Alexandria University Student name: ______Medical Research Institute Semester: Fall Chemical Pathology Department Academic year: 2020– 2021 MD Degree Time allowed: 60 minutes Course title: Evaluation of inborn errors of Date: 02 / 12 / 2020 metabolism by laboratory means Total marks: 25 Course code: 1717807 Midterm exam All questions to be attempted
I. Choose the correct answer (only a SINGLE answer is CORRECT): (0.5 Mark for each question / 1 minute for each question)
1. The most common gene mutation in Cystic fibrosis is______. a. DF508 b. DF509 c. G551D d. Door man
2. Immunoreactive trypsinogen (IRT) dried blood spot level ______in cystic fibrosis. a. Is decreased b. Is increased c. Does not change d. Fluctuates
3. Sweat testing for______is the gold standard for Cystic fibrosis diagnosis. a. Conductivity b. Sodium c. Chloride d. Electrolytes content
4. Sweat conductivity is ______to sweat chloride measurement. a. Equal b. lower than c. Higher than d. not related
5. Which of the followings techniques could not be used in diagnosis of cystic fibrosis? a. Iso-electric focusing b. Ion selective electrode c. Conductivity d. Coulometry Page 1 out of 6
6. The main defect in cystic fibrosis is impairment of cystic fibrosis transmembrane conductance regulator protein (CFTR) function which affects______. a. Sodium channels b. Chloride cannels c. Calcium Channels d. ATP exchange transporter is sweat glands
7. Which of the following is NOT characteristic of unconjugated bilirubin? a. Lipophilic b. Indirectly reacting with Diazo reagent c. Exposed polar groups d. Internalized polar groups
8. Glutathione-S transferase enzyme inhibits______. a. Influx of bilirubin to hepatic cells b. Efflux of bilirubin out of hepatic cells c. Renal filtration and influx of bilirubin in glomeruli d. Bilirubin crossing the blood brain barrier
9. Gilbert disease is characterized by all of the following EXCEPT a. Unconjugated hyperbilirubinema b. Fasting hyperbilirubinemia c. Increased AA repeats in the promoter region of uridine diphosphate -glucuronosyl transferase enzyme (UGT1A1) gene d. Benign outcome
10. Phenobarbitone is used in treatment of Crigler Najjar type II for its ______. a. inhibitory effect on hepatic glucuronyl transferase b. inducing effect on hepatic glucuronyl transferase c. normalizing effect on alanine and aspartate aminotransferases (ALT and AST) activities d. ability to decrease gamma glutamyl transferase activity
11. Bilirubin binding with albumin: a. Increase bilirubin solubility in plasma b. Increase renal excretion of bilirubin c. Prevents tissue deposition d. Prevents bilirubin toxic effect on tissues
12. Unconjugated bilirubin is NOT characterized by being______. a. Albumin bound b. In need for an accelerator to react with Van den berg reagent c. Mainly present in low concentration d. Lypophilic
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13. Which of the followings is NOT a criterion of post hepatic jaundice? a. Dark coloured urine b. Pale colored stool c. Pruritis d. Kernicterus
14. Phototherapy causes all of the following changes EXCEPT ______. a. Increase water solubility b. Close the linear structure ring form of bilirubin c. Decrease bilirubin toxicity d. Enhance bilirubin excretion
15. Which of the following condition is characterized by dark urine? a. Gilbert disease b. Crigler Najjar disease c. Dubin Johnson d. Fatty liver
16. Which of the following statements is NOT CORRECT? a. Conductivity testing can help in the diagnosis of cystic fibrosis b. Absence of DNA mutations can categorically rule out cystic fibrosis c. Sweat sodium testing cannot be sued to diagnosed cystic fibrosis d. Sweat conductivity has a higher cutoff value that chloride testing
17. In newborn babies affected with cystic fibrosis, elevated immuno-reactive trypsinogen is due to ______. a. Autoimmune reaction against trypsinogen b. Decrease alpha and beta cell functions of the pancreas c. Partially blocked pancreatic duct d. Cross reactive serum amylase enzyme
18. Cystic fibrosis is______. a. An autosomal recessive disorder b. The most common monogenic trait in Caucasians c. Presentable only with respiratory manifestations d. Not treated with bone marrow transplantation
19. The commonest childhood presentation of familial hypercholesterolemia is______. a. acute pancreatitis b. cutaneous xanthomata c. statorrhea d. lipemia retinalis
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20. Dysbetalipopriteinemia is characterized by accumulation of lipoprotein remnants and cholesterol-enriched lipoprotein of a density______. a. Less than 1.006 g/ml b. More than 1.006 g/ml c. Less than 1.016 g/ml d. More than 1.016 g/ml
21. Palmar xanthomas are characteristic findings in______. a. Hyperlipoproteinemia type 1 b. Dysbetalipoproteinemia Type III c. Familial hypertriglyceridemia d. Type V Hyperlipoproteinemia
22. Hyperlipioproteinemia type I is characterized by mutations of ______gene. a. Lipoprotein lipase b. Acyl CoA dehydrogenase c. Low density lipoprotein adaptor protein d. Apo B48
23. The dietary fats are transported in the circulation as ______. a. Micelles b. Chylomicons c. Fatty acid – Albumin complex d. Liposomes
II. Choose true or false: (0.5 Mark for each question / 1 minute for each question)
24. Glycogen phosphorylase enzyme catalyzes the release of glucose-6-phosphate from the terminal residue of a non-reducing end of a glycogen branch, by means of phosphorolysis. (True – False)
25. Glycogen storage diseases primarily affecting muscles usually manifest with muscle cramps, fasting hypoglycemia, exercise intolerance, fatigue and weakness. (True – False)
26. Deficiency of debranching enzyme results in a glycogen molecule smaller than the original, with very short chains on the outer branches but with the inner core unchanged (a limit dextrin). (True – False)
27. Type Ia glycogen storage disease is caused by a defect in the glucose-6-phosphate transporter. (True – False)
28. Anemia of type I glycogen storage disease may be refractory to iron because of hepcidin deficiency. (True – False) Page 4 out of 6
29. Hyperuricemia in type I glycogen storage disease may be a secondary effect to excess lactate. (True – False)
30. Galactose-1-phosphate uridylyl transferase (GALT) enzyme deficiency is the most common enzymatic deficiency causing galactosemia. (True – False)
31. A positive breath hydrogen results following ingestion of lactose, sucrose or trehalose may also occur in glucose-galactose malabsorption. (True – False)
32. In the Beutler fluorescent spot test: When the blood spot fluoresces, the test is positive yet it can also be falsely positive in patients who are actively hemolysing. (True – False)
33. Intestinal lactase enzyme is essential in infancy, so a congenital lactase deficiency screening program must be available to all neonates at birth. (True – False)
34. The single most common absorptive defect in adults is lactose intolerance. (True – False)
35. Some individuals suffering from deficiency in uridine diphosphate galactose-4-epimerase enzyme (GALE) are healthy and require no treatment. (True – False)
36. Infants with galactosemia can become jaundiced. Hyperbilirubinemia is often unconjugated but can become conjugated later. (True – False)
37. In galactokinase enzyme deficiency, a lactose-free diet can reverse cataracts if started in early infancy with no long term complications. (True – False)
38. All monosaccharides and the common disaccharides – sucrose and lactose – are directly detected by Benedict's reagent. (True – False)
39. Life-threatening episodes of fasting hypoglycemia may result from hepatic hereditary fructose intolerance. (True – False)
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III. Match the CORRECT choice with each sentence (0.5 Mark for each question / 1.5 minutes for each question) 40 The failure of blood glucose to increase in A intestinal biopsy. response to galactose or fructose administration (oral then intravenous) is diagnostic of
41 Trehalase activities can only be measured in B liver biopsy
42 Glucose 6-phosphatase activity can be assayed in C polycystic ovaries
43 -is one of the Long term complication of Type I D premature ovarian failure Glycogen Storage Disease
44 One of the Long term complication of classical E Type I Glycogen Storage Disease galactosemia is
Match: 45 In Type I Glycogen Storage Disease , epinephrine A Glutathione reductase result in
46 Favism may be caused by deficiency of B Increased lactate
47 The Beutler fluorescent spot is a rapid and C erythrocytes inexpensive test to screen for deficiency of
48 Definitive diagnosis of hereditary fructose D Aldolase B. intolerance can be made by assay of activity of
49 Abnormal newborn screening test for galactosemia F Hepatic fructokinase must be followed by a quantitative analysis of galactose-1-phosphate uridylyltransferase (GALT) enzyme activity in
50 Essential Fructosuria results from deficiency of E Glucose-6-Phosphate Dehydrogenase
Good Luck
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