Chapter 10 Enzyme and Collagen Disorders

Chapter 10: Enzyme and Collagen Disorders ____ 1. Why does a newborn with a genetic enzyme deficiency have a normal phenotype at birth? B. The deficient enzyme’s activity was performed by maternal enzymes before birth. ____ 2. Which dietary alterations are necessary to help reduce the complications of phenylketonuria (PKU)? D. Decreased intake of phenylalanine; increased intake of tyrosine ____ 3. Which ethnic group has the highest incidence of a mutation in the PAH gene? C. Celts from Ireland and Scotland ____ 4. Which manifestation is a characteristic feature of untreated phenylketonuria (PKU)? D. Small stature ____ 5. Which action or behavior is considered an “executive function”? C. Deciding what to give as a present ____ 6. What is the expected outcome of pregnancy for women with phenylketonuria (PKU) when the blood ____ 7. Which statement regarding lysosomal storage diseases is true? C. Defective enzymes result in the accumulation of potentially toxic substances. ____ 8. If a man with Gaucher type 1 has children with a woman who is a carrier for the disorder, what is the ____ 9. Which ethnic group has the highest incidence of Gaucher disease? A. Ashkenazi Jews levels of phenylalanine are high throughout the pregnancy? D. There is a high incidence of cardiovascular birth defects. expected risk pattern? C. All children will have one mutated allele and will at least be carriers; each child of either gender has a 50% risk of having the disease. ____ 10. Why is it important to diagnose Gaucher type 1 disease as soon as possible after birth? A. Enzyme therapy can reduce complications for some patients. ____ 11. How does intravenous enzyme-replacement therapy for Gaucher disease reduce the organ storage of glucosylceramide? D. The enzyme is absorbed through the plasma membranes of affected cells and converts the stored glucosylceramide into its constituent molecules. ____ 12. Which assessment finding in a 6-month-old child suggests a possible lysosomal storage disease? A. Enlarged, palpable liver ____ 13. Which therapeutic option has been found beneficial for patients with Gaucher type 1 disease? D. Intravenous enzyme replacement with imiglucerase (Cerezyme) ____ 14. For which disorder is the drug idursulfase (Elaprase) appropriate for enzyme-replacement therapy? B. Hunter syndrome ____ 15. How are the two mucopolysaccharide disorders Hurler syndrome and Hunter syndrome different? C. Individuals with Hurler syndrome become cognitively impaired in early childhood, whereas those with Hunter syndrome often retain intellectual ability until later in life ____ 16. Why does a person with Hurler syndrome have an enlarged abdomen? B. The excess mucopolysaccharides accumulate inside the cells of the liver and the spleen. ____ 17. A pair of unrelated 4-year-olds (Lester and Lucy) have mucopolysaccharidosis 1 (MPS1). Lester has severe dysmorphic features and many skeletal anomalies. Lucy has only mildly coarse features and slight developmental delay. What is the best explanation for these differences? D. The disorder has wide variability in expression of severity. ____ 18. If a man with Fabry disease has children with a woman who is a carrier for the disorder, what is the expected risk pattern? B. Sons have a 50% risk for being affected; all daughters will either be affected or carriers. ____ 19. A woman who is a carrier for Fabry disease has children with a man who does not have the disorder. Their son has the disease, and their daughter also has some symptoms of Fabry disease even though she could only have inherited one affected allele. What is the explanation for the daughter having some symptoms of Fabry disease? C. The inactivation of one X chromosome in female cells is a totally random event. ____ 20. What is the pathologic basis of Fabry disease? B. Increased accumulation of globotriaosylceramide ____ 21. Which manifestation in a teenage boy whose mother is a carrier for Fabry disease suggests the boy may have the disorder? B. Opacity is present in both eyes. ____ 22. Couples from which ethnic group would derive the greatest benefit from genetic testing for Tay– Sachs disease? A. Ashkenazi Jews ____ 23. Which clinical manifestation in a 6-month-old infant is most diagnostic for Tay–Sachs disease? C. Cherry red spot on the retina ____ 24. Which substance fails to form normally in individuals with Marfan syndrome? D. Fibrillin ____ 25. Which health problem could be expected as a result of a gene mutation that affects the correct production and function of type 1 collagen? B. Increased incidence of arterial and venous aneurysms ____ 26. A son with osteogenesis imperfecta is born to parents with no family history of the disease. What is the most likely explanation for the son’s disorder? C. The gamete of one parent had a spontaneous mutation. ____ 27. Which manifestation is most common among individuals with osteogenesis imperfecta type I? D. Blue-tinged sclerae ____ 28. The mother of a teenager recently diagnosed with osteogenesis imperfecta type I (OI) asks if the problem is related to the fact that she adhered to a vegetarian diet during pregnancy. What is the most appropriate response? A. Your diet is not related to this disease because it is an inherited disorder. ____ 29. What is the most common cause of death among individuals with vascular Ehlers–Danlos (Ehlers– Danlos type IV)? C. Intestinal rupture ____ 30. A 12-year-old boy with Marfan syndrome complains to his nurse-practitioner, “My mother won’t let me play football or do anything else. Isn’t there something I can do besides sitting and playing video games?” Which of the following activities may be considered less risky for this child to perform? Select all that apply. B. Riding his bike with his friends C. Playing table tennis E. Archery F. Recreational ice-skating G. Hiking low- to moderate-difficulty trails