Question

26. Why did Jessie’s carnitine deficiency cause her to have abnormally low plasma glucose levels at the end of a fasting study, when compared to a healthy person who has fasted for the same length of time?

In the absence of carnitine, the liver stores large amounts of glycogen; absorption of glucose to create these stores depletes blood glucose

Carnitine acts as a hormone and stimulates glucose release from the liver; lack of carnitine results in loss of hepatic glucose production, which leads to hypoglycemia

In the absence of carnitine, fatty acids cannot be used for energy nor can ketone bodies be produced in large quantities; tissues like the muscle, heart, and brain can only utilize glucose under these conditions. This drives excessive glucose uptake from the blood, resulting in hypoglycemia

In the absence of carnitine, fatty acid transport into the mitochondria requires a large amount of ATP; to produce the additional ATP required, the liver must oxidize glucose, which depletes glycogen stores, causing hypoglycemia

In the absence of carnitine, Jessie’s muscles could not use fatty acids as substrates for glycolysis

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27. A deficiency of a particular protein in the liver causes the liver to become enlarged and fatty and causes a reduction of ketone bodies in the blood. In the muscle, deficiency of this same protein causes recurrent muscle weakness, especially during fasting or exercise. This protein is normally found on the outside surface of the outer mitochondrial membrane. It normally releases free CoA as one of its products. People with this deficiency would be particularly sensitive to some of the side effects of valproic acid. What is this protein?

Citrate synthase

Carnitine acyltransferase I

Carnitine acyltransferase II

Hormone-sensitive lipase

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28. Is there anything about Jessie that would make her particularly sensitive to the side effects of valproic acid or was her carnitine deficiency just a rare and accidental occurrence?

No, Jessie is just unlucky but there is nothing else about her that contributed to this problem

Yes, Jessie is not likely getting adequate carnitine in her diet

Yes, Jessie is a type 2 diabetic

Yes, Jessie has an inborn error of metabolism that affects lipid transport

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29. Based on all the evidence you have gathered in this case, and your answers to previous questions, what do you think caused Jessie’s fainting episode? (Select ALL the relevant factors that should be included in a complete explanation of her biochemical/medical issues!)

Jessie’s medication

Jessie’s diet in the days leading up to the episode

Jessie is a type 2 diabetic

Jessie’s diet the day of the episode

Jessie has an inborn error of metabolism that affects lipid transport

Jessie is a type 1 diabetic

Jessie has chronic hypoglycemia and as a result an inability to adequately metabolize most fatty acids

Jessie lost consciousness due to severe hypoglycemia because the overexertion from her swim further depleted her blood glucose

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30. If she does not deal with her carnitine deficiency, what future health problems do you predict for Jessie?

An increase in ketones during any fasting periods

The development of type 2 diabetes as she ages

Increased levels of β-oxidation, leading to fat deposits in the muscle and liver cells

Low levels of fatty acids in the blood due to Jessie’s inability to mobilize fatty acids from adipose tissue

Because of a build-up of fatty acids in the blood, she may have pathological deposits of fat in liver and muscle tissues

Answer 1

26)In the abscena of carnitine the muscles will not be able to use the fatty acid as a substrate and glycolysis and there by decreasing blood glucose levels

27) carnitine acetyltrandferace 1 deficiency leads to fatty liver

28) Usually carnitine deficiency can occur if there is genetic mutation and due yi inborn error of metabolism affecting lilil transportation

29)She may have an in born error,her diet and chronic hypoglycemia due to difficulty in metabolising fatty acids