jean robert
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Fraternal twins have episodes of fasting hypoglycemia, hypoketonemia, and muscle weakness occurring only during periods of caloric deprivation. One twin at 5 months of age. The surviving twin develops a cardiomyopathy, which is diagnosed at 3 years of age. Carnitine esters are elevated in muscle tissue and in serum. Which of the following is the most likely diagnosis?
a.-alpha -L-iduronidase deficiency
b.- Acid maltase (or alpha 1,4 glucosidase) deficiency
c.-Carnitine uptake deficiency
d.- Overactive hormone sensitive lipase Long-chain acyl dehydrogenase (LCAD) deficiency
e.-Muscle glycogen phosphorylase deficiency
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| sigh
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C.
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| jean robert
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Hint: Carnitine esters are elevated in muscle tissue and in serum.
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| sigh
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E?
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| Tiff
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D
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| jean robert
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EXPLANATION
Correct answer is D
Each of the genetic deficiencies listed may present with cardiomyopathy in childhood. LCAD affects the 1st step in Beta oxidation of fatty acids in the mitochondria. Cardiac muscle and resting skeletal muscle use fatty acids and ketones as a primary energy source, thus in LCAD deficiency,muscle weakness and eventually cardiomyopathy develop.FASTING HYPOGLYCEMIA and HYPOKETOSIS ocurring together are strongly suggestive of a block in fatty acid oxidation.
ONLY a Carnitine uptake deficiency or LCAD deficiency are related to fatty acid oxidation. Since carnitine esters (long chain acyl carnitines) are accumulating in serum and muscle tissue, a carnitine uptake deficiency is ruled out.
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Great works are performed not by strength, but by perseverance.
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