Genetics
A woman asks the obstetrician's nurse about cord blood banking. Which of the following responses by the nurse would be best? A. "I think it would be best to ask the doctor to tell you about that." B. "The cord blood is frozen in case your baby develops a serious illness in the future." C. "The doctors could transfuse anyone who gets into a bad accident with the blood." D. "Cord blood banking is very expensive and the blood is rarely ever used."
B This statement is correct. The baby's umbilical cord blood is kept by a cord blood bank to be used if and when the baby should develop a serious illness such as leukemia.
A client has just had an amniocentesis to determine whether her baby has an inheritable genetic disease. Which of the following interventions is highest priority at this time? A. Assess the fetal heart rate B. Check the client's temperature C. Acknowledge the client's anxiety about the possible findings D. Answer questions regarding the genetic abnormality
A Assessing the fetal heart rate is the highest priority since, although rare, the fetus may have been injured during the procedure.
During a genetic evaluation, it is discovered that the woman is carrying one autosomal dominant gene for a serious late adult-onset disease, while her partner's history is unremarkable. Based on this information, which of the following family members should be considered high risk and in need of genetic counseling? (Select all that apply) A. The woman's fetus B. The woman's sisters C. The woman's brothers D. The woman's parents E. The woman's partner
A,B,C,D -The woman's fetus has a 1 in 2, or 50% probability of having the gene. -The woman's sisters have a 1 in 2, or 50%, probability of having the gene. -The woman's brothers have a 1 in 2, or 50%, probability of having the gene. -One of the woman's parents definitely has the gene. Since the age of onset can be as late as age 50, the parents' symptoms may not yet have appeared.
A woman has been advised that the reason she has had a number of spontaneous abortions is because she has an inheritable mutation. Which of the following situations is consistent with this statement? A. A client developed skin cancer after being exposed to the sun. B. A client developed colon cancer from an inherited dominant gene. C. A client's genetic analysis report revealed a reciprocal translocation. D. A client's left arm failed to develop when she was a fetus.
C A reciprocal translocation can result in infertility.
Most children born into families look similar but are not exactly the same. The children appear different because homologous chromosomes exchange genetic material at which of the following? A. Centromere B. Chiasma C. Chromatid D. Codon
B A chiasma is the site where crossing over between nonsister chromatids takes place. At this site, genetic material is swapped between the chromatids.
A 3-month-old baby has been diagnosed with cystic fibrosis (CF). The mother says, "How could this happen? I had an amniocentesis during my pregnancy and everything was supposed to be normal!" What must the nurse understand about this situation? A. Cystic fibrosis cannot be diagnosed by amniocentesis B. The baby may have an uncommon genetic variant of the disease C. It is possible that the laboratory technician made an error D. Instead of obtaining fetal cells, the doctor probably harvested maternal cells
B This response is likely. The genetic tests that are performed check only for the most common genetic variants of many diseases, including CF. If the baby were positive for an uncommon variant, it would be missed.
A woman, who has undergone amniocentesis, has been notified that her baby is XX with a 14/21 robertsonian chromosomal translocation. The nurse helps the woman to understand which of the following? A. The baby will have a number of serious genetic defects B. It is likely that the baby will be unable to have children when she grows up. C. Chromosomal translocations are common and rarely problematic D. An abortion will probably be the best decision under the circumstances
B Because there is a translocation in the child's chromosomal pattern, the child's gametes will likely contain an abornormal amount of genetic material and the child will likely be infertile.
A man has inherited the gene for familial adenomatous polyposis (FAP), an autosomal dominant disease. He and his wife wish to have a baby. Which of the following would provide the couple with the highest probability of conceiving a healthy child? A. Amniocentesis B. Chorionic villus sampling C. Preimplantation genetic diagnosis D. Gamete intrafallopian transfer
C Preimplantation genetic diagnosis will provide the couple with the highest probability of conceiving a healthy child.
A 10-week gravid states that her sister's son has been diagnosed with an X-linked recessive disease, Ducheene muscular dystrophy. She questions the nurse about the disease. Which of the following responses is appropriate for the nurse to make? A. "Because Duchenne muscular dystrophy is inherited through the woman, it is advisable for you to see a genetic counselor." B. "Duchenne muscular dystrophy usually occurs as a spontaneous mutation, It is very unlikely that your fetus is affected." C. "Your child could acquire Duchenne muscular dystrophy only if both you and your husband carried the gene. You need to chick your husband's family history." D. "If you were to have an amniocentesis and it were to be positive for Duchenne muscular dystrophy, I could refer you to an excellent abortion counselor."
A Because Duchenne muscular dystrophy is X-linked, if her sister is a carrier, she too may be a carrier. She should see a genetic counselor.
A client, 11 weeks' gestation, is preop for chorionic villus sampling (CVS). The woman is very anxious that the baby will be injured during the procedure. Which of the following statements would be appropriate for the nurse to make? A. "It is unlikely that the baby will be injured because before inserting the needle, the doctor will locate the baby and placenta using ultrasound." B. "I know how you feel. Every time I assist with the procedure I say a little prayer that the baby won't be hurt." C. "Has your doctor told you about all of the possible complications that can happen during the procedure?" D. "I understand how you feel, but you know how important it is to find out whether your baby has a genetic disease or not."
A This statement is correct. It is unlikely that the baby will be injured because, before inserting the needle, the doctor will locate the products of conception using ultrasound.
The nurse is creating a pedigree from a client's family history. Which of the following symbols should the nurse use to represent a female? A. Circle B. Square C. Triangle D. Diamond
A The circle is the symbol used to represent the female.
Once oogenesis is complete, the resultant gamete cell contains how many chromosomes? A. 23 B. 46 C. 47 D. 92
A The haploid number of chromosomes is 23, the normal number of chromosomes in the gamete - in this case, in the ovum.
A woman is a carrier for hemophilia A, an X-linked recessive illness. Her husband has a normal genotype. The nurse can advise the couple that the probability that their daughter will have the disease is: A. 0% probability B. 25% probability C. 50% probability D. 75% probability
A The probability of the couple having a daughter with hemophilia A is 0%.
A client's amniocentesis results were reported as 46, XY. Her obstetrician informed her at the time that everything "looks good." Shortly after birth the baby is diagnosed with cerebral palsy. Which of the following responses will explain this result? A. It is likely that the client received the wrong amniocentesis results B. Cerebral palsy is not a genetic disease C. The genes that caused cerebral palsy have not yet been discovered D. The genes were never tested for cerebral palsy
B Cerebral palsy is not a genetic disease. It is caused by a hypoxic injury that can occur at any time during pregnancy, labor and delivery, or the postdelivery period.
Which of the following is an attainable short-term goal for an 8-week gravid client who has a family history of cystic fibrosis? A. Have a sweat chloride test done B. Seek out genetic counseling C. Undergo chorionic villus sampling D. Be seen by a pulmonologist
B This goal is appropriate. Since the client has a family history of the disease, she should seek genetic counseling.
Which of the following client responses indicates that the nurse's teaching about care following chorionic villus sampling (CVS) has been successful? A. If the baby stops moving, the woman should immediately go to the hospital. B. The woman should take oral terbutaline every 2 hours for the next day. C. If the woman starts to bleed or to contract, she should call her physician. D. The woman should stay on complete bedrest for the next 48 hours.
C The mother should be notify the doctor if she begins to bleed or contrast.
The nurse is counseling a pregnant couple who are both carriers for phenylketonuria (PKU), an autosomal recessive disease. Which of the following comments by the nurse is appropriate? A. "I wish I could give you good news, but because this is your first pregnancy, your child will definitely have PKU." B. "Congratulations, you must feel relieved that the odds of having a sick child are so small." C. "There is a 2 out of 4 chance that your child will be a carrier like both of you." D. "There is a 2 out of 4 chance that your child will have PKU."
C This response is accurate.
At her first prenatal visit, a woman relates that her maternal aunt has cystic fibrosis (CF), an autosomal recessive illness. Which of the following comments is appropriate for the nurse to make at this time? A. "We can check to see whether or not you are a carrier for cystic fibrosis." B. "It is unnecessary for you to worry since your aunt is not a direct relation." C. "You should have an amniocentesis to see whether or not your child has the disease." D. "Please ask you mother whether she has ever had any symptoms of cystic fibrosis."
A It is possible that this woman is a carrier for cystic fibrosis (CF). A genetic evaluation can be done to determine that possibility.
A pregnant woman and her husband are both heterozygous for achondroplastic dwarfism, an autosomal dominant disease. The nurse advises the couple that their unborn child has which of the following probabilities of being of normal stature? A. 25% probability B. 50% probability C. 75% probability D. 100% probability
A The child has a 25% probability of being of normal stature.
Which statement by a gravid client who is a carrier for Duchenne muscular dystrophy, an X-linked recessive disease, indicates that she understands the implications of her status? A. "If I have a girl, she will be healthy." B. "None of my children will be at risk of the disease." C. "If I have a boy, he will be a carrier." D. "I am going to abort my fetus because it will be affected."
A This response is correct. As can be seen on the Punnett square, female children of carriers may carry the disease but do not express the disease.
A genetic counselor's report states, "The genetic nomenclature for this fetus is 46, XX." How should the nurse who reads this report interpret the cytogenetic results? A. The baby is female with a normal number of chromosomes B. The baby is hermaphroditic male with female chromosomes C. The baby is male with an undisclosed genetic anormaly D. There is insufficient information to answer this question
A This response is correct. The normal number of chromosomes is present - 46 - and the child is a female - XX.
A client is being interviewed prior to becoming pregnant. She states that she has a disease that is transmitted by mitochondrial inheritance. Which of the following statements is consistent with the client's disease? A. 100% of her children will be affected B. Only her female children will be affected C. Each fetus will have a 50% probability of being affected D. A fetus will be affected only if it inherits a similar gene from its father
A This statement is accurate. All of the woman's children will be affected.
A 25-year old woman, G0 P0000, enters the infertility clinic stating that she has just learned she is positive for the BRCA1 and the BRCA2 genes. She asks the nurse what her options are for getting pregnant and breastfeeding her baby. The nurse should base her reply on which of the following? A. Fertility of women who carry the BRCA1 and BRCA2 genes is similar to that of unaffected women. B. Women with these genes should be advised not to have children because the children could inherit the defective gene. C. Women with these genes should have their ovaries removed as soon as possible to prevent ovarian cancer. D. Lactation is contraindicated for women who carry the BRCA1 and BRCA2 genes.
A This statement is true. Female clients who are BRCA1 or BRCA2 positive have similar fertility rates to those who are BRCA1 and BRCA2 negative.
What is the rationale for testing all neonates for maple syrup urine disease (MSUD) when only 1 in 100,000 to 300,000 children will be born with the disease? A. To encourage the parents to have genetic testing done B. To prevent neurological disease in affected children C. To reduce the amount of money insurance companies must pay for sick MSUD children D. To persuage pharmaceutical companies to develop medications to treat children with MSUD
B This is the rationale for newborn testing for maple syrup urine disease. It is done to prevent neurological disease in affected children.
A woman who has had multiple miscarriages is advised to go through genetic testing. The client asks the nurse to rationale for this recommendation. The nurse should base his or her response on which of the following? A. The woman's pedigree may exhibit a mitochondrial inheritance pattern B. The majority of miscarriages are caused by genetic defects C. A woman's chromosomal pattern determines her fertility D. There is a genetic marker that detects the presence of an incompetent cervix
B This is true. The incidence of miscarriage is very high - about one out of every five pregnancies - and the majority of miscarriages are related to a genetic defect.
A client, G4 P4004, states that her husband has just been diagnosed with polycystic kidney disease (PKD), an autosomal dominant diease. The husband is heterozygous for PKD, while the client has no PKD genes. The client states, "I have not had out children tested because they have such a slim chance of inheriting the disease. We intend to wait until they are teenagers to do the testing." The nurse should base the reply on which of the following? A. Because affected individuals rarely exhibit symptoms before age 60, the children should be allowed to wait until they are adults to be tested. B. The woman may be exhibiting signs of denial since each of the couple's children has a 50/50 chance of developing the disease. C. Because the majority of the renal cysts that develop in affected individuals are harmless, it is completely unnecessary to have the children tested. D. The woman's husband should be seen by a genetic specialist since he is the person who is carrying the affected gene.
B This response is correct. As can be seen by the Punnett square results, the children have a 50/50 chance of developing PKD. Since the capital A connotes the dominant gene, the child needs only one affected gene to exhibit the disease.
The nurse discusses the results of a three generation pedigree with the proband who has breast cancer. Which of the following information must the nurse consider? A. The proband should have a complete genetic analysis done B. The proband is the first member of the family to be diagnosed C. The proband's first degree relatives should be included in the discussion D. The proband's sisters will likely develop breast cancer during their lives
B This statement is true. The proband is the first individual in any family to be identified with a disorder.
A woman asks a nurse about presymptomatic genetic testing for Huntington disease. The nurse should base her response on which of the following? A. There is no genetic marker for Huntington disease B. Presymptomatic resting cannot predict whether or not the gene will be expressed. C. If the woman is positive for the gene for Huntington, she will develop the disease later in like D. If the woman is negative for the gene, her children should be tested to see whether or not they are carriers.
C This answer is correct, if a person has the gene and lives long enough, virtually 100% of the time the disease will develop and progress.
A woman is seeking genetic counseling during her pregnancy. She has a strong family history of diabetes mellitus. She wishes to have an amniocentesis to determine whether she is carrying a baby who will "develop diabetes." Which of the following replies would be most appropriate for the nurse to make? A. "Doctors don't do amniocenteses to detect diabetes." B. "Diabetes cannot be diagnosed by looking at the genes." C. "Although diabetes does have a genetic component, diet and exercise also determine whether or not someone is diabetic." D. "Even if the baby doesn't carry the genes for diabetes, the baby could still develop the disease."
C This response is accurate. Diabetes is one of the many diseases that has both a genetic and an environmental component.
A woman who is a carrier for sickle cell anemia is advised that if her baby has two recessive genes, the penetrance of the disease is 100%, but the expressivity is variable. Which of the following explanations will clarify this communication for the mother? All babies with two recessive sickle cell genes will: A. Develop painful vaso-occlusive crises during their first year of life B. Exhibit at least some signs of the disease while in the neonatal nursery C. Show some symptoms of the disease but the severity of the symptoms will be individual D. Be diagnosed with sickle cell trait but will be healthy and disease-free throughout their lives
C This response is correct. Babies with two recessive sickle cell genes will show some symptoms of the disease but the severity of the symptoms will be individual.
A pregnant client asks the nurse, "I heard you can determine the health of my baby by taking some blood from me. Is that true?" Which of the following responses by the nurse is appropriate? A. "A new blood test has been developed that replaces the need for an amniocentesis." B. "A urine test is available that can screen your baby for a chromosomal defect, but it is not very reliable." C. "The only tests that can positively determine whether a baby has a chromosomal defect require analysis of your baby's skin cells." D. "There is a blood test available to screen for chromosomal defects, but it is not performed until the end of the second trimester."
C This statement is true. The only tests that can positively determine whether a baby has a chromosomal defect require analysis of the baby's skin cells.
A client, who is planning to become pregnant, tells the nurse, "I am so scared. My brother, who was born 2 years after I was, died a month after he was born. My mother says that he had a very serious genetic defect. I don't know what to do." Which of the following responses are appropriate for the nurse to make? (Select all that apply) A. "It is almost impossible to figure out what happened way back then, but I'm sure everything will be find with your baby." B. "Do you think your mother would allow your brother'd body to be unearthed so that it could be tested for the genetic disease?" C. "There are a number of tests that can be performed during your pregnancy to screen the baby for genetic diseases." D. "I will discuss your concerns with your obstetrician. I am sure your doctor will refer you to a genetic counselor who hopefully will be able to help you." E. "I think your mother should make an appointment to meet with your obstetrician. I'm sure she knows a lot more about your brother's illness than she is telling you."
C,D -There are a number of tests that can be performed during a pregnancy to screen the baby for genetic diseases: cell-free DNA analysis, first trimester screen, second trimester quad screens, CVS, and amniocentesis. -This is an appropriate response. This client should be referred for genetic counseling.
A woman is pregnant. During amniocentesis it is discovered that her child has Down syndrome with a mosaic chromosomal configuration. She asks the nurse what that means. What is the nurse's best response? A. "Instead of two number 21 chromosomes, your child has three." B. "Your baby's number 21 chromosomes have black and white bands on them." C. "Some of your baby's number 21 chromosomes are longer than others." D. "Some of your baby's cells have two number 21 chromosomes and some have three."
D Mosaicism is characterized by the fact that some of the cells of the body have the abnormal number of chromosomes but some of the cells have the normal number. This may happen with rapid disjunction. In Down syndrome, it means that some of the cells have three number 21 chromosomes and some have the normal number of two number 21 chromosomes. Mosaicism is not specific to Down syndrome but can occur with other chromosomal abnormalities.
A client wants to undergo amniocentesis because she has a family history of breast cancer. Which of the following choices is the most important information for the nurse to discuss with the client regarding the request? A. The breast cancer gene is highly penetrant B. The breast cancer gene has moderate expressivity C. The amniocentesis could result in a miscarriage D. The majority of breast cancers are not inherited
D The most important information for the nurse to provide the client is that the vast majority of cases of breast cancer are not inherited.
A woman is informed that she is a carrier for Tay-Sachs disease, an autosomal recessive illness. What is her phenotype? A. She has one recessive gene and one normal gene B. She has two recessive genes C. She exhibits all symptoms of the disease D. She exhibits no symptoms of the disease
D This is the woman's phenotype.
The genetic counselor informs a couple that they have a 25% chance probability of getting pregnant with a child with a severe genetic disease. The couple asks the nurse exactly what that means. Which of the following responses by the nurse is appropriate? A. Their first child will have the genetic disease B. If they have four children, one of the children will have the disease C. Their fourth child will have the genetic disease D. Any baby they conceive may have the disease
D This is true. Every time the woman gets pregnant, there is a possibility (25% chance) that she is carrying a child with the disease.
A male client has green color blindness, an X-linked recessive genetic disorder. His wife has no affected genes. Which of the following statements by the nurse is true regarding the couple's potential for having a child who is color blind? A. All male children will be color blind. B. All female children will be color blind C. All male children will be carriers for color blindness D. All female children will be carriers for color blindness
D This response is correct. All of the females will be carriers.
A couple inquire about the inheritance of Huntington disease (HD) because the prospective father's mother is dying of the illness. There is no history of the disease in his partner's family. The man has never been tested for HD. Which of the following responses by the nurse is appropriate? A. "Because HD is an autosomal dominant disease, each and every one of your children will have a 1 in 4 chance of having the disease." B. "Because only one of you has a family history of HD, the probability of any of your children having the disease is less than 10%. C. "Because HD is such a devastating disease, if there is any chance of passing the gen along, it would be advisable for you to adopt." D. "Because neither of you has been tested for HD, the most information I can give you is that each and every one of your children may have the disease."
D This statement is correct. No specific information can be given until or unless the potential father decides to be tested.
A woman asks the nurse, "My nuchal fold scan results were abnormal. What does that mean?" Which of the following comments is appropriate for the nurse to make at this time? A. "I am sorry to tell you that your baby will be born with a serious deformity." B. "The results show that you child will have cri du chat syndrome." C. "The test is done to see if you are high risk for preterm labor." D. "An abnormal test indicates that your baby may have a chromosomal disorder."
D This statement is true, but the definitive diagnosis can be made only via genetic testing.
A woman whose blood type is O- (negative) states, "My husband is AB+ (positive)." The mother requires the nurse about what blood type the baby will have. Which of the following blood types should the nurse advise the mother that the baby may have? (Select all that apply) A. Your baby could be type O+ B. Your baby could be type O- C. Your baby could be type AB- D. Your baby could be type A+ E. Your baby could be type B-
D,E -The baby could be blood type AO (type A) and, if the father is heterozygous for the Rh factor, the baby could be either Rh+ or Rh-. -The baby could be type BO (type B) and, if the father is heterozygous for the Rh factor, the baby could be either Rh+ or Rh-.