Fatty Acid Oxidation Disorders

Question 1

Sweaty feet, acrid urine

Answer 1

Glutaric acidemia type II

Question 2

Is the only genetic defect in which carnitine deficiency is the cause, rather than the consequence of impaired fatty acid oxidation

Answer 2

Primary carnitine deficiency

Carnitine Transport Deficiency

Question 3

Progressive cardiomyopathy (heart uses fatty acid at rest and switches to glucose only during stress)

With or without skeletal muscle weakness at 1 year

Extremely reduced carnitine in plasma and muscle
1-2% normal

Answer 3

Carnitine Transport Defect

Question 4

Treatment of Carnitine Transport Deficiency:

Answer 4

Oral carnitine at 100-200 mg/kg/d

Corrects impairment in fasting ketogenesis

Question 5

Autosomal Recessive
Chromosome 9q34.1

Neonatal/severe form is most common

Neonatal screening for urea cycle defect has disclosed affected patient who are asymptomatic

Answer 5

Citrullinemia

Question 6

Appears within the first few days of life with hyperammonemia

Labs are similar to patient with OTC deficiency except

Plasma citrulline levels are 50-100x normal in Type I vs OTC

Answer 6

Citrullinemia

Question 7

Too much ammonia, urea and H (CO2) in the blood leads to formation of

Answer 7

GABA hence inhibited brain

Question 8

Most common fatty acid oxidation disorder

Answer 8

Medium chain acyl coa dehydrogenase deficiency

Question 9

First 3 months to 5 years with acute illness triggered by prolonged FASTING

Vomiting, lethargy, coma, seizures, respiratory collapse

sudden infant death

There is frequently a history of a previous sibling death due to unrecognized MCAD deficiency

Answer 9

Medium chain acyl coa dehydrogenase

Question 10

MCAD treatment

Answer 10

Acute: IV fluids 10% dextrose to prevent hypoglycemia and to supress lipolysis

Chronic: avoiding fasting, overnight limit fasting 10-12 hours