A woman with Turner syndrome asks why she is unable to become pregnant. Which explanation is accurate?
Her ovaries do not mature because she has only one X chromosome
✓
She has an extra copy of the Y chromosome
A single-gene mutation blocks her hormone receptors
Her uterus is absent because of an extra X chromosome
Correct Answer
Her ovaries do not mature because she has only one X chromosome
Turner syndrome is a chromosomal condition in which a female has a single X chromosome, and her sexual organs do not mature, causing infertility. She has an extra copy of the Y chromosome is incorrect, because Turner syndrome involves a missing sex chromosome rather than an extra one. A single-gene mutation blocks her hormone receptors is incorrect, because the cause is a missing chromosome rather than one gene. Her uterus is absent because of an extra X chromosome is incorrect, because one X chromosome is missing, not added.
Category: Chromosomal Conditions
Question 2
Which factor most increases the chance of having a child with Down syndrome?
Older paternal age
Older maternal age
✓
A father with type 1 diabetes
A previous child with sickle cell disease
Correct Answer
Older maternal age
Down syndrome usually results from nondisjunction, and the risk rises as the mother ages because errors in chromosome separation become more likely in older eggs. Older paternal age matters much less, because nondisjunction is far less common in sperm. A father with type 1 diabetes does not raise the risk of an extra chromosome. A previous child with sickle cell disease reflects a single-gene recessive disorder and does not predict Down syndrome.
Category: Chromosomal Conditions
Question 3
The mutation that causes sickle cell disease substitutes one amino acid for another in the beta chain of hemoglobin. Which type of mutation is this?
Nonsense mutation
Frameshift mutation
Missense mutation
✓
Silent mutation
Correct Answer
Missense mutation
A missense mutation is a single base substitution that results in a different amino acid, which may change the protein; in sickle cell disease it alters hemoglobin. A nonsense mutation turns a codon into a stop signal and usually produces a shortened, nonfunctional protein. A frameshift mutation inserts or deletes bases so that every following amino acid changes. A silent mutation changes a base without changing the amino acid.
Category: Mutations
Question 4
A mutation arises in skin cells after long-term sun exposure and cannot be passed on to the person's children. Which term describes it?
Germline mutation
Inherited mutation
Gamete mutation
Somatic mutation
✓
Correct Answer
Somatic mutation
A somatic mutation arises in body cells after fertilization, can be caused by ultraviolet radiation or chemicals, and is not passed to offspring, although it can contribute to cancer. A germline mutation occurs in reproductive cells and can be passed to children. Inherited mutation describes a change received from a parent. Gamete mutation describes a change in an egg or sperm, which is germline rather than somatic.
Category: Mutations
Question 5
A couple who are both carriers of cystic fibrosis have one child with the disease. They ask whether their next child will be spared. Which response is accurate?
Each pregnancy has the same chance of an affected child
✓
The next child cannot be affected because one already is
Only daughters can be affected in later pregnancies
The next child will certainly be affected
Correct Answer
Each pregnancy has the same chance of an affected child
In autosomal recessive inheritance the chance of an affected child is the same for every pregnancy when both parents are carriers, regardless of earlier outcomes. The next child cannot be affected because one already is reflects a common misunderstanding, since each conception is independent. Only daughters can be affected in later pregnancies is incorrect, because the gene is on an autosome and affects both sexes. The next child will certainly be affected is incorrect, because the child may also be an unaffected carrier or not inherit the gene at all.
Category: Inheritance Patterns
Question 6
A woman is a carrier of hemophilia, an X-linked recessive disorder, and her partner is unaffected. Which statement about their children is accurate?
Daughters may be affected, and sons may be carriers
Sons may be affected, and daughters may be carriers
✓
All of the children will be carriers but none affected
The children cannot inherit the gene from their mother
Correct Answer
Sons may be affected, and daughters may be carriers
A son who receives the mother's X chromosome with the mutation has no second X to offset it and will be affected, while a daughter who receives it also gets a normal X from her father and becomes a carrier. Daughters may be affected, and sons may be carriers reverses the pattern; males cannot be carriers of X-linked recessive disorders. All of the children will be carriers but none affected ignores that sons can be affected. The children cannot inherit the gene from their mother is incorrect, because the mother passes one of her X chromosomes to every child.
Category: Inheritance Patterns
Question 7
A father has an X-linked dominant disorder, and the mother is unaffected. Which of their children will inherit the disorder?
All of his sons and none of his daughters
Sons and daughters equally
All of his daughters and none of his sons
✓
None of his children
Correct Answer
All of his daughters and none of his sons
A father passes his only X chromosome to every daughter and his Y chromosome to every son, so with an X-linked dominant disorder all daughters are affected and no sons are. All of his sons and none of his daughters reverses the pattern, since sons receive his Y chromosome. Sons and daughters equally describes an affected mother, who can pass the gene to children of either sex. None of his children is incorrect, because a dominant allele on his X chromosome reaches every daughter.
Category: Inheritance Patterns
Question 8
A parent with type AB blood and a parent with type O blood are expecting a child. Which blood types are possible for the child?
Type AB or type O
Type O only
Type AB only
Type A or type B
✓
Correct Answer
Type A or type B
The type AB parent passes either the A or the B allele, and the type O parent can pass only the recessive O allele, so the child will be type A or type B. Type AB or type O is not possible, because the child cannot receive both A and B or two O alleles from these parents. Type O only would require an O allele from each parent. Type AB only would require both A and B from one parent.
Category: Inheritance Patterns
Question 9
Huntington disease is caused by a dominant allele and is eventually fatal, yet the allele continues to be passed down in families. Why?
Symptoms often begin in middle age, after people may have had children
✓
The allele skips every other generation
Only relatives who never show symptoms pass it on
The allele is passed only from fathers to sons
Correct Answer
Symptoms often begin in middle age, after people may have had children
Because Huntington disease often appears in middle age, many people have already had children before they know they carry the allele, which allows a lethal dominant allele to persist. The allele skips every other generation is incorrect, because dominant disorders typically appear in every generation. Only relatives who never show symptoms pass it on is incorrect, because people who later develop the disease pass it on. The allele is passed only from fathers to sons describes Y-linked inheritance, not this autosomal disorder.
Category: Inheritance Patterns
Question 10
In a heterozygous person, a trait appears as a blend midway between the two homozygous forms. Which pattern of inheritance is this?
Codominance
Incomplete dominance
✓
X-linked dominance
Mitochondrial inheritance
Correct Answer
Incomplete dominance
In incomplete dominance the heterozygous phenotype is intermediate between the two homozygous phenotypes. Codominance means both alleles are fully expressed side by side, as in type AB blood, rather than blended. X-linked dominance describes a dominant allele carried on the X chromosome. Mitochondrial inheritance describes traits passed only through the mother's mitochondria.
Category: Inheritance Patterns
Question 11
Genetic testing confirms familial hypercholesterolemia in a patient. Which nursing action reflects a genomic approach to care?
Advise that diet changes will have no effect
Explain that relatives share no added risk
Encourage screening of the patient's close blood relatives
✓
Delay treatment until heart disease symptoms appear
Correct Answer
Encourage screening of the patient's close blood relatives
Familial hypercholesterolemia is inherited, so family-based screening finds relatives who can begin treatment early, before cardiovascular disease develops. Advising that diet changes will have no effect is incorrect, because individualized diet and exercise advice is part of management. Telling the patient that relatives share no added risk is incorrect, because blood relatives may carry the same mutation. Delaying treatment until heart disease symptoms appear defeats the purpose of early detection.
Category: Family History and Risk
Question 12
While taking a family history, which finding is a red flag for an inherited disorder?
A grandparent who developed cataracts in old age
A parent with knee osteoarthritis in late life
A sibling who broke an arm while skiing
A young relative who died suddenly of a cardiac cause
✓
Correct Answer
A young relative who died suddenly of a cardiac cause
Sudden, unexpected cardiac death, especially at a young age, is a red flag that suggests an inherited condition and warrants referral for genetic counseling. A grandparent who developed cataracts in old age reflects a common age-related change. A parent with knee osteoarthritis in late life is a common wear-related condition. A sibling who broke an arm while skiing is an injury, not a genetic pattern.
Category: Family History and Risk
Question 13
To complete a genetic family history, the nurse wants to review the medical records of the patient's relatives. What is required first?
Written consent from those relatives
✓
Verbal permission from the patient only
Approval from the patient's insurer
A request from the patient's employer
Correct Answer
Written consent from those relatives
Collecting a family history from the patient requires the patient's verbal consent, but obtaining information directly from relatives or their records requires discussion with those relatives and their written consent. Verbal permission from the patient only does not cover other people's records. Approval from the patient's insurer has no role in consent for another person's information. A request from the patient's employer is irrelevant and could raise concerns about genetic discrimination.
Category: Ethical and Legal Issues
Question 14
A patient has nonspecific signs such as poor muscle tone, and no single condition is suspected. Which type of genetic test is most suitable?
Single-gene testing
Panel testing
✓
Newborn screening
Carrier screening
Correct Answer
Panel testing
Panel testing examines a group of genes at once and is used when signs are nonspecific. Single-gene testing looks at one gene and fits when a specific condition, such as sickle cell disease, is suspected. Newborn screening is a population program performed shortly after birth. Carrier screening identifies the risk of passing an inherited disorder to a child rather than explaining the patient's own signs.
Category: Genetic Testing
Question 15
A couple planning a pregnancy wants to learn their risk of having a child with Tay-Sachs disease. Which test fits this goal?
Newborn screening
Tumor tissue testing
Carrier screening
✓
Pharmacogenetic testing
Correct Answer
Carrier screening
Carrier screening identifies people who carry a recessive allele and therefore their risk of having an affected child, which supports reproductive decision-making. Newborn screening tests infants after birth, not prospective parents. Tumor tissue testing looks for mutations in a cancer. Pharmacogenetic testing predicts how a person will respond to medications.
Category: Genetic Testing
Question 16
A patient's test identifies a mutation linked to an inherited cancer syndrome. The patient asks whether the result shows when cancer will develop and how severe it will be. Which response is accurate?
A positive result means cancer is already present
The test predicts both the age of onset and severity
A positive result means relatives cannot be affected
The test shows the gene change but cannot predict onset or severity
✓
Correct Answer
The test shows the gene change but cannot predict onset or severity
Diagnostic genetic testing can confirm a causative mutation but often cannot reveal when disease will begin or how severe it will be; the result guides risk-reduction and monitoring. A positive result means cancer is already present is incorrect, because the mutation raises risk rather than proving disease. The test predicts both the age of onset and severity overstates what testing can tell. A positive result means relatives cannot be affected is incorrect, because relatives may share the mutation.
Category: Genetic Testing
Question 17
A patient worries that an employer could fire her because of a positive genetic test result. Which federal law protects against this?
Genetic Information Nondiscrimination Act
✓
Health Insurance Portability and Accountability Act
Patient Self-Determination Act
Emergency Medical Treatment and Labor Act
Correct Answer
Genetic Information Nondiscrimination Act
The Genetic Information Nondiscrimination Act bars employers from using genetic information in employment decisions and bars health insurers from using it to decide coverage. The Health Insurance Portability and Accountability Act sets privacy rules for health information but does not address firing based on genetic results. The Patient Self-Determination Act concerns advance directives. The Emergency Medical Treatment and Labor Act requires emergency screening and stabilization.
Category: Ethical and Legal Issues
Question 18
A patient tests positive for an inherited cancer gene mutation but does not want the result shared with siblings. What should the nurse do?
Contact the siblings directly to warn them
Keep the result confidential and encourage the patient to consider telling them
✓
Send the result to the siblings' health care providers
Report the result to the state health department
Correct Answer
Keep the result confidential and encourage the patient to consider telling them
Genetic results are confidential, and disclosure to relatives without the patient's consent is allowed only in rare, narrowly defined circumstances that a nurse does not decide alone, so the nurse protects the result while supporting the patient's own decision to share it. Contacting the siblings directly to warn them breaches confidentiality. Sending the result to the siblings' health care providers is also an unauthorized disclosure. Reporting the result to the state health department is not required for a genetic test result.
Category: Ethical and Legal Issues
Question 19
A pregnant patient declines prenatal genetic testing because of her religious beliefs. What should the nurse do?
Explain that the testing is required by law
Ask her family to persuade her to be tested
Respect the decision and offer information without pressure
✓
Document that she is noncompliant with care
Correct Answer
Respect the decision and offer information without pressure
Nurses advocate for autonomous, informed and voluntary decisions and recognize that religious and cultural beliefs shape choices about genetic testing. Explaining that the testing is required by law is wrong, because prenatal genetic testing is voluntary. Asking her family to persuade her to be tested introduces coercion. Documenting that she is noncompliant with care mislabels an informed refusal.
Category: Ethical and Legal Issues
Question 20
Which is an example of a beneficial mutation?
A CFTR gene mutation that causes thick mucus
A DNA repair gene mutation that raises colon cancer risk
A gene mutation that causes nerve tumors
A CCR5 gene deletion that blocks HIV from entering cells
✓
Correct Answer
A CCR5 gene deletion that blocks HIV from entering cells
A deletion in the CCR5 gene removes a receptor that HIV uses to enter cells, greatly reducing susceptibility in people who inherit it from both parents. A CFTR gene mutation that causes thick mucus produces cystic fibrosis. A DNA repair gene mutation that raises colon cancer risk describes Lynch syndrome. A gene mutation that causes nerve tumors describes neurofibromatosis, a harmful autosomal dominant disorder.
Category: Mutations