Alexandria University Student name: Medical Research Institute Semester: Fall Human Genetics Department Academic year: 2019 – 2020 Degree: Ph.D. in Human Genetics Time allowed: 1 hour Course title: Approach to Specific Disorders II Date: 7 / 11 / 2019 Course code: 1713807 Total marks: 10 Midterm Exam Question No. I: 5 marks (15 minutes) Write short notes on the followings: (2½ marks each) 1- Glucose-Galactose Malabsorption. 2- The most common disorder among sphingolipidoses Question No. II: 5 marks (15 minutes) A. Choose the correct answer: (⅓ mark each) 1-Hurler syndrome results from deficiency of: a-Hexasominidase A enzyme b-Iduronate sulfatase enzyme c-Methionine synthase enzyme d- α-L induronidase enzyme 2 -In galactosemia, cataracts and pseudotumor cerebri are the result of: a- Accumulation of galactitol. b-Inadequate energy production. c-Lack of conversion of galactose to glucose. d-Deficient enzymes. 3-All the following can cause transient neonatal tyrosinemia except: a- Rich protein diet. b- Inherited deficiency of PHPPA dioxygenase enzyme. c- Vitamin C deficiency. d- Premature infant. | Page1 4-Ochronosis in alkaptonuria results from: a-The formation of benzoquinone acetate. b- Formation of alkaptone pigment. c- Deficiency of PHPPA dioxygenase enzyme. d- Increased homogentisate in blood. 5 -The urea cycle is the sole source of endogenous production of a-protein b-arginine c-urea d- body nitrogen 6- Which of the following concerning Tay-Sachs disease is TRUE? a- Substrate-reduction therapy is effective in the acute infantile form b- A combined deficiency of HEX A and HEX B is present in patients' leukocytes c- The nervous system is the main site of pathology d- Ophthalmological evaluation is of no value for diagnosis 7- All the following are true about sialuria EXCEPT: a- Sialuria is a very rare lysosomal disorder b- It is inherited as an AD disorder c- There is abnormal accumulation of sialic acid in the cytoplasm d- Presentation is in infancy with coarse dysmorphic facial features and hepatosplenomegaly. 8- Which of the following are NOT considered to be allelic disorders ? a- Niemann–Pick Disease types A & B b- Tay-Sachs Disease and Sandhoff Disease c- ISSD and Salla disease d- GM1 gangliosidosis and Morquio B syndrome 9- Patients with Niemann–Pick Disease type B ………….. a- usually are Jewish b- have normal intelligence c- never reach adulthood d- all of them have been noted to have “cherry red” maculae | P a g e 2 B. Match each of the following diseases with its description - some choices can be used more than once or may not be used at all: (⅓ mark each) 1. The only lysosomal disorder for which it is useful to A. Metachromatic determine the lysosomal enzyme activity in serum leukodystrophy 2. The disorder for which testing is based on Filipin B. Galactosialidosis staining for abnormal cholesterol morphology 3. A disease characterized by a progressive demyelination, C. Mucolipidosis II which causes severe neurologic symptoms 4. The lysosomal disorder characterized by episodic D. Farber disease painful crises in boys 5. The one LSD not diagnosed by enzyme assay E. Niemann–Pick disease B 6. The lysosomal disease showing combined features of F. Niemann–Pick disease C GM1 gangliosidosis and sialidosis 7. G. Fabry disease 8. H. Gaucher disease | P a g e 3 .