MIDTERM FINAL CHAPTER 10: Genetic Disorders and Prenatal Screening Flashcards
Which of the following conditions is an example of an autosomal recessive disorder?
A. Huntington disease
B. Neurofibromatosis
C. Tay–Sachs disease
D. Marfan syndrome
C. Tay–Sachs disease
Rationale: Tay–Sachs disease is an autosomal recessive disorder requiring two copies of the mutant gene for expression. Huntington disease (A), neurofibromatosis (B), and Marfan syndrome (D) are autosomal dominant conditions.
A family has one child with sickle cell disease and is planning to have another child. Both parents are carriers. Which of the following statements should the nurse include when discussing the inheritance pattern? (Select all that apply)
A. “Each pregnancy has a 25% chance of the child having sickle cell disease.”
B. “Each pregnancy has a 50% chance of the child being a carrier.”
C. “Each pregnancy has a 50% chance of the child having sickle cell disease.”
D. “Each pregnancy has a 25% chance of the child being unaffected.”
E. “Sickle cell disease affects males and females equally.”
A. “Each pregnancy has a 25% chance of the child having sickle cell disease.”
B. “Each pregnancy has a 50% chance of the child being a carrier.”
D. “Each pregnancy has a 25% chance of the child being unaffected.”
E. “Sickle cell disease affects males and females equally.”
Rationale: In autosomal recessive inheritance, each pregnancy has a 25% chance of the child inheriting two abnormal genes and having the disorder (A), a 50% chance of being a carrier (B), and a 25% chance of being unaffected (D). Since the inheritance is not sex-linked, males and females are equally affected (E).
Which of the following is a primary purpose of genetic counseling?
A. Diagnosing and treating genetic diseases in clients and families.
B. Reducing pregnancy risks and establishing early prenatal care.
C. Providing genetic testing to all pregnant women regardless of their history.
D. Identifying and communicating genetic risks to families.
D. Identifying and communicating genetic risks to families.
Rationale: Genetic counseling aims to provide families with information about genetic risks, including potential conditions and management options. While reducing pregnancy risks (B) and prenatal care are part of preconception counseling, genetic counseling extends beyond this to include evaluation and support for genetic conditions.
The nurse is explaining genetic counseling to a client who is planning a pregnancy. Which statement by the nurse requires correction?
A. “Genetic counseling only applies to individuals with a family history of genetic disorders.”
B. “Genetic counseling can confirm, diagnose, or rule out a genetic condition.”
C. “It is ideal to have genetic counseling before conception occurs.”
D. “A detailed family history and pedigree are important parts of genetic counseling.”
A. “Genetic counseling only applies to individuals with a family history of genetic disorders.”
Rationale: Genetic counseling is not limited to individuals with a family history of genetic disorders. It may also be beneficial for couples planning a family, those with a history of congenital anomalies, or suspected teratogen exposure.
Which scenario would most likely require urgent genetic counseling?
A. A couple planning their first pregnancy with a history of teratogen exposure.
B. A child diagnosed prenatally with a life-threatening genetic disease.
C. A family history of a genetic disorder in a couple planning to conceive.
D. A diagnosis of a genetic disorder in a client’s extended family.
B. A child diagnosed prenatally with a life-threatening genetic disease.
Rationale: Urgent genetic counseling is needed in situations where immediate decisions, such as continuation or termination of pregnancy, must be made due to the diagnosis of a life-threatening condition.
When gathering a family history for genetic counseling, which action is most appropriate?
A. Limiting the history to immediate family members only.
B. Requesting medical records only for family members currently alive.
C. Informing families in advance about the need for detailed and sensitive information.
D. Gathering information only for individuals who have genetic disorders.
C. Informing families in advance about the need for detailed and sensitive information.
Rationale: Informing families about the need for detailed information allows them time to collect necessary facts and prepare for sensitive discussions. A detailed family history typically includes three generations and may require information beyond immediate family members.
Which of the following is an ethical consideration in genetic counseling?
A. Recommending termination of a pregnancy when a genetic disorder is identified.
B. Avoiding discussions about disorders that have no prenatal screening tests available.
C. Encouraging genetic testing for all couples regardless of their preferences.
D. Maintaining client autonomy by presenting information nonjudgmentally.
D. Maintaining client autonomy by presenting information nonjudgmentally.
Rationale: A key ethical principle in genetic counseling is respecting client autonomy and presenting information in a nonjudgmental and nondirective manner, allowing clients to make informed decisions based on their values.
What is the most appropriate time for genetic counseling?
A. During the second trimester of pregnancy.
B. At the time of delivery to prepare for newborn care.
C. Before conception occurs.
D. Only when a genetic disorder is diagnosed in the family.
C. Before conception occurs.
Rationale: The ideal time for genetic counseling is before conception, allowing couples to plan for potential risks and establish prenatal care early.
Which of the following statements about the role of genetic counselors is true?
A. They analyze genetic data and communicate risks to families.
B. They determine whether a couple should proceed with a pregnancy.
C. They are primarily responsible for treating genetic disorders.
D. They only work with families who have existing genetic conditions.
A. They analyze genetic data and communicate risks to families.
Rationale: Genetic counselors are responsible for evaluating genetic risks, providing education, and offering support to families. They do not make decisions for the clients or focus solely on families with pre-existing conditions.
A client considering genetic counseling expresses concern about privacy. Which response by the nurse is most appropriate?
A. “Your privacy is guaranteed, and no information will be shared under any circumstances.”
B. “Confidentiality will be maintained, but sensitive information may emerge that requires discussion.”
C. “You should not worry about privacy because this process is routine for all families.”
D. “We will share the genetic results with other family members to help them prepare.”
B. “Confidentiality will be maintained, but sensitive information may emerge that requires discussion.”
Rationale: While confidentiality is critical in genetic counseling, clients should be aware that sensitive information (e.g., unknown parentage or adoption) may be revealed during the process.
What is an important nursing consideration when providing genetic counseling to a client from a culturally diverse background?
A. Recommending genetic testing based on the nurse’s understanding of their cultural risks.
B. Providing standardized genetic information regardless of cultural differences.
C. Maintaining sensitivity to cultural values while presenting information nondirectively.
D. Avoiding discussions about genetic conditions that may conflict with cultural beliefs.
C. Maintaining sensitivity to cultural values while presenting information nondirectively.
Rationale: Nurses must respect cultural values and beliefs while providing genetic counseling in a nondirective and culturally sensitive manner, ensuring the client feels supported in their decision-making process.
What is the purpose of combining first-trimester screening with second-trimester (quad screen) for women under 35?
A. To determine the exact genetic disorder affecting the fetus.
B. To improve detection rates of chromosomal abnormalities.
C. To eliminate the need for cell-free DNA testing.
D. To detect neural tube defects only.
B. To improve detection rates of chromosomal abnormalities
Rationale: Combining first-trimester and second-trimester screenings increases the accuracy of detecting chromosomal abnormalities such as Down syndrome.
Which components are included in a nuchal translucency screening?
A. Blood markers and assessment of the nasal bone.
B. Measurement of fetal fraction of DNA and nasal bone presence.
C. Cell-free DNA testing and second-trimester ultrasound.
D. MSAFP alone.
A. Blood markers and assessment of the nasal bone.
Rationale: Nuchal translucency screening combines blood markers with ultrasound findings, such as the presence or absence of the nasal bone, to assess the risk of chromosomal abnormalities.
Why are MSAFP or quad screen results less accurate when used alone compared to combined screening?
A. They lack the genetic component of fetal fraction DNA.
B. They do not account for first-trimester markers.
C. They are performed at the wrong gestational age.
D. They primarily detect maternal health issues.
B. They do not account for first-trimester markers.
Rationale: When used alone, these tests lack the complementary data provided by first-trimester markers, reducing their overall accuracy.
What does the “time-sensitive” label refer to in genetic screening?
A. The need for results before labor begins.
B. The urgency of counseling after abnormal findings.
C. The delay in results due to genetic analysis.
D. The requirement for screening within specific gestational windows.
D. The requirement for screening within specific gestational windows.
Rationale: Genetic screening tests must be performed at specific gestational ages to ensure accurate results, as fetal development changes rapidly.
What is the significance of cell-free DNA testing for women over 35?
A. It reduces the need for invasive testing in high-risk pregnancies.
B. It detects neural tube defects more effectively than MSAFP.
C. It is more cost-effective than traditional screenings.
D. It guarantees the diagnosis of chromosomal abnormalities.
A. It reduces the need for invasive testing in high-risk pregnancies.
Rationale: Cell-free DNA testing is a noninvasive option with high accuracy for detecting chromosomal abnormalities, particularly in women over 35 who are at higher risk.
How does cell-free DNA testing use fetal fraction DNA to detect abnormalities?
A. By isolating maternal blood cells and analyzing their genetic composition.
B. By identifying DNA fragments released from the placenta into maternal blood.
C. By obtaining direct samples from the fetus through amniocentesis.
D. By measuring hormone levels in the maternal bloodstream.
B. By identifying DNA fragments released from the placenta into maternal blood.
Rationale: Fetal DNA fragments are analyzed from the maternal bloodstream to detect chromosomal abnormalities.
At what gestational age can cell-free DNA testing first be performed?
A. After 6 weeks of gestation.
B. After 10 weeks of gestation.
C. During the first trimester only.
D. After 20 weeks of gestation.
B. After 10 weeks of gestation.
Rationale: Cell-free DNA testing is reliable and can be performed starting at 10 weeks of gestation.
Which conditions have a 99.7% predictive value when using cell-free DNA testing?
A. Trisomy 13, Trisomy 18, Trisomy 21, and neural tube defects.
B. Trisomy 21, Trisomy 18, Trisomy 13, and sex chromosome abnormalities.
C. Turner syndrome and neural tube defects.
D. Chromosomal deletions and metabolic disorders.
B. Trisomy 21, Trisomy 18, Trisomy 13, and sex chromosome abnormalities.
Rationale: Cell-free DNA testing provides highly accurate predictions for these conditions, aiding in early decision-making and care planning.
What additional benefit does cell-free DNA testing provide beyond detecting chromosomal abnormalities?
A. It reveals fetal gender.
B. It identifies maternal genetic conditions.
C. It guarantees a healthy pregnancy outcome.
D. It detects teratogen exposure.
A. It reveals fetal gender.
Rationale: In addition to detecting chromosomal abnormalities, cell-free DNA testing can identify fetal gender based on the DNA fragments analyzed.
