Chp. 5 Genetic and congenital Disorders

The nurse is studying genetic disorders. She learns that an allele is:

one of two members of a gene pair, for a particular trait, in a chromosome pair.

The nurse is teaching a class of pregnant woman about nutrition, emphasizing their need for folic acid. The nurse's rationale for this relates to prevention of which birth defect?

Neural tube defects

A pregnant client's α-fetoprotein (AFP) returns elevated. The couple ask the health care worker to explain what this means. Which is the best response?

"Elevated AFP means your baby is at risk of having a neural tube defect like spina bifida (an opening in the spine)."

The nurse is providing education to the parent of a male diagnosed with Marfan syndrome. The nurse knows that her teaching has been effective when the parent states which of the following?

"His participation in sports may need to be limited."

The nurse is evaluating teaching provided to a parent of a male newborn with a karyotype of 47, XXY. Which statement indicates more teaching is needed?

"My child will have normal fertility when he matures."

The physician suspects a client may have Klinefelter syndrome. To confirm the diagnosis, the chromosome pattern would identify:

47, XXY

A mother who has one mutant allele on the X chromosome and one normal allele asks the nurse what the percentage is of passing it on to a daughter to be a carrier. The best response would be:

50%

A newborn has been diagnosed with phenylketonuria (PKU). The nurse teaches the mother about a special diet to restrict phenylalanine intake. When does this diet need to be initiated?

7 to 10 days of age

Which statement is true about recessive gene inheritance?

A carrier is a nonaffected person with a single copy of a recessive gene.

A woman who is considering becoming pregnant has just been exposed to an environmental toxin. The woman contacts her doctor to ask if she is now at any risk. Which response would be considered most accurate?

A miscarriage of the fetus Environmental influences during the first 2 weeks after fertilization may interfere with implantation and result in abortion or early resorption of the products of conception. Exposure during the pregnancy can result in a variety of congenital disorders. Sterilization is possible but is dependent on a variety of factors.

A clinician who works on a cardiac care unit of a hospital is providing care for a number of clients. Which client most likely has a genetic disorder arising from inheritance of a single gene?

A tall, thin, myopic, 28-year-old woman with mitral valve prolapse.

Which pregnant woman likely has the greatest risk that her child will have a fetal anomaly?

A woman who has herpes simplex and who has recently recovered from endocarditis

A sonogram on a woman in the first trimester of her pregnancy shows abnormal fetal findings. The nurse prepares to provide the woman with information concerning which diagnostic procedure?

Amniocentesis

The nurse is caring for a client who tried to become pregnant but suffered a spontaneous abortion (miscarriage) during her first trimester. What is the most likely etiology of the client's abortion?

The fetus had a chromosomal disorder.

Which medications are teratogenic agents? Select all that apply.

Accutane Tetracycline Methotrexate

The gene responsible for a particular congenital cardiac anomaly is said to have complete penetrance. What are the clinical implications of this fact?

All the individuals who possess the gene will exhibit the anomaly.

Which term is used to describe the process when a child receives two members of a gene pair, one inherited from the mother and the other from the father?

Alleles

The criteria for fetal alcohol syndrome diagnosis require the documented presence of all of the following except which one?

An absence of all or part of the X chromosome

The nurse is studying numeric disorders involving autosomes. Which term refers to having an abnormal number of chromosomes?

Aneuploidy

A nurse notes that a client with neurofibromatosis has eight flat, cutaneous, light brown spots (2 cm in diameter each) over the trunk area. The nurse documents these as being:

Cafe au lait spots

The provider caring for a 38-year-old pregnant client wants to determine if the child will have Down syndrome. Which prenatal test is used to diagnose this condition?

Chromosome analysis

A woman gave birth to a small infant with a malformed skull. The infant grows slowly and shows signs of substantial cognitive and intellectual deficits. The child also has facial abnormalities that become more striking as it develops. What might the nurse expect to find in the mother's pregnancy history?

Chronic alcohol use

The U.S. Food and Drug Administration established a system in 1979 for classifying drugs according to their proven teratogenicity. Place these classes of drugs in order from least to greatest potential for teratogenicity.

Class A B C D X

A nurse is performing a head-to-toe assessment of a newborn with Down syndrome. Which assessment finding should the nurse bring to the attention of the health care provider?

Cleft lip

The nurse is preparing to administer a pregnant client's medication when it is noted that the client is prescribed tetracycline for an infection. The nurse should do which of the following?

Contact the physician

The nurse is providing prenatal education to a group of couples. In order to reduce anxiety, she provides information on multifactorial inheritance disorders. Which condition would be in this category?

Coronary artery disease

Which disease is caused by a genetic defect of chloride transport?

Cystic fibrosis

Decreased levels of maternal serum alpha-fetoprotein (AFP) have been associated with which disorder?

Down syndrome

With increasing age comes a greater chance of a woman having been exposed to damaging environmental agents such as drugs, chemicals, and radiation. These factors may act on the aging oocyte to cause which abnormality in a fetus?

Down syndrome

Which statement is true with regard to autosomal recessive disorders?

Effects are typically the result of alterations in enzyme function.

What statement is true concerning embryonic development?

Embryonic development is easily disturbed during the period of vulnerability (from day 15 to day 60 after conception).

Which action is an appropriate intervention by a nurse working with the parents of an infant newly diagnosed with Tay-Sachs disease?

Encourage parents to verbalize fears and feelings.

A nurse is assessing two children with the same genetic disorder where one child is severely impacted and the other is not. Which genetic characteristic is this an example of?

Expressivity

The parents of a 5-year-old boy are having their son evaluated for mental and physical abnormalities. He is showing signs of intellectual disability, and they fear he may have fragile X syndrome. To either confirm or deny the presence of fragile X, the laboratory should test for which gene?

FMR1

Is it true or false that prenatal screening can be used to rule out all possible fetal abnormalities?

False

The nurse teaches a woman planning on getting pregnant that it is most important to stay away from potential teratogens during which period in embryonic development?

From week 3 to week 9

After studying genetic disorders, the pathophysiology student knows that which of the following is true?

Genotype determines phenotype.

The nurse assessing a client with Klinefelter syndrome would evaluate which signs as being expected findings? Select all that apply.

Gynecomastia Testicular atrophy

A nurse caring for a child with type 1 neurofibromatosis notes that the child has pigmented nodules of the iris. Which of the following is the nurse reporting?

Lisch nodules

Mendelian inheritance characteristics are most closely associated with which one of the following?

Marfan syndrome

Which disorder is a single-gene mutation?

Marfan syndrome

Which characteristic of genetic disorders involves a single-gene trait?

Mendelian patterns of inheritance

The nurse teaches the pregnant radiation technologist that excessive levels of radiation have been shown to cause which conditions? Select all that apply.

Microcephaly Skeletal malformations Intellectual disability

A couple is scheduled to obtain familial lineage studies. The nurse is providing education. To which aspect of the DNA analysis should the woman pay particular attention regarding inherited disorders?

Mitochondrial DNA

A 16-year-old male presents to the clinic complaining of headaches, trouble hearing the teacher in the front of the classroom, and ringing in the ears. He also revealed that every time he goes swimming underwater, he gets disorientated (which never happened when he was younger). Given these manifestations, the health care provider is going to start testing for:

Neurofibromas

An adolescent presents at the clinic with reports of pedunculated lesions projecting from the skin on the trunk area. The nurse knows that this is a sign of:

Neurofibromatosis type 1

A pregnant mother (16 weeks' gestation) forgot and emptied her cat's litter box without gloves. She is extremely anxious and wants to be tested right away. Which test would the nurse prepare her for that would give rapid cytogenic analysis?

Percutaneous umbilical cord blood sampling

A 41-year-old woman has made the recent decision to start a family and is eager to undergo testing to mitigate the possibility of having a child with Down syndrome. Which test is mostlikely to provide the data the woman seeks?

Prenatal blood tests

The parents of an infant boy ask the nurse why their son was born with a cleft lip and palate. The nurse responds that cleft lip and palate are defects that are caused by many factors. The defect may also be caused by teratogens. Which teratogens can cause cleft lip and palate?

Rubella

Which microorganism can cross the placenta and enter the fetal circulation causing the most frequent fetal anomalies?

Rubella

Select the screening procedure performed on newborns to decrease the risk of intellectual disability and compromised neurological development.

Serum phenylalanine test

Which symptoms support the diagnosis of the autosomal recessive disorder Tay-Sachs disease?

Severe mental deterioration originating in infancy

Ultrasonography is most likely to detect which fetal abnormality?

Skeletal abnormalities

What will likely be the outcome when a male child inherits an X-linked disorder from his heterozygous carrier mother?

Some of his sisters will be carriers.

The health care provider is assessing a 6-month-old infant. The parents state that the child appeared normal at birth and in the first few months; however, they have seen the following changes in their infant: progressive weakness, muscle flaccidity, and decreased attentiveness. The health care provider suspects:

Tay-Sachs Disease

The health care provider informs the client that she is at risk for developing an autosomal recessive disorder. For which disorder may the client be at risk?

Tay-Sachs disease

Which condition follows a Mendelian pattern of recessive inheritance?

Tay-Sachs disease

A pregnant client is just completing her first trimester and has opted for alpha-fetoprotein (AFP) and human chorionic gonadotropin (hCG) testing. The nurse should identify what implication from this client's decision?

The client wishes to know about her fetus' risk of having a trisomy.

Select the statement that best describes a female with Turner syndrome.

The female will have normal body proportions.

When parents give birth to a child with a defect, they focus on getting answers to which two priority issues?

The immediate and future care of the affected child, and the possibility of future children in the family having a similar defect

The embryo is most susceptible to adverse influences during the period from 15 to 60 days after conception. Which term is used to describe this period?

The period of organogenesis

Although multifactorial traits cannot be predicted with the same degree of accuracy as Mendelian single-gene mutations, which characteristic patterns exist in this disorder? Select all that apply.

The risk increases with increasing incidence of the defect among relatives. Involvement of a single organ or tissue derived from the same embryonic developmental field The risk of recurrence in future pregnancies is for the same or a similar defect.

The genetic counselor is explaining structural changes in chromosomes that result from breakage and rearrangement of chromosome parts. The pattern that occurs when there are simultaneous breaks in two chromosomes, from different pairs, with exchange of chromosome parts is:

Translocation

The provider is doing genetic counseling with a client. He explains that which condition affects only females?

Turner Syndrome

The provider receives fetal karyotype results on one of his clients. The karyotype describes an absence of all or part of the X chromosome. Which condition does the fetus exhibit?

Turner syndrome

The nurse is assessing a newborn. What characteristic finding makes the nurse suspect the newborn has trisomy 21?

Upward slanting of eyes/Epicanthal eye folds

Polydactyly may be expressed in either the fingers or toes. This is an example of which of the following?

Variable expressivity

In one family, a son was born with polydactyly toes while his sister had polydactyly fingers. In explaining this phenomenon in genetic terms to the parents, which concept should be addressed?

Variable expressivity of a gene

While examining a client, the practitioner notices large, flat, cutaneous pigmentations. They are a uniform light brown with sharply demarcated edges. He uses a Wood lamp to better detect the lighter spots. The practitioner knows that the pigmentations may be a component of which disorder?

Von Recklinghausen disease

When can a teratogenic environmental agent cause birth defects?

When exposure occurs during early pregnancy

A client goes to radiology for a series of x-rays. As the lead apron is placed over the client, he asks why it is needed. The client should be told that the vest is to protect:

against chromosomal breakage.

Unlike other teratogens, alcohol exposure during pregnancy (fetal alcohol spectrum disorders) can have what harmful effect on the fetus?

developmental abnormalities throughout the prenatal and postnatal period

A young man has been diagnosed with Huntington disease following several months of progressive muscle weakness. The man has two young children: one boy and one girl. The nurse should teach the man that:

each child has 50% chance of developing Huntington disease.

The most critical time for teratogenic influence in embryonic development is:

from day 15 to day 60 after conception.

The nurse explains to prospective parents that AA or aa in a Punnett square represent two alleles of a given pair that are the same, or:

homozygotes.

Which health care provider is the highest priority for immediate assistance in the first 24 hours following the birth of a newborn with a cleft lip?

lactation consultant

Performing chorionic villi sampling prior to 10 weeks' gestation is not recommended because of the danger of:

limb reduction defects in the fetus.

A nurse is caring for an infant born with a cleft lip and palate. The priority of care would address:

malnutrition.

Teratogenic substances cause abnormalities during embryonic and fetal development. These substances have been divided into three classes. These classes are called:

radiation; drugs and chemical substances; and infectious agents.

The nurse teaches the client that ultrasonography will be used during prenatal testing to identify what type of abnormalities?

skeletal anomalies

Infections with the TORCH agents are reported to occur in 1% to 5% of newborn infants in the United States and are among the major causes of neonatal morbidity and mortality. Which of these are clinical and pathologic manifestations of TORCH?

Microcephaly, hydrocephalus, thrombocytopenia

A couple who are pregnant with their first child have made an appointment with a clinical geneticist to discuss prenatal screening. The man states that they "just want to make sure that there is nothing wrong with our baby." How could the clinician best respond to this statement?

"Testing the umbilical blood and performing amniocentesis can give us some information but not a guarantee."

Both members of a couple are carriers of an autosomal recessive trait. What will the nurse teach the couple about the risk of their child being affected?

"There is a 25% chance the child will be affected with the disease trait."

The mother of a child with Turner syndrome asks the nurse what the physician meant when the disease was explained as monosomy of the X chromosome. The nurse explains the syndrome as having which of the following characteristics?

"There is one X chromosome."

The parents of a newborn are relieved that their baby was born healthy, with the exception of a cleft lip that will be surgically corrected in 10 to 12 weeks. Which statement by the nurse to the parent's best conveys the probable cause of the newborn's cleft lip?

"Your newborn's cleft lip likely results from the interplay between environment and genes."

A nurse reading an epidemiological study sees that syndactyly is a genetic mutation with 75% penetrance. What does this mean for the client?

75% of the people with the gene for syndactyly will have webbed toes or fingers.

A newly pregnant female is worried about her baby. She recently returned from a mission trip to Africa. She was told there was a rubella outbreak in the next village. She has been given a TORCH screening test. If she has exposed her fetus to rubella, the nurse would expect the infant to display which possible birth defects?

Blindness

Marfan syndrome, which is a connective tissue disorder, affects several organ systems. The most life-threatening aspects of the disorder are caused by defects in which system?

Cardiovascular

A pregnant woman's ultrasound reveals intrauterine growth retardation (IUGR) and a TORCH agent is thought to be the cause. Which nursing action is appropriate?

Determine whether the client has been immunized against rubella.

A pregnant client has just undergone cytogenetic studies to determine fetal karyotyping. She learns that her fetus has trisomy 21. Which of the following is a manifestation of this condition?

Epicanthal eye folds

Following routine newborn testing, an infant has been diagnosed with an elevated phenylalanine level. The nurse teaches the parents to follow a strict low-protein diet to prevent which major complication for the infant?

Impaired brain development

While teaching a client, the nurse should emphasize which information about an autosomal dominant disorder?

It has variation in gene penetration and expression.

Which of the following is a cytogenetic disease?

Klinefelter syndrome

Which variables determine the extent of teratogenic drug effects? Select all that apply.

Molecular weight of the drug Stage of fetal development at time of exposure Duration of drug exposure

Sometimes an individual who developed from a single zygote is found to have two or more kinds of genetically different cell populations. These individuals are called:

Mosaic

The tissue that is damaged in Huntington chorea is which of the following?

Nerve tissue

After attending a preconception workshop, a young woman asks the educator to explain neural tube defects (NTD). Which conditions are examples of neural tube defects? Select all that apply.

Spina bifida Encephalocele Anencephaly

Genetic counseling and prenatal screening are tools both for the parents of a child with a defect and for those couples who want a child but are at high risk for having a child with a genetic problem. What are the objectives of prenatal screening?

To detect fetal abnormalities and to provide parents with information needed to make an informed choice about having a child with an abnormality

A child has been diagnosed with neurofibromatosis type 1 (NF-1). The nurse should assess the child for which clinical manifestations? Select all that apply.

Tonic-clonic seizures Early speech development Attention deficit disorder