Metabolic - General

Question 1

When to consider a metabolic disorder

Answer 1

• Catastrophic neonatal presentation
• Biochemical disturbances
• Liver disease or dysfunction
• Neurologic features
• Myopathy or cardiomyopathy
• Signs of a storage disease

Question 2

Symptoms of Urea Cycle Disorders

Answer 2

Chronic symptoms:
   -Poor feeding, anorexia
   -Protein aversion
   -Vomiting
   \+/- Hypotonia
   \+/- Develop delays

Recurrent acute crises:

• Vomiting
• Lethargy, coma
• Seizures
• Respiratory alkalosis**
• High ammonia

Question 3

Symptoms of Organic Acidemias

Answer 3

Chronic symptoms:
   -Poor feeding,anorexia
   \+/- Protein aversion
   -Vomiting
   -Hypotonia
   -Dev delays/mental retardation

Recurrent acute crises:
   -Vomiting
   -Lethargy, coma
   -Seizures
   -Metabolic ketoacidosis**
   \+/- High ammonia
   \+/- Hypoglycemia

Question 4

Symptoms of Fatty Acid Oxidation Disorders

Answer 4

Clinical:

• Fasting intolerance
• Liver enlargement/dysfunction
• Recurrent vomiting, lethargy, coma
• Long chain defects: Cardiomyopathy, Myopathy

Biochemical:
-Hypoketotic hypoglycemia (not in SCAD)
-Low carnitine
-Abnormal organic acids, acylcarnitines, acylglycines
+/- Hyperammonemia
+/- Hyperuricemia

Question 5

Autosomal Dominant Metabolic Disorders

Answer 5

• Acute intermittent porphyria

- Some Mitochondrial disease

Question 6

X Linked Metabolic Disorders

Answer 6

• OTC deficiency
• Fabry disease
• Lesch-Nyhan disease
• Pyruvate dehydrogenase complex deficiency
• Menkes disease
• Barth syndrome
• Adrenoleukodystrophy
• Hunter syndrome (MPS II)
• Glycerol kinase deficiency

Question 7

Typically Sporadic Mito Disoders

Answer 7

• Kearns-Sayre syndrome

- Pearson syndrome

Question 8

Types of Urea Cycle Disorders (5)

Answer 8

• CPS1 deficiency – AR
• OTC deficiency - **most common and **X-linked
• Citullinemia – AR
• Argininsuccinic aciduria – AR
• Arginase deficiency – AR