Chapter 7 Porths Pathophysiology
The parents of a newborn infant are relieved that their baby was born healthy, with the exception of a cleft lip that will be surgically corrected in 10 or 12 weeks. Which of the nurse's following statements to the parents best conveys the probable cause of the infant's cleft lip?
"Your child's cleft lip likely results from the interplay between environment and genes."
A woman homozygous for the gene mutation that causes cystic fibrosis, with a partner who does not carry the same mutation, has what chance of having a child with the disease?
0% chance
To avoid congenital thyroid dysfunction, a pregnant woman must avoid any exposure to therapeutic radioactive iodine until what time in her pregnancy?
3rd trimester
A diagnosis of Klinefelter syndrome would be supported by proof of which chromosome pattern?
47, XXY
What is the risk that a mother with the genetic mutation that causes fragile X syndrome will pass the gene on to offspring?
50% of males will be affected
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?
7-10 days of age Dietary treatment of PKU must be started early in neonatal life to prevent brain damage. Infants with elevated phenylalanine levels should begin treatment by 7-10 days of age.
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 of the following systems?
cardiovascular
The tissue that is damaged in Huntington chorea is which of the following?
nerve tissue
The nurse is learning about mitochondrial DNA mutations. She learns that they generally affect which of the following tissues and organs?
neuromuscular
After attending a preconception workshop, a young woman asks the educator to explain neural tube defects (NTD). Which of the following are examples of neural tube defects?
• Spina bifida • Anencephaly • Encephalocele
What is the percentage risk that a mother with a mutant allele on the X chromosome will pass it on to her daughter?
50% The common pattern of inheritance is one in which an unaffected mother carries one normal and one mutant allele on the X chromosome. This means that she has a 50% chance of transmitting the defective gene to her sons, and her daughters have a 50% chance of being carrier of the mutant gene
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 diagnosticis procedure?
Amniocentesis The amniocentesis is useful in women with elevated risk on first trimester screen or quad screen; abnormal fetal findings on sonogram; or in parents who are carriers or with a strong family history of an inherited disease. Chorionic villus sampling is an invasive diagnostic procedure that obtains tissue that can be used for fetal chromosome studies, DNA analysis and biochemical studies. Percutaneous umbilical cord blood sampling (PUBS) is used for prenatal diagnosis of hemoglobinopathies, coagulation disorders, metabolic and cytogenetic disorders, and immunodeficiencies. Biochemical analyses can be used to detect abnormal levels of AFP and abnormal biochemical products in the maternal blood and in specimens of amniotic fluid and fetal blood.
Which foods should a pregnant woman consume to help achieve an adequate intake of folic acid?
Boxed dry cereal
The provider caring for a 38-year-old pregnant patient wants to determine if the child will have Down syndrome. Which prenatal test is used to diagnose this condition?
Chromosome analysis
The nurse is explaining congenital defects to a newly pregnant patient. She explains that one of the most common birth defects is which of the following?
Cleft lip with or without cleft palate
Maternal serum alpha-fetoprotein (AFP) is a screening test for which of the following conditions?
Downs syndrome
Which statement is true of autosomal recessive disorders?
Effects are typically the result of alterations in enzyme function. With autosomal recessive disorders, the age of onset is frequently early in life; the symptomatology tends to be more uniform than with autosomal dominant disorders; and the disorders are characteristically caused by loss-of-function mutations, many of which impair or eliminate the function of an enzyme. Mutations typically occur in nuclear, rather than mitochondrial, DNA
Which assessment finding assists the nurse in confirming that a prepubertal male may have fragile X syndrome?
Enlarged testes
A pregnant patient 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 A child with Down syndrome, or trisomy 21, has a flat facial profile, with a small nose and somewhat depressed nasal bridge; small folds in the inner corners of the eyes (epicanthal folds) and upward slanting of the eyes.
The most critical time for teratogenic influence in embryonic development is which one of the following?
From day 15 to day 60 after conception
Which assessment finding would help support the diagnosis of fetal alcohol syndrome (FAS) in a newborn?
Head circumference below the 10th percentile
The provider is counseling his patient who has just been diagnosed with adult polycystic kidney disease. Which of the following statements regarding the transmission of genetic disease is accurate?
Healthy or unaffected children are not carriers of the defective gene.
How is fetal alcohol syndrome (FAS) unlike other teratogens in regard to the harmful effects on the fetus?
It extends throughout the pregnancy Unlike other teratogenic exposures that cause abnormalities during a short period of time during fetal development (usually in the early weeks), fetal alcohol damages the chromosomes of the developing fetus as long as alcohol continues to circulate through the fetal bloodstream. FAS is diagnosed by the presence of three findings that do not include liver abnormalities, and are not life-threatening. Facial features characteristic of FAS are most noticeable during childhood.
What should the nurse teach the patient about an autosomal dominant disorder?
It has varied gene penetration and expression.
Which of the following is a cytogenetic disease?
Klinefelter syndrome
Mendelian inheritance characteristics are most closely associated with which one of the following?
Marfan syndrome
A woman who is a carrier for which disease possesses the greatest likelihood of passing the disease to her future children when heterozygous pairing exists?
Neurofibromatosis
The nurse is studying genetic disorders. She learns that an allele is which of the following?
One of two members of a gene pair, for a particular trait, in a chromosome pair
Which of the following health problems may be identified by a TORCH screening test?
Rubella and herpes The acronym TORCH stands for toxoplasmosis, other, rubella (i.e., German measles), cytomegalovirus, and herpes, which are the agents most frequently implicated in fetal anomalies. The TORCH screening test examines the infant's serum for the presence of antibodies to these agents.
The nurse teaches a pregnant woman about screening tests for her newborn. The nurse teaches that which test will assess for the risk of mental retardation and impaired neurological development?
Serum phenylalanine test
Which symptoms support the diagnosis of the autosomal recessive disorder Tay-sachs disease?
Severe mental deterioration originating in infancy
What assessment finding supports the diagnosis of Turner syndrome?
Short stature
Which of the following conditions follows a Mendelian pattern of recessive inheritance?
Tay-Sachs disease
Genetic testing has revealed that a male infant has been born with an extra X chromosome. What are the most likely implications of this finding?
The child is likely to have no manifestations of this chromosomal abnormality.
What will the nurse teach the patient about an Autosomal recessive disorder?
There are inborn errors of metabolism.
The provider receives fetal karotype results on one of his patients. The karotype describes an absence of all or part of the X chromosome. Which condition does the fetus exhibit?
Turner syndrome
While examining a patient, 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 A second major component of type 1 neurofibromatosis, or von Recklinghausen disease, is the presence of large, flat cutaneous pigmentations known as cafe' au lait spots. A Wood lamp, which uses ultraviolet light, can be used to detect lighter spots.
A pregnant woman should not take medications classified in what category?
X
Two members of a gene pair, one inherited from the mother and the other from the father, are known as which of the following?
an allele
Congenital disorders that are thought to arise through multifactorial inheritance include
cleft lip or palate, clubfoot, congenital dislocation of the hip, congenital heart disease, pyloric stenosis, and urinary tract malformations (hypospadias).
Performing chorionic villi sampling prior to 10 weeks gestation is not recommended because of the danger of which of the following?
limb reduction defects in the fetus
Ultrasonography is most likely to detect which of the following fetal abnormalities?
skeletal abnormalities
Polydactyly may be expressed in either the fingers or toes. This is an example of which of the following?
variable expressivity
Which of the following statements is true concerning percutaneous umbilical cord blood sampling (PUBS)? Select all that apply.
• A PUBS is an invasive procedure. • A PUBS requires ultrasonographic guidance. • A PUBS results are available in 48-72 hours. • A PUBS can assist in the diagnosis of fetal coagulation disorders.
Which of the following medications are teratogenic agents? Select all that apply.
• Accutane • Tetracycline • Methotrexate Vitamin A and its derivatives (the retinoids) have been targeted for concern because of their teratogenic potential. Concern over the teratogenic effects of vitamin A derivatives arose with the introduction of the acne drug isotretinoin (Accutane). Tetracycline can interfere with the mineralization phase of tooth development. Methotrexate is also a teratogenic medication. Aspirin and metoprolol are not teratogenic.
Which of the following procedures can be used to collect cells that can be used for fetal karyotyping? Select all that apply.
• Amniocentesis • Percutaneous umbilical cord blood sampling • Chorionic villus sampling
The nurse is teaching a preconception workshop for young adults. She knows that her students understand her teaching when they state which of the following are teratogenic agents? Select all that apply.
• Having a glass of wine with dinner • Casual use of cocaine • The use of warfarin for DVT
When preparing educational materials on autosomal dominant disorders, the nurse will include information on which of the following? Select all that apply.
• Huntington Chorea • von Willebrand disease • Marfan syndrome • Osteogenesis imperfecta
Children with von Recklinghausen disease are susceptible to neurologic complications. These include which of the following? Select all that apply.
• Increased incidence of learning disabilities • Complex partial and generalized tonic-clonic seizures • Optic gliomas • Attention deficit disorders
The nurse is preparing a presentation on disorders of organ systems associated with mitochondrial DNA (mtDNA) mutations. Which disorders will she include? Select all that apply.
• Leigh disease • Kearns-Sayre syndrome • Myoclonic epilepsy with ragged red fibers
The nurse teaches the pregnant radiation technologist that excessive levels of radiation have been shown to cause which of the following? Select all that apply.
• Microcephaly • Skeletal malformations • Mental retardation
Which of the following variables determine the extent of teratogenic drug effects? Select all that apply.
• Molecular weight of the drug • Stage of pregnancy when the drug was taken • Duration of drug exposure
