gene. Traits refer to physical characteristics that one inherits from parents. The locus is a position of a gene on a chromosome. An allele is an alternative form of a gene. Text Reference - p. 191

The genotypes of a mother and father are XX and XY respectively. The mother is a carrier for hemophilia, an X-linked recessive disorder. The nurse understands that what is the probability that a male child will be unaffected? 1 25% 2 50% 3 100% 4 75%

2 If the mother is a carrier for an X-linked recessive genetic disorder such as hemophilia, 50% of the male children will be affected and 50% of the male children will be normal. Text Reference - p. 201

A patient with breast cancer has undergone pharmacogenetic testing. The patient is prescribed Trastuzumab (Herceptin) after the test results are studied. What can the nurse interpret from this prescription? 1 The patient has a mutated BRCA1 gene. 2 The patient has a mutated BRCA2 gene. 3 There is excessive production of HER2 protein in the tumor genes. 4 There is deficient production of HER2 protein in the tumor genes.

3 Trastuzumab (Herceptin) is the ideal drug for breast cancer for those patients whose tumor has genes that lead to excessive production of HER2 protein. The nurse cannot interpret that the patient has a mutated BRCA1 or BRCA2 gene based on the prescription. Prescription of this drug does not indicate that the patient has deficient production of HER2 protein in the tumor genes. Text Reference - p. 199

A nurse is aware that the correct base pair found in DNA is what? 1 A G 2 A T 3 C T 4 C A

Adenine (A), guanine (G), cytosine (C), and thymine (T) in DNA are paired. These are called base pairs. In a strand of DNA, A pairs with T and C pairs with G to form units called base pairs. A does not pair with G, C does not pair with T, and C does not pair with A. Text Reference - p. 192

For which individual is genetic carrier screening indicated? 1 A patient with a history of type 1 diabetes 2 A patient with a family history of sickle cell disease 3 A patient whose mother and sister died of breast cancer 4 A patient who has a long-standing history of iron-deficiency anemia

Genetic carrier screening should be done in families with a history of sickle cell disease. Although there is a multifactorial genetic basis for diabetes (based on research), there are no genetic markers for testing for the presence of or risk of diabetes. A significant family history of breast cancer may suggest that presymptomatic testing for BRCA 1 and 2 may be indicated. Iron deficiency is not related to genetic status. Text Reference - p. 196

The nurse recalls that there are three copies of chromosomes, instead of two, in which genetic disorder? 1 Cystic fibrosis 2 Down syndrome 3 Sickle cell disease 4 Polycystic kidney disease

In Down syndrome, there are three copies of chromosomes instead of two. It is caused by an extra copy of chromosome 21. Cystic fibrosis, sickle cell disease, and polycystic kidney disease are caused by a single gene mutation. Text Reference - p. 194

A nurse is caring for a patient with thalassemia and explains the meaning of mutation. What would be appropriate for the nurse to include in the explanation? 1 It is a disease affecting only females. 2 It is a change in the normal sequence of DNA. 3 It is a disease that is caused by a sedentary lifestyle. 4 It is a disorder affecting the hearing and speech of an individual.

Mutation is a change that occurs in the normal sequence of DNA. It can be inherited or acquired. Genetic mutation can occur in both sexes. Mutation is not related to a sedentary lifestyle or lack of physical activity. Mutation is not a specific condition affecting hearing or speech. Genetic mutation can cause many health-related disorders, such as Down's syndrome, cystic fibrosis, and thalassemia. Text Reference - p. 193

The nurse is reviewing the role of pharmacogenetics in health care. Which of these reflects an understanding of pharmacogenetics? 1 The study of the effectiveness of a drug. 2 The study of an individual's response to drugs. 3 It provides important assessment data for gene therapy. 4 It can assess the variability of drug responses caused by single genes

Pharmacogenetics is the study of genetic variability of drug responses caused by a variation in single genes. At this time such tests are routine for only a few diseases/disorders. Pharmacogenetics is not the study of the effectiveness of the drug, the study of an individual's response to a drug, or important data for gene therapy. Text Reference - p. 198

A 35-year-old pregnant patient expresses concern to the nurse about the potential for cystic fibrosis in her children. What is the most appropriate nursing intervention? 1 Tell her that she needs to discuss the issue with a genetic counselor. 2 Inform her about the at-home genetic test kits available in the market. 3 Explain to her how to take the sample and mail it back to the laboratory. 4 Educate her on how to read and interpret the results of the genetic test.

The nurse should tell the patient to discuss the issue of genetic testing with her health care provider or a genetic counselor. Without appropriate counseling, there are chances that the patient could be misled or misinformed by the results of unproven or invalid tests, resulting in wrong decisions. The nurse should not encourage self-directed testing. The sample may not be properly collected when self-testing at home. A health care provider should be consulted so that important decisions can be made based on accurate information. Text Reference - p. 197

The nurse recalls that, if both parents are heterozygotes, what is the chance of transmitting an autosomal recessive disorder to any of their children? 1 25% of their children can be affected. 2 75% of their children can be affected. 3 50% of their children can be affected. 4 100% of their children can become carriers.

1

A newborn baby is diagnosed with Down syndrome. The health care provider tells the parents that it is a genetic disorder. While explaining the disorder to the parents, which is the most appropriate statement for the nurse to include? 1 "It occurs due to the presence of an extra copy of chromosome 21 in the cell." 2 "This condition occurs due to an excess of genes present in chromosome 21." 3 "This condition occurs due to an abnormality in the usual sequence of DNA in chromosome 21." 4 "It occurs due to the absence of a gene in chromosome 21."

1 Down syndrome is a chromosomal disorder that is caused by the presence of an extra copy of chromosome 21, also called trisomy 21. Therefore, there are three copies of this chromosome instead of two. The condition may cause mental and physical growth retardation. There is no abnormality (deficiency or excess) in the number of genes present in chromosome 21. There is no structural abnormality in the genes present in chromosome 21. No individual gene is absent in chromosome 21. Text Reference - p. 195

A patient has a father with polycystic kidney disease and does not want to have genetic testing done for the disease because of worries that the patient might lose health insurance if genetic abnormalities are found. Based on the nurse's knowledge of the Genetic Information Nondiscrimination Act (GINA), what should the nurse teach this patient? 1 GINA should protect the patient from this happening. 2 GINA does not extend to cover preexisting conditions. 3 GINA will only protect the patient after a diagnosis of polycystic kidney disease. 4 GINA health coverage nondiscrimination protection also extends to life insurance.

1 GINA prohibits discrimination in health care coverage and employment based on genetic information, but does not extend to life insurance, disability insurance, or long-term care insurance. Text Reference - p. 201

A nurse educator explains genetic mutations to a group of nursing students. While explaining germline mutation, which statement given by the nurse is most appropriate? 1 It is passed from parents to their children. 2 It is caused by exposure to toxins. 3 It results in the mutation of two gene pairs in a single chromosome. 4 It is not inherited but is developed by a person during his lifetime.

1 Germline mutations are passed from parents to children. Germline mutations are inherited and are not caused by exposure to toxins. Autosomal recessive disorders are caused by mutations occurring in two gene pairs on a chromosome. Acquired mutation can develop in a person and can occur anytime during his lifetime; it cannot be passed from one generation to the next. Text Reference - p. 193

A woman in the 8th month of her pregnancy asks a nurse about stem cell therapy. The nurse explains the various types of stem cells. What is the right time to collect stem cells from the embryo for stem cell culture preservation? 1 5th day of embryonic development 2 30th day of embryonic development 3 35thday of embryonic development 4 60th day of embryonic development

1 Stem cells are of two types - embryonic and adult. Embryonic stem cells are formed in the embryo at a very early stage of development, and they are usually obtained on 4th or 5th day after conception. Adult stem cells are obtained from adult organs. Embryonic stems cells are more potent and can differentiate into any type of cells. The stem cells remain undifferentiated for only 4 or 5 days. After 5 days the cells start differentiating to form various parts of the body. Text Reference - p. 200

A nurse is aware that what nitrogenous bases are found in deoxyribonucleic acid (DNA)? Select all that apply. 1 Adenine (A) 2 Guanine (G) 3 Cytosine (C) 4 Uracil (U) 5 Thymine (T)

1, 2, 3, 5 DNA contains four nitrogenous bases: adenine (A), guanine (G), cytosine (C), and thymine (T). Uracil is present in RNA but not in DNA. RNA is made up of adenine (A), guanine (G), cytosine (C), and uracil (U). Text Reference - p. 191

A patient has a negative genetic test result. How should the nurse interpret this finding? Select all that apply. 1 The patient is not affected by a particular disorder. 2 The patient is not a carrier of a specific genetic mutation. 3 The patient does not have an increased risk of developing a certain disease. 4 The patient needs interventions to prevent inheritance of a disorder. 5 The patient needs further testing to confirm a negative result.

1, 2, 3, 5 Interpreting genetic test results can be a challenging task as there are chances for misdiagnosis. A negative test report indicates absence of the particular disorder, and implies that the person is not a carrier of a specific genetic mutation. It indicates that the person does not have an increased risk of developing a certain disease. Therefore, if the genetic test is negative, further testing is required. Measures to prevent inheritance of the genetic disorder are relevant in people who have a confirmed genetic disorder. Text Reference - p. 197

A nurse is making rounds with students in an HIV/AIDS special care unit. The nurse asks about conditions other than HIV that can be confirmed with the polymerase chain reaction test (PCR test). Which answers given by the students are correct? Select all that apply. 1 "It can be used for identifying the DNA of criminal suspects." 2 "It can be used to determine the presence of biological relationships between people." 3 "It can be used to find the presence of any genetic abnormality in the fertilized embryo." 4 "It can be used to find out if an individual is a carrier of a mutated gene." 5 "It can be used to detect changes in the genes or chromosomes of the fetus before birth."

1, 2, 4 Polymerase chain reaction (PCR) is a quick and easy technique to create multiple copies of RNA or DNA from a small sample. This technique can be used to determine whether an individual is HIV positive or not. PCR testing also can be used in forensic testing to identify criminals. This test can also be used in paternity testing to establish biological relationships between people. PCR test is also helpful in finding mutations in genes, and to know if an individual is a carrier for a mutated gene. Preimplantation genetic testing is used to detect the presence of genetic abnormalities in the fertilized embryo. PCR test cannot be used to detect genetic abnormalities present in a fetus before birth. Prenatal genetic testing is used to detect changes in the genes or chromosomes of the fetus before birth. Text Reference - p. 197

A nurse is reviewing case records to identify potential candidates for stem cell therapy. The nurse identifies that stem cell therapy may be useful for patients with which conditions? Select all that apply. 1 Burns 2 Stroke 3 Vertigo 4 Renal calculi 5 Spinal cord injuries

1, 2, 5 Stem cells are unspecialized cells that can be used for regenerating any specialized tissue. Conditions such as burns, stroke, and spinal cord injury involve extensive damage to various tissues. Hence, stem cell therapy can be useful in these conditions. Vertigo and renal calculi do not involve damage or death of tissues; therefore stem cell therapy will not be useful for such conditions. Text Reference - p. 200

A patient has a family history of coronary artery disease and has been advised to see a genetic counselor. What information should the nurse include when teaching the patient about the purposes of genetic counseling and testing? Select all that apply. 1 Diagnosing an illness 2 Determining risk for a disorder 3 Assessing eligibility for employment 4 Verifying entitlement for medical insurance 5 Providing the basis for appropriate treatments

1, 2, 5 The nurse should inform the patient that genetic testing is done to diagnose an illness, determine the risk for a disorder, and provide the basis for appropriate treatment, as discussed with a genetic counselor. It can help to prevent or delay the development of disease conditions. With genetic testing, individuals can understand their risk of developing a disease and take preventive measures. Genetic testing is not used for determining employability or eligibility for medical insurance, as it is unethical. The Genetic Information Nondiscrimination Act (GINA) protects people from discrimination by employers and health insurance companies. Text Reference - p. 195

A patient asks the nurse, "What is DNA?" Which statements should the nurse include in the explanation to the patient? Select all that apply. 1 DNA is a nucleic acid that forms genes. 2 DNA is an enzyme that helps in digestion. 3 DNA stores the genetic information of the individual. 4 Every cell of the human body contains the same DNA. 5 DNA determines the rate of carbohydrate synthesis in the body.

1, 3, 4 Deoxyribonucleic acid (DNA) is a nucleic acid that forms genes. It stores the genetic information of individuals. Every somatic cell of human body contains the same DNA. It is not an enzyme that aids digestion. DNA dictates the rate of protein synthesis in the body. Text Reference - p. 191

A patient has undergone pharmacogenetic testing. The results reveal that the patient has a very active form of Cytochrome P450 enzyme. What could the nurse interpret from this result? 1 The patient has a slow rate of drug metabolism. 2 The patient has a rapid rate of drug metabolism. 3 The patient has a normal rate of drug metabolism. 4 The patient's body is incapable of metabolizing drugs.

2 Analysis of Cytochrome P450 (CYP450) enzyme is very important in predicting drug metabolism in an individual. Alterations in CYP450 affect the breakdown of drugs in the liver. The presence of a very active form of CYP450 enzyme indicates that the patient has a rapid rate of drug metabolism. The presence of a less active form of CYP450 indicates that the patient has a slow rate of drug metabolism. The presence of a very active form of CYP450 enzyme does not indicate that the patient has normal drug metabolism or is incapable of metabolizing drugs. Text Reference - p. 198

A nurse is caring for a patient with breast cancer. The patient asks the nurse about the genetic basis of the disease. How should the nurse describe the gene that may initiate conversion of normal cells to cancer cells? 1 Genome 2 Oncogene 3 Dominant allele 4 Recessive allele

2 Oncogene is the gene that can initiate conversion of normal cells to cancer cells. Genome refers to the entire genetic information contained in the human cell. Dominant allele is the gene that is expressed in the phenotype of a heterozygous individual. Recessive allele is the allele that has no noticeable effect on the phenotype of a heterozygous individual. Text Reference - p. 191

A patient has been advised to undergo genetic testing to determine the correct dosing of warfarin (Coumadin) prescribed for deep vein thrombosis. The nurse informs the patient that testing would be done for: 1 BRCA1 2 CYP2C9 3 HLA-B*5701 4 BRAF V600E

2 The patient would be tested for genetic variants of CYP2C9. This gene is responsible for an individual's sensitivity to warfarin. Alteration in the gene can make the enzyme more active or less active. Individuals with a less active form of the enzyme metabolize the drug slowly, making most of the drug bioavailable. Standard doses in these individuals may lead to an overdose. Individuals with the more active form of the enzyme tend to metabolize the drug faster, making it less bioavailable. Such individuals may need higher doses of warfarin to prevent clots from forming. BRCA1 is a gene mutation associated with breast cancer. HLA-B*5701 is associated with hypersensitivity reactions. BRAF V600E is associated with melanoma. STUDY TIP: Determine whether you are a "lark" or an "owl." Larks, day people, do best getting up early and studying during daylight hours. Owls, night people, are more alert after dark and can remain up late at night studying, catching up on needed sleep during daylight hours. It is better to work with natural biorhythms than to try to conform to an arbitrary schedule. You will absorb material more quickly and retain it better if you use your most alert periods of each day for study. Of course, it is necessary to work around class and clinical schedules. Owls should attempt to register in afternoon or evening lectures and clinical sections; larks do better with morning lectures and day clinical sections. Text Reference - p. 198

A nurse is explaining the Human Genome Project to a group of people in a community clinic. What were the purposes of this project? Select all that apply. 1 To eradicate genetic disorders 2 To allow for earlier detection of genetic disorders 3 To cure various genetic and congenital disorders 4 To promote better diagnosis of diseases 5 To determine an individual's risk for developing genetic diseases

2, 4, 5 The Human Genome Project, which mapped the entire human genome, was completed in 2003. The acquired information helped the medical community detect genetic disorders earlier, diagnose diseases better, and assess the risk of an individual developing genetic disorders. This information did not eradicate or cure genetic and congenital disorders. Text Reference - p. 194

A nurse is caring for a patient with Down syndrome and recalls that the patient has what chromosomal abnormality? 1 Trisomy 22 2 Trisomy 23 3 Trisomy 21 4 Trisomy 9

3 Chromosomal disorders are caused by structural changes within the chromosomes or by an excess or deficiency of the genes that are located on the chromosomes. Down syndrome is a chromosomal disorder. It is caused by an extra copy of chromosome 21 (called trisomy 21). Down syndrome is not caused by Trisomy of chromosomes 22, 23, and 9. Text Reference - p. 195

The nurse recalls that which structures or cells in the human body contain only a single copy of each chromosome? 1 Red blood cells 2 Stem cells 3 Oocytes 4 Hair follicles

3 Chromosomes are generally present in the cells in pairs, whereas oocytes and sperm contain only a single copy of each chromosome. Red blood cells, stem cells, and hair follicle cells have a duplicate of each chromosome in their nucleus. Text Reference - p. 192

The parents of a child diagnosed with cystic fibrosis ask the nurse what happened to cause this disease. What is the best response by the nurse? 1 It is X-linked so it was passed to the child from the mother. 2 It is a chromosome disorder that usually skips a generation. 3 It is autosomal recessive so both copies of the gene are abnormal. 4 It is autosomal dominant so the abnormal gene allele is expressed instead of the normal allele.

3 Cystic fibrosis is an autosomal recessive disorder, which means both of the genes in the pair on the chromosome are abnormal. Cystic fibrosis is not X-linked, from a chromosome disorder, or autosomal dominant. Text Reference - p. 195

A nurse is completing research studies on epigenetics. Why might the nurse study this subject? 1 To understand the role of genes in inheritance. 2 To understand the variability of drug responses in relation to variations in genes. 3 To understand how different environmental factors influence the expression of a gene. 4 To understand how genes interact with each other and influence the traits of an individual.

3 Epigenetics is the study of variations in the expression of gene function that do not involve a change in the DNA sequence. Epigenetics help us understand how environmental factors alter the way genes express. Genetics is the study of genes and their role in inheritance. Pharmacogenetics is the study of the variability of drug responses in relation to variations in genes. Genomics is the study of how genes interact with each other and influence the traits of an individual. Text Reference - p. 194

A nursing student has been asked to explain the term "genome" in a genetics class. Which statement is correct? 1 Genome is the study of genes. 2 Genome refers to the physical characteristics that one inherits. 3 Genome is the entire genetic constitution of an individual. 4 Genome refers to the set of chromosome excluding the sex chromosomes.

3 Genome is the entire genetic information contained in a human cell. Genetics is the study of genes. Traits are the physical characteristics that one inherits. The chromosomes other than the sex chromosomes are called autosomes. Text Reference - p. 191

A nurse is assessing an athlete who has come for a routine medical check-up. The patient has a family history of heart disease. The patient asks the nurse, "Can I get heart disease too?" What would be the most appropriate response by the nurse? 1 "You are physically fit; you will never have heart disease." 2 "You will have heart disease in the future, as this disease is prevalent in your family." 3 "You could have heart disease especially if you don't have a healthy lifestyle." 4 "You and your siblings will not have heart disease, but your children may have heart disease in the future."

3 Heart disease is a multifactorial genetic disorder. Other factors, such as physical activity and diet, also play an equally important role in the development of heart disease. Genetic predisposition increases an individual's risk of acquiring heart disease. The patient is an athlete so probably is physically fit, but the nurse cannot predict that the patient will not have heart disease in the future. Similarly, a family history of heart disease does not confirm that the individual will develop heart disease. The nurse cannot predict whether the patient's generation or the next generation will have heart disease. Text Reference - p. 194

A patient with hemophilia comes to the clinic for his general health check-up. He tells the nurse that he is planning to start a family. The patient asks, "Do I need to take any precautions to prevent my child from acquiring this disease?" Which is the most appropriate nursing response? 1 "No specific precautions need to be taken; your child will not get this disease from you." 2 "Hemophilia is not a genetic disorder; it cannot be passed on from one generation to another." 3 "Your female partner should be checked to see if she is a carrier of the same disorder." 4 "You should take specific medications to prevent your child from being affected by this disorder."

3 Hemophilia is an X-linked recessive disorder. If the male has this condition and the female partner is a carrier of the genetic mutation causing hemophilia, the child will have hemophilia, too. Therefore, it is extremely important to check whether the female partner is a carrier. Hemophilia is a genetic disease and can pass from one generation to another. Taking specific medications will not reduce the chances of the child inheriting hemophilia. Text Reference - p. 193

A patient tells the nurse, "My doctor mentioned that I am homozygous for a certain gene. What exactly does that mean?" The nurse will explain that it means that the patient: 1 Is affected by the genetic disorder. 2 Is not a carrier for a genetic disorder. 3 Has two identical alleles for the gene. 4 Has two different alleles for the gene.

3 Homozygous means having two identical alleles for one given gene, one inherited from each parent. Heterozygous means the individual has two different alleles for one given gene. Homozygous does not mean the patient is affected by the genetic disorder or that the patient is not a carrier for the disorder. It also does not indicate that the patient has two different alleles for the gene (the patient has two identical alleles). Text Reference - p. 191

A nurse is working in a gene therapy unit. The nurse has been asked by the health care provider to assist in administering a vector into a patient. Which route of administration would most likely be used? 1 Oral route 2 Inhalational route 3 Intravenous route 4 Percutaneous route

3 In gene therapy, vector refers to the carrier molecule that delivers the therapeutic gene to the patient's target cells. The vector may be injected directly into the target organ or given intravenously. Oral, inhalational, and percutaneous routes are not useful for introducing the vector into a patient's body. Text Reference - p. 199

A nurse is caring for a patient who is in the seventh month of pregnancy. The patient voices concern that her child may have a genetic disorder. The patient wishes to have the baby genetically tested immediately after birth. Which genetic test should the nurse suggest? 1 Parental testing 2 Predictive testing 3 Newborn screening 4 Prenatal diagnostic testing

3 Newborn screening is done in newborn babies to determine if they have a predisposition to any genetic disorders later in life. Parental testing is done to establish relationships between people. Predictive testing helps an individual learn if he or she is predisposed to a disease. Prenatal diagnostic testing is performed before delivery of the baby. Text Reference - p. 196

The patient has late stage non-small cell lung cancer. The health care provider is considering using crizotinib (Xalkori) for this patient. What should be done before it is prescribed for the patient? 1 Give chemotherapy first 2 Test for hypersensitivity to this drug 3 Test for the abnormal anaplastic lymphoma kinase (ALK) gene 4 Test for gene abnormalities that will affect the appropriate dose

3 Pharmacogenetics shows that an abnormal ALK gene in the patient with late-stage non-small cell lung cancers causes the cancer to develop and grow. Crizotinib works by blocking certain proteins called kinases, including the protein produced by the abnormal ALK gene. This drug interacts with many other drugs, so the patient's medications should be reviewed as well. TEST-TAKING TIP: Note the number of questions and the total time allotted for the test to calculate the times at which you should be halfway and three-quarters finished with the test. Look at the clock only every 10 minutes or so. Text Reference - p. 199

A woman with ovarian cancer would like to know which kind of genetic testing could help prevent her daughters from getting ovarian cancer. What should the nurse tell this patient? 1 Forensic testing 2 Carrier screening 3 Predictive testing 4 Prenatal diagnostic testing

3 Predictive genetic testing can be done to find mutated BRCA1 or BRCA2 genes. People who have these genetic mutations can elect to have a prophylactic oophorectomy to prevent the development of the cancer. Diagnostic testing also can identify genetic conditions. Forensic testing is done to identify an individual for legal purposes. Carrier screening identifies an unaffected individual who carries one copy of a specific gene and could pass it to next generations. Prenatal diagnostic genetic testing is done to detect changes in genes or chromosomes of a fetus before birth. STUDY TIP: Establish your study priorities and the goals by which to achieve these priorities. Write them out and review the goals during each of your study periods to ensure focused preparation efforts. Text Reference - p. 196

A patient with hemophilia presents to the health care facility for preconception counseling. He expresses concern about having a child with the same disease. His wife is healthy and not a carrier of hemophilia. What is true regarding this patient's offspring? 1 His son would be healthy. 2 His son would have the disease. 3 His daughter would be a carrier. 4 His daughter would have the disease.

3 The daughter would be a carrier of hemophilia. Hemophilia is an X-linked recessive disorder; therefore, affected individuals are usually males, given the fact that they have only one X chromosome. The daughters of an affected male and healthy female are carriers, as they have two X chromosomes--one from the mother, another from the father. The son of an affected male and a healthy female would be a carrier, as he inherits the healthy Y chromosome from the father and the healthy X chromosome from the mother. The son of the affected male would have the disease only if the mother is also a carrier. Text Reference - p. 193

A 5-year-old girl was diagnosed with type 1 diabetes mellitus. The mother says that no one else in her family has diabetes, and asks why her daughter would get it. How should the nurse explain this complex disease? 1 It is a congenital disorder that she was born with. 2 It is a single gene disorder, meaning only one gene mutation caused the disease. 3 It is a multifactorial genetic disorder caused by one or more genes and environmental factors. 4 It was an acquired genetic mutation, meaning she developed it, but her children will not have it.

3 Type 1 diabetes mellitus is a multifactorial genetic disorder related to one or more gene mutations and potentially various environmental factors that alter the way the gene(s) work. Type 1 diabetes is not a congenital disorder, a single gene disorder, nor an acquired genetic mutation. TEST-TAKING TIP: Stay away from other nervous students before the test. Stop reviewing at least 30 minutes before the test. Take a walk, go to the library and read a magazine, listen to music, or do something else that is relaxing. Go to the test room a few minutes before class time so that you are not rushed in settling down in your seat. Tune out what others are saying. Crowd tension is contagious, so stay away from it. Text Reference - p. 194

A man has an X-linked recessive disorder; his wife has a normal genotype. He asks the nurse, "Will this disorder be passed to my children?" Which answer is correct? 1 "Your male children will be carriers of this disorder." 2 "All of your children will be carriers of this disorder." 3 "Your female children will be carriers of this disorder." 4 "This genetic disorder will not be passed on to any of your children."

3 X-linked recessive disorders are caused by a mutation on the X chromosome. A normal female mating with an affected male will pass the carrier state to their female children only. Male children will be normal. See Table 13-2. Male children will not be carriers, they will be normal. Only female children are carriers; not all of the children will be affected. The nurse should not give false reassurance that the disorder will not be passed on to any of the children. Text Reference - p. 194

The concept of multifactorial genetic disorders is discussed during a class session about genetic disorders. What characterizes multifactorial genetic disorders? Select all that apply. 1 Genetic testing available for most multifactorial disorders. 2 They commonly are caused by single gene alterations. 3 Multifactorial conditions include diabetes mellitus, obesity, and cancer. 4 Caused by a combination of genetic and environmental factors. 5 These disorders commonly are related to X-linked disorders.

3 & 4 Multifactorial inherited conditions are caused by a combination of genetic and environmental factors. These disorders run in families but do not show the same inherited characteristics as the single gene mutation conditions. Multifactorial conditions include diabetes mellitus, obesity, hypertension, cancer, and coronary artery disease. They are not related to X-linked disorders, and genetic testing generally is not available for multifactorial disorders. Text Reference - p. 194

A patient is recently diagnosed with thalassemia. What information should the nurse include when teaching the patient about the disease? Select all that apply. 1 It is an X-linked recessive genetic disorder. 2 There is always a strong family history of the disease. 3 Males and females are affected equally with the disease. 4 Patients who are heterozygotes are carriers and usually have no symptom of the disease. 5 Children of two heterozygous parents have a 25% chance of being affected.

3, 4, 5 The nurse should inform the patient that thalassemia affects males and females equally. Heterozygotes are the carriers and are not affected by the disease and have no symptoms. Children born to two heterozygous parents have a 25% chance of being affected. Thalassemia is not an X-linked disorder; it is an autosomal recessive disorder. In most people with thalassemia, there is no family history suggestive of the disease. STUDY TIP: Begin studying by setting goals. Make sure they are realistic. A goal of scoring 100% on all exams is not realistic, but scoring an 85% may be a better goal. Text Reference - p. 193

A couple is adopting a baby girl. What health information related to the baby's biologic parents will be most useful to the parents and the baby as she grows up? 1 The grandmother had breast cancer. 2 The family has a history of Alzheimer's disease. 3 The family has an individual with Down's syndrome. 4 The family has familial adenomatous polyposis (FAP).

4 Because familial adenomatous polyposis occurs in those with the gene, being able to screen, monitor, and treat this baby will save her life in the long run. Breast cancer may or may not occur if the BRCA 1 or 2 are mutated. Many people who are positive for Apo E-4 do not develop Alzheimer's disease. Down's syndrome results from a chromosomal alteration and not a mutated gene. TEST-TAKING TIP: Get a good night's sleep before an exam. Staying up all night to study before an exam rarely helps anyone. It usually interferes with the ability to concentrate. Text Reference - p. 195

A nurse is working in a forensic laboratory and assisting a research professional with DNA finger printing. The nurse will find chromosomes in which part of the cell? 1 In the serum of blood 2 In the mitochondria 3 In the cytoplasm 4 In the nucleus

4 Chromosomes are located in cells, not outside cells. In a cell, chromosomes are found in the nucleus. Serum of the blood, mitochondria, and cytoplasm of the cell do not contain chromosomes in pairs. Serum of the blood is an acellular fluid. Mitochondria and cytoplasm are the organelles of a cell and do not have chromosomes in them. Text Reference - p. 191

The nurse is reviewing the concept of genetic mutations. Which of these is an example of germline mutation? 1 An error that occurs during DNA replication. 2 DNA damage after receiving chemotherapy. 3 DNA damage from exposure to cigarette toxins. 4 A mutation that is passed from a parent to a child.

4 Gene mutations primarily occur in two ways: inherited from a parent (germline mutation) or acquired (somatic) mutation during a person's lifetime. Acquired mutations can occur if a mistake is made as DNA replicates during cell division or environmental factors alter the DNA. A germline mutation is not an error that occurs during DNA replication. It is not DNA that is damaged following chemotherapy or from cigarette toxins. Text Reference - p. 193 STUDY TIP: In the first pass through the exam, answer what you know and skip what you do not know. Answering the questions you are sure of increases your confidence and saves time. This is buying you time to devote to the questions with which you have more difficulty.

A nurse is caring for a patient with Huntington's disease. This condition had been prevalent in the patient's family for the past five generations. The patient has two sons, both above the age of 40, and they do not show any signs or symptoms of Huntington's disease. Which term should be used to explain this genetic phenomenon? 1 X-linked disorder 2 Somatic mutation 3 Variable expression 4 Incomplete penetrance

4 Huntington's disease is a type of autosomal dominant disorder that is usually transmitted from one generation to the next. Sometimes these disorders skip a generation. Such a phenomenon is known as incomplete penetrance. X linked disorders are genetic disorders that occur due to mutation in the X chromosome. Somatic or acquired mutations do not follow an inheritance pattern. These mutations can occur if there is a mistake during the replication of the DNA or if there are changes in the environment that may alter the DNA. Variable expression is a characteristic of autosomal dominant disorders, where the same mutation is expressed in different ways in different people. Text Reference - p. 193

A couple is receiving genetic counseling. The father has Huntington's disease; the mother has a normal genotype. The nurse can tell the parents that 1 Their children will be carriers of Huntington's disease. 2 If their child is a boy, he will have Huntington's disease. 3 If their child is a girl, she will not develop Huntington's disease. 4 There is a 50% chance that their children will have Huntington's disease

4 If the mother has a normal genotype and the father has Huntington's disease, there is a 50% chance that offspring will have the disease. See Figure 13-9. If the child is a boy, it does not necessarily mean he will definitely have Huntington's disease. A female child is still at risk of developing the disease. The children have an equal risk of becoming carriers of the disease. Text Reference - p. 193

A nurse plans to assist with a genome-wide association study. What kinds of participants are needed for the study? 1 Men with a disease and women with a different disease 2 Men with a disease and women with a similar disease 3 Adults with a disease and children with a similar disease 4 Some people with a disease and similar people without the disease

4 In order to carry out a genome-wide association study (GWAS), researchers broadly use two groups of participants. The first group comprises people who are affected by the disease and are used for study. The other group includes similar people without the disease. Such a study helps to compare the various factors and consequences related to the genetic disease. Using men with a disease and women with a different disease does not help in this comparison. Using men and women with similar diseases may result in gender-biased results. Adults and children cannot be compared because of the physiological differences between the two. Text Reference - p. 191

A patient who is employed is diagnosed with a genetic disorder that will make the skeletal muscles get progressively weaker. What is a priority nursing action? 1 Inform family members about the patient's disorder. 2 Inform the patient's employer about the condition for a request for medical leave. 3 Inform the insurance company to obtain financial help for the treatment. 4 Inform the patient about the Genetic Information Nondiscrimination Act (GINA).

4 When a person is diagnosed with a genetic problem, the nurse should be very careful in sharing the patient's information, taking into consideration the ethical, social, and cultural background of the person. The patient should be informed about the patient's rights related to genetic information. The patient should be informed about the Genetic Information Nondiscrimination Act (GINA). Without the patient's consent, the patient's medical information should not be shared with anyone, including the patient's family members, employer, and the insurance company. Text Reference - p. 201

A nurse recalls that a human cell has autosomes and sex chromosomes. How many pairs of autosomes are present in the human cell? 1 20 pairs 2 22 pairs 3 23 pairs 4 24 pairs

A normal human cell consists of 22 pairs of homologous chromosomes or autosomes. In total, a normal human cell has 23 pairs of chromosomes — 22 pairs of autosomes and a pair of sex chromosomes. Having 20, 23, or 24 pairs of autosomes is indicative of a genetic abnormality in humans. Text Reference - p. 191

After genetic counseling and testing, a patient is found positive for the apolipoprotein E-4 (Apo E-4) allele. What should the nurse explain to the patient regarding these results? 1 The patient has a family history of Alzheimer's disease. 2 The patient has risk of developing Alzheimer's disease. 3 The patient will definitely develop Alzheimer's disease. 4 The patient can prevent development of Alzheimer's disease.

A positive result for an Apo E-4 allele indicates that the patient is at risk of developing Alzheimer's disease. It is not a confirmatory test. Even in the presence of the Apo E-4, some people do not develop the disease. The test is not indicative of a family history, as the mutation can be acquired. In addition, it also does not indicate that the disease is preventable. TEST-TAKING TIP: Because few things in life are absolute without exceptions, avoid selecting answers that include words such as always, never, all, every, and none. Answers containing these key words are rarely correct. Text Reference - p. 197

A patient has been found to test positive for a genetic mutation. The nurse recognizes that which of these statements is true? Select all that apply. 1 The laboratory found an alteration in a gene. 2 The genetic disease will become severe in the patient's lifetime. 3 The patient may have an increased risk of developing a genetic disease. 4 Other family members are not at risk for developing a genetic disease. 5 The patient should not have any children or any additional children

A positive test result means that the laboratory found a change in a particular gene, chromosome, or protein that was being tested. Depending on the purpose of the test, this result may confirm a diagnosis (e.g., Huntington's disease), indicate that a person is a carrier of a particular genetic mutation (e.g., cystic fibrosis), identify an increased risk of developing a disease (e.g., breast cancer), or suggest a need for further testing. In addition, a positive test cannot predict the course or severity of a condition. There is no indication the disease will become severe. Other family members could also be at risk of developing the disease. There is nothing to indicate the patient should not have children. Text Reference - p. 10

A specimen of adult stem cells is to be obtained from a patient for culture. The nurse provides the patient with information about adult stem cells. Which statement would be appropriate for the nurse to include? 1 "Adult stem cells can be used to cure any disease." 2 "Adult stem cells can be used to regenerate any tissue." 3 "Adult stem cells can be obtained only on day 4 of embryonic development." 4 "Adult stem cells can regenerate or repair tissues from which they are obtained."

Adult stem cells can be used to regenerate only those tissues from which they are obtained; for example, stem cells from liver can be used only to regenerate liver. Stem cell therapy cannot be used to cure all possible diseases. Embryonic stem cells can be used to regenerate any tissue and can be obtained on the 4th or 5th day of embryonic development. Text Reference - p. 200

A nurse is studying the genetic test report of a patient. The test reveals the presence of a mutated BRCA1 gene. How should the nurse explain the test result to the patient? 1 "You have breast cancer. You may need to get one or both breasts removed." 2 "You are at risk of developing breast cancer. You should seek advice from an oncologist." 3 "You do not have breast cancer but your daughters may have breast cancer in the future." 4 "Your husband needs to be tested for the presence of BRCA1 gene."

The presence of the BRCA1 and/or BRCA2 gene significantly increases an individuals' risk of developing breast cancer. The nurse should suggest the patient seek advice from an oncologist. The presence of the BRCA1 gene does not confirm the presence of breast cancer. The test result does not confirm the absence of the cancer, nor does it suggest that the patient's daughters may have breast cancer. Asking the patient to get her husband tested for the presence of the BRCA1 gene is not an appropriate response to this test result. Text Reference - p. 194

Both parents of a child with cystic fibrosis are found to be heterozygous carriers for cystic fibrosis. Considering that it is an autosomal recessive disorder, what are the chances of the second baby being affected with cystic fibrosis? Fill in the blank using a whole number. ___%

There is a 25% chance of the second baby being affected with cystic fibrosis. Both parents are carriers (heterozygotes) and carry only one mutated allele. Since cystic fibrosis has an autosomal recessive pattern of inheritance, there is a 25% chance that the second baby would be born with the disease. There is a 25% chance that the baby would be normal and a 50% chance that the baby would be a carrier. The carriers carry one allele for cystic fibrosis and may not be affected by the disease, meaning they may be asymptomatic. Text Reference - p. 193