ch 5 patho

Marfan syndrome is a single-gene disorder that affects which type of tissue? Respiratory Muscular Connective Cutaneous

Connective Marfan syndrome is an autosomal dominant disorder of the connective tissue, which gives shape and structure to other tissues in the body and holds them in place. It affects several organ systems, including the eyes, cardiovascular system and the skeletal system.

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 what?

Contact the physician The nurse should contact the physician and request a different antibiotic as tetracycline is a known teratogenic agent.

Which disease is caused by a genetic defect of chloride transport? Cystic fibrosis Spherocytosis Phenylketonuria von Willebrand disease

Cystic fibrosis Cystic fibrosis is a single-gene inheritance disorder of membrane transport of chloride ions in exocrine glands, causing lung and pancreatic disease. The other options are also single-gene inheritance disorders but do not involve chloride transport.

The nurse is assessing a prepubertal male with fragile X syndrome. Assessment findings would include: Cleft palate Small face and hands Small inverted ears Large testes

Large testes The most distinctive feature that is present in 90% of prepubertal males with fragile X syndrome is macroorchidism or large testes. Someone with fragile X syndrome typically has a long face with large mandible and large, everted ears. Cleft palate is not associated with fragile X syndrome.

Which characteristic of genetic disorders involves a single-gene trait? Chromosome rearrangements Multifactorial gene mutations Abnormal numbers of chromosomes Mendelian patterns of inheritance

Mendelian patterns of inheritance Single-gene disorders are characterized by patterns of transmission that follow the Mendelian patterns of inheritance. Multifactorial inheritance involves more than one gene mutation, rearrangement of groups of genes, and uneven numbers of some chromosomes in each cell.

The tissue that is damaged in Huntington chorea is which of the following? Skin tissue Nerve tissue Muscle tissue Connective tissue

Nerve tissue Huntington chorea is a neurodegenerative disorder. It does not involve the other types of tissue.

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 Blindness Congenital heart defects Attention deficit disorder

Neural tube defects Folic acid deficiency has been implicated in the development of neural tube defects (anencephaly, spina bifida, encephalocele). Studies have shown a significant decrease in neural tube defects when folic acid was taken long term by women of reproductive age.

When quizzing obstetrical nursing students regarding tissues affected by mitochondrial DNA mutations, the instructor would accept which response? Select all that apply. Deafness Absent testes Retinal degeneration Cardiac valve abnormalities Palatal abnormalities

Retinal degeneration Deafness Mitochondrial DNA mutations generally affect tissues and organs that are highly dependent on oxidative phosphorylation to meet their high needs for metabolic energy. Thus, mitochondrial diseases frequently affect the brain and neuromuscular system and produce encephalomyopathies, retinal degeneration, loss of extraocular muscle function, lactic acidosis, and deafness.

Which condition follows a Mendelian pattern of recessive inheritance? Tay-Sachs disease Down syndrome Marfan syndrome Coronary artery disease

Tay-Sachs disease Tay-Sachs disease is an autosomal recessive disorder of Mendelian or single-gene inheritance. Coronary artery disease is a multifactorial inheritance disorder. Down syndrome is a numeric disorder involving autosomes. Marfan syndrome follows Mendelian inheritance but is autosomal dominant.

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? "This means you need to decrease your protein intake to prevent renal problems in your baby." "This means your baby has Down syndrome. We won't know how severe until after you give birth." "Elevated AFP means your baby is at risk of having a neural tube defect like spina bifida (an opening in the spine)." "This is normal. The problem is if it is low, that means your baby will be born with trisomy 18 and will be intellectually disabled."

"Elevated AFP means your baby is at risk of having a neural tube defect like spina bifida (an opening in the spine)." Maternal and amniotic fluid levels of AFP are elevated in pregnancies where the fetus has a neural tube defect (i.e., anencephaly and open spina bifida) or certain other malformations such as an anterior abdominal wall defect in which the fetal integument is not intact. Screening of maternal blood samples usually is done between weeks 16 and 18 of gestation. Although neural tube defects have been associated with elevated levels of AFP, decreased levels have been associated with Down syndrome.

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." "Androgen therapy can be initiated if there is evidence of a testosterone deficit." "He will grow to an above-average height." "We will need to send him to speech therapy."

"My child will have normal fertility when he matures." Males with an extra X chromosome have Klinefelter syndrome. Klinefelter syndrome is characterized by a tall stature, and most males have some degree of language impairment. Infertility is common in men with Klinefelter syndrome because of a decreased sperm count. Androgen therapy can be initiated if there is evidence of a testosterone deficit.

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? "The age of onset of most autosomal recessive disorders like PKU is later in life so it will be years before you know the child's status." "There will definitely be an abnormal protein structure that will result in muscle flaccidity when the infant tries to walk." "There is a 25% risk that the child will be a carrier of this trait but not afflicted with disease." "There is a 25% chance the child will be affected with the disease trait."

"There is a 25% chance the child will be affected with the disease trait." Autosomal recessive disorders include almost all inborn errors of metabolism, with deficiencies of enzymes rather than abnormal protein structure. Age of onset tends to be early in life. There is a two-in-four chance of having a child who is a carrier, but only a 25% risk for having an affected child. Phenylketonuria (PKU) is a rare autosomal recessive metabolic disorder that affects approximately 1 in every 10,000 to 15,000 infants in the United States. Infants with the disorder are treated with a special diet that restricts phenylalanine intake. If untreated, the disorder results in intellectual disability, microcephaly, delayed speech, and other signs of impaired neurologic development. Tay-Sachs disease is inherited as an autosomal recessive. Infants with Tay-Sachs disease appear normal at birth but begin to manifest progressive weakness, muscle flaccidity, and decreased responsiveness at approximately 6 to 10 months of age. The occurrence risks in each pregnancy (with both parents being carriers) are one in four (25%) for an affected child and two in four (50%) for a carrier child.

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. 75% of the population have syndactyly. 75% of the population with the gene for syndactyly will not have webbed toes or fingers. 75% of the population carry the gene for syndactyly.

75% of the people with the gene for syndactyly will have webbed toes or fingers. When a gene has a 75% penetrance, it means that 75% of the people with a particular genotype present with a recognizable phenotype. In this instance, 75% of the people with the gene for syndactyly will have webbed toes or fingers.

Which statement is true about recessive gene inheritance? Dominant genes have less power of expression than recessive ones. A carrier is a nonaffected person with a single copy of a recessive gene. Variability of gene expression is called reduced penetrance. X-linked recessive genes are expressed only if two X chromosomes are present.

A carrier is a nonaffected person with a single copy of a recessive gene. Autosomal recessive disorders are manifested only when both members of the gene pair are affected. Therefore, a carrier is a nonaffected person with a single copy of a recessive gene. Dominant genes have greater expression than recessive ones. Because of the presence of a normal X gene, female heterozygotes rarely experience the effects of a defective gene, whereas all males who receive the gene are typically affected. Variability of gene expression is called variable expressivity.

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 thin, middle-aged nonsmoking man with a repaired atrial septal defect. An overweight, middle-aged male smoker with coronary artery disease. A short, thin, 56-year-old woman with hypertension. A tall, thin, myopic, 28-year-old woman with mitral valve prolapse.

A tall, thin, myopic, 28-year-old woman with mitral valve prolapse. This client exhibits several classic signs of Marfan syndrome, an autosomal dominant genetic disorder of connective tissue. The other clients show signs of heart disease most likely caused by multiple factors.

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? Chorionic villus sampling Percutaneous umbilical cord blood sampling Biochemical analysis Amniocentesis

Amniocentesis 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.

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: Mongolian spots Lisch spots Plaques Cafe au lait spots

Cafe au lait spots The nurse should document the light brown, flat, cutaneous spots as being cafe au lait spots.

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 cocaine use Active herpes simplex infection Folic acid deficiency Chronic alcohol use

Chronic alcohol use The infant's signs and symptoms are characteristic of fetal alcohol syndrome. Folic acid deficiency is associated with neural tube defects, such as anencephaly and spina bifida. Cocaine use is associated with some of the same signs and symptoms as alcohol use but does not produce the characteristic facial abnormalities of fetal alcohol syndrome. Herpes simplex infection, although it is associated with microcephaly, hydrocephalus, defects of the eye, and hearing problems, also does not produce characteristic facial abnormalities.

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 Turner syndrome Patau syndrome Marfan syndrome

Down syndrome The risk of having a child with Down syndrome increases with maternal age—it is 1 in 1250 at 25 years of age, 1 in 400 at 35 years, and 1 in 100 at 45 years of age. The reason for the correlation between maternal age and nondisjunction is unknown, but is thought to reflect some aspect of aging of the oocyte. Although males continue to produce sperm throughout their reproductive life, females are born with all the oocytes they ever will have. These oocytes may change as a result of the aging process. With increasing age, there is a greater chance of a woman having been exposed to damaging environmental agents such as drugs, chemicals, and radiation. There is no correlation with maternal age and the other syndromes.

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? Gynecomastia Testicular agenesis Epicanthal eye folds Tall stature

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 other responses are not seen in Down syndrome.

Which risk factor increases the chances of the development of a neural tube defect during embryonic development? Ascorbic acid deficiency Calcium deficiency Iron deficiency Folate deficiency

Folate deficiency Folate deficiency has been closely linked as a risk factor for the development of neural tube defects because folate is needed for the synthesis of amino acids and DNA. It is now recommended that women take folic acid prior to conception to prevent neural tube defects.

After studying genetic disorders, the pathophysiology student knows that which of the following is true? Diabetes mellitus is caused by a single-gene defect. Sickle cell anemia is caused by multiple gene defects. Few diseases caused by single-gene defects have been identified. Genotype determines phenotype.

Genotype determines phenotype. The genetic composition of a person is called a genotype, whereas the phenotype is the observable expression of a genotype. Diabetes mellitus is caused by a multifactorial inheritance disorder and sickle cell anemia by a single gene defect. Many diseases caused by a single-gene defect have been identified.

The provider is counseling a client who has just been diagnosed with adult polycystic kidney disease, an autosomal dominant disorder. Which statement regarding the transmission of genetic disease is accurate? The trait will be expressed only if the defective gene is carried on the X chromosome. The trait will be expressed only if both parents have the gene defect. One affected parent will cause all children to be affected. Healthy or unaffected children are not carriers of the defective gene.

Healthy or unaffected children are not carriers of the defective gene. Adult polycystic kidney disease is an autosomal dominant disorder. In this disorder, a single mutant allele from an affected parent is transmitted to an offspring regardless of sex. The affected parent has a 50 percent chance of transmitting the disorder to each offspring. The unaffected relative of the parent or unaffected siblings of the offspring do not transmit the disorder.

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 Cardiac valvular disorders Kidney failure Thyroid metabolism errors

Impaired brain development Infants and children with classic and mild PKU require dietary protein restrictions to prevent intellectual disability, microcephaly, and other signs of impaired neurologic development. Affected infants are normal at birth but within a few weeks begin to develop a rising phenylalanine level and signs of impaired brain development. Seizures, other neurologic abnormalities, decreased pigmentation of the hair and skin, and eczema often accompany the intellectual disability in untreated infants.

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? Thyroid metabolism errors Impaired brain development Kidney failure Cardiac valvular disorders

Impaired brain development Infants and children with classic and mild PKU require dietary protein restrictions to prevent intellectual disability, microcephaly, and other signs of impaired neurologic development. Affected infants are normal at birth but within a few weeks begin to develop a rising phenylalanine level and signs of impaired brain development. Seizures, other neurologic abnormalities, decreased pigmentation of the hair and skin, and eczema often accompany the intellectual disability in untreated infants.

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: Klinefelter syndrome Marfan syndrome Down syndrome Neurofibromatosis type 1

Neurofibromatosis type 1 In more than 90% of persons with neurofibromatosis type 1, cutaneous and subcutaneous neurofibromas develop in late childhood or adolescence. The cutaneous neurofibromas, which vary in number from a few to many hundreds, manifest as soft, pedunculated lesions that project from the skin. Marfan syndrome affects several organ systems, including the ocular system (eyes), the cardiovascular system (heart and blood vessels), and the skeletal system (bones and joints). Down syndrome is a congenital condition characterized by varying degrees of intellectual disability and multiple defects. Klinefelter syndrome is a condition that occurs in men who have an extra X chromosome in most of their cells. The syndrome can affect different stages of physical, language, and social development. The most common symptom is infertility.

A nurse caring for a client with a genetic disorder of mitochondrial DNA assesses for abnormalities in which body system? Lymphatic Gastrointestinal Genitourinary Neuromuscular

Neuromuscular Mitochondrial DNA disorders, although rare, affect the tissues of the neuromuscular system.

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 Mumps Measles Pertussis

Rubella This defect may be caused by the teratogen rubella and is often encountered in children with chromosomal abnormalities.

Which microorganism can cross the placenta and enter the fetal circulation causing the most frequent fetal anomalies? Common cold virus Influenza B Streptococcus Rubella

Rubella TORCH stands for toxoplasmosis, other, rubella (German measles), cytomegalovirus, and herpes. This acronym can be used to remember the agents most frequently implicated in fetal anomalies. Strep throat, common colds, and the flu can cause concern for the mother but rarely result in fetal anomalies.

What will likely be the outcome when a male child inherits an X-linked disorder from his heterozygous carrier mother? His daughters will have the disorder. His father has the disorder. Some of his sisters will be carriers. His sons will be carriers.

Some of his sisters will be carriers. A male who has a recessive X-linked disorder will have daughters who are carriers and sons who are unaffected. Male children of a carrier mother have a 50% risk of having the disorder and cannot be carriers. Female children of a carrier mother have a 50% risk of being carriers and are not affected by the disorder.

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? Marfan syndrome von Recklinghausen disease Neurofibromatosis type 2 Tay-Sachs disease

Tay-Sachs disease Tay-Sachs disease is the only one of these diseases that is an autosomal recessive disorder. All the others are autosomal dominant disorders.

When the mother of an adolescent with Turner syndrome asks the nurse why the physician is prescribing estrogen therapy, the nurse provides which explanation? To prevent development of diabetes To promote intellectual development To promote secondary sex characteristics To prevent short stature

To promote secondary sex characteristics. Estrogen therapy is initiated in adolescents to girls with Turner syndrome to promote the development of secondary sex characteristics.

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: Isochromosome formation Ring formation Inversion Translocation

Translocation Translocation occurs when there are simultaneous breaks in two chromosomes, from different pairs, with exchange of chromosome parts. Isochromosome formation occurs when the centromere, or central portion, of the chromosome separates horizontally instead of vertically. Ring formation results when deletion is followed by uniting of the chromatids to form a ring. Inversion requires two breaks on a single chromosome with inversion to the opposite side of the centromere or with the fragment inverting but remaining on the same arm.

The provider is doing genetic counseling with a client. He explains that which condition affects only females? Turner syndrome Klinefelter syndrome Fragile X syndrome Down syndrome

Turner syndrome Turner syndrome is caused by an absence of all or part of the X chromosome. Down syndrome is a trisomy 21. Klinefelter syndrome is a condition of testicular dysgenesis accompanied by the presence of one or more extra X chromosomes in excess of the normal XY complement. Achondroplasia is a single-gene inheritance disorder.

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? Achondroplasia Klinefelter syndrome Turner syndrome Down syndrome

Turner syndrome Turner syndrome is caused by an absence of all or part of the X chromosome. Down syndrome is a trisomy 21. Klinefelter syndrome is a condition of testicular dysgenesis accompanied by the presence of one or more extra X chromosomes in excess of the normal XY complement. Achondroplasia is a single-gene inheritance disorder.

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? Aneuploidy of genes in all cells Heterozygote dominant trait Deficiencies in enzyme synthesis Variable expressivity of a gene

Variable expressivity of a gene Autosomal dominant disorders are characterized by variable gene penetrance (degree to which the trait is displayed) and expression (differences in how the trait is displayed). Aneuploidy is not a single-gene disorder and does not follow the Mendelian pattern of inheritance. Deficiencies of enzyme synthesis are common in autosomal recessive disorders.X-linked inheritance can be dominant or recessive, but it is not autosomal.

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? Cystic fibrosis Von Recklinghausen disease Klinefelter syndrome Down syndrome

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 café au lait spots. A Wood lamp, which uses ultraviolet light, can be used to detect lighter spots. The other options are chromosomal disorders and do not exhibit these pigmentations.

The nurse is explaining congenital defects to a newly pregnant client. She explains that one of the most common birth defects is: pyloric stenosis. spina bifida. congenital heart disease. cleft lip with or without cleft palate.

cleft lip with or without cleft palate. Cleft lip with or without cleft palate is one of the most common birth defects. Other congenital defects that are thought to arise through multifactorial inheritance are clubfoot, congenital dislocation of the hip, congenital heart disease, pyloric stenosis, and urinary tract malformation.

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? respiratory therapist occupational therapist lactation consultant social worker

lactation consultant Newborns with a cleft lip typically have difficulty with feeding, and the assistance of a lactation consultant may be of help in establishing feeding patterns. Oxygenation is not a typical problem, while activities of daily living and assistive devices are not relevant considerations. Although social work is often of assistance when a child is born with a congenital condition, a cleft lip has fewer implications than most other inherited disorders.

The nurse is studying genetic disorders. She learns that an allele is: the male or female half of a gene pair. the physical trait associated with a particular gene. the presence of more than two chromosomes to a set. one of two members of a gene pair, for a particular trait, in a chromosome pair.

one of two members of a gene pair, for a particular trait, in a chromosome pair. The two members of a gene pair, one inherited from the mother and the other from the father, are called alleles. The presence of more than two chromosomes to a set is called polysomy. The physical trait associated with a particular gene is the phenotype.

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. outside environmental substances, inside environmental substances, internal environmental substances. period of organogenesis, third trimester, 2nd trimester. drugs and chemical substances; smoking; bacteria and virus.

radiation; drugs and chemical substances; and infectious agents. Teratogenic agents have been divided into three groups: radiation; drugs and chemical substances; and infectious agents. The period of organogenesis, the third trimester, and the second trimester are not teratogenic substances. They are time periods during the pregnancy. Teratogenic substances are not classified as outside, inside, or internal. Although drugs and chemical substances are a class of teratogenic agents, smoking is included in that class as a teratogenic agent. It is not a class unto itself. Bacteria and viruses are considered infectious agents and are therefore teratogenic agents.