Young: Medical Genetics - Extended Matching Questions

Table of Contents

1. Chapter 11
   1. Question 1
   2. Question 2

Question 1

Instructions: Each group of extended matching questions consists of lettered options followed by a list of numbered problems/questions. For each numbered problem/question select the one lettered option that is most closely answers the question. You can use the lettered options once, more than once, or not at all.

Theme: Inborn errors of metabolism

Options:

1. Galactosaemia
2. Hurler syndrome
3. Medium chain acyl-CoA dehydrogenase (MCAD) deficiency
4. Ornithine transcarbamylase (OTC) deficiency
5. Phenylketonuria
6. Tay-Sachs disease
7. Zellweger syndrome

Each of the following children has an inherited metabolic disorder. Select the most likely diagnosis for each child from the available options.

1

Scenario 1   A 4-day-old male infant who becomes increasingly sleepy with convulsions and an elevated level of blood ammonia. Choose... Galactosaemia Hurler syndrome Medium chain acyl-CoA dehydrogenase (MCAD) deficiency Ornithine transcarbamylase (OTC) deficiency Phenylketonuria Tay-Sachs disease Zellweger syndrome This history suggests a urea cycle disorder, such as OTC deficiency which shows X-linked inheritance and is usually much more severe in males than in females. Page 212.Incorrect. See Page 212.Your answer has been saved.

2

Scenario 2   A 1-year-old girl with a 4 month history of loss of skills and convulsions. On examination she shows increased tone with an abnormal appearance to her retina. Choose... Galactosaemia Hurler syndrome Medium chain acyl-CoA dehydrogenase (MCAD) deficiency Ornithine transcarbamylase (OTC) deficiency Phenylketonuria Tay-Sachs disease Zellweger syndrome The history of regression points to a neurodegenerative disorder such as Tay-Sachs disease. See Page 215.Incorrect. See Page 215.Your answer has been saved.

3

Scenario 3   A 1-year-old girl who is admitted unconscious two days after the onset of a mild viral illness, which caused her to lose her appetite. Choose... Galactosaemia Hurler syndrome Medium chain acyl-CoA dehydrogenase (MCAD) deficiency Ornithine transcarbamylase (OTC) deficiency Phenylketonuria Tay-Sachs disease Zellweger syndrome This is a very non-specific presentation in a young child. However, the lack of consciousness should raise the possibility of underlying hypoglycaemia. This presentation is typical of MCAD deficiency. See Page 212.Incorrect. See Page 212.Your answer has been saved.

4

Scenario 4   A 1-week-old girl who has a two day history of general malaise with vomiting. Choose... Galactosaemia Hurler syndrome Medium chain acyl-CoA dehydrogenase (MCAD) deficiency Ornithine transcarbamylase (OTC) deficiency Phenylketonuria Tay-Sachs disease Zellweger syndrome Again this is a very non-specific presentation in a neonate. Amongst the listed conditions, galactosaemia is the most likely explanation. Page 209.Incorrect. See Page 209.Your answer has been saved.

5

Scenario 5   A 1-year-old boy with developmental delay, coarse features, and enlargement of the liver and spleen. Choose... Galactosaemia Hurler syndrome Medium chain acyl-CoA dehydrogenase (MCAD) deficiency Ornithine transcarbamylase (OTC) deficiency Phenylketonuria Tay-Sachs disease Zellweger syndrome This boy has features of a storage disorder, such as Hurler syndrome. See Page 124.Incorrect. See Page 124.Your answer has been saved.