FA Metabolism- Brar

Question 1

What is Hypoglycin A? What does it inhibit? What does it cause? What are the symptoms? Who does it affect?

Answer 1

• Rare amino acid (or maybe alkaloid)
• Acyl CoA DH inhibitor (—> inhibits B-Oxidation)
• Leads to fasting hypoglycemia
• Symptoms: vomiting, convulsions, coma
• Affects people with low levels of acyl CoA DH severely

Question 2

What tissues do Beta-Oxidation defects affect?

Answer 2

Compromise tissues which rely heavily on oxidation of FA for energy: Skeletal muscle, Liver during fasting

Question 3

What does carnitine deficiency cause? What 2 pathways does it disrupt?

Answer 3

In liver, leads to HYPOKETOTIC HYPOGLYCEMIA during periods of extended fasting

• During fasting, FA ox is needed to generate acetyl CoA for ketogenesis and ATP for gluconeogenesis
• This deficiency compromises both of these pathways

Question 4

What is medium Chain acyl CoA DH Deficiency? What does this enzyme catalyze? What are the symptoms and when do they present? What circumstances lead to first attack? What kind of mutation causes this defect?

Answer 4

• Most common inherited defect in the β-oxidation sequence
• Affected enzyme catalyzes the first reaction in β-oxidation of medium chain (C5-C12) fatty acids.
• Patients present with FASTING HYPOGLYCEMIA during infancy or childhood:
• Often during an infectious illness when the child eats little
• Many cases go undiagnosed and some infants die during their first hypoglycemic attack (under circumstances suggesting sudden infant death syndrome)
• Most common in NW Europe where a single mutation is responsible for 90% of cases

Question 5

What is Refsum disease? What does it cause the accumulation of? What product results? What are the symptoms?

Answer 5

• Recessively inherited defect of peroxisomal a-oxidation
• Causes accumulation of phytanic acid (branched FA found in plants)
• FA Beta-oxidation yields propionyl CoA rather than acetyl CoA
• Symptoms: slowly progressive peripheral neuropathy, Weakness, Muscle wasting, Retinitis pigmentosa: degeneration of the retina, Cerebellar ataxia

Question 6

What is Apo AI Milano? What does it do?

Answer 6

• Apolipoprotein AI Milano factor.

- Thought to help increase the transport of cholesterol from plaques to liver for reprocessing.

Question 7

What is oleic acid responsible for?

Answer 7

Is responsible for reduction in BP induced by olive oil.