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Old 07-02-2011
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Question Mechanism of hypoglycemia in hereditary fructose intolerance

Can anyone explain mechanism of hypoglycemia in hereditary fructose intolerance



thanks in advance




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Default Fructose intolerance

The issue with both fructose intolerance and galactokinase deficiency is that the site at which the reaction is stopped yields a product that contains phosphate.

Fructose intolerance--Deficiency of Aldolase B----
Accumulation of Fructose 1 Phosphate

Classic galactosemia----Deficiency of Galactose 1 phosphate urydil transferase--
Accumulation of Galactose 1 Phosphate

The sequestration of phosphate by this two products creates a lot of problems in the body metabolism, since phosphate is a much needed substance, their would be inhibition of gluconeogenesis and glycogenolysis, and of course of ATP(adenosine tri phosphate).

Last edited by NGaleas; 07-02-2011 at 10:41 AM.
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Quote:
Originally Posted by NGaleas View Post
The issue with both fructose intolerance and galactokinase deficiency is that the site at which the reaction is stopped yields a product that contains phosphate.

Fructose intolerance--Deficiency of Aldolase B----
Accumulation of Fructose 1 Phosphate

Galactokinase deficiency----Deficiency of Galactokinase---
Accumulation of Galactose 1 Phosphate

The sequestration of phosphate by this two products creates a lot of problems in the body metabolism, since phosphate is a much needed substance, their would be inhibition of gluconeogenesis and glycogenolysis, and of course of ATP(adenosine tri phosphate).

Galactokinase defficiency doesnt produce galactose 1-P (its galactose 1-P uridyl transferase defficiency that traps Gal 1-P intracellulary)

i found the same explanation in kaplan and FA but for galactose case there is not mentioned hypoglycemia
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You're right, i messed up galactokinase deficiency with classic galactosemia.
But the issue, is that the sequestration of phosphate is what causes all the mayhem. If you follow up both fructose metabolism and galactose metabolism, the end is to continue with glycolisis and gluconeogenesis. If this pathways are not continued you'll end up with hypoglycemia.
Even though first aid doesn't annotate that classic galactosemia has hypoglycemia, it does.
http://health.state.tn.us/nbs/PDFs/Galactosemia2.pdf
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thanks

i got confused cause neither kaplan nor FA mentioned it

and hypoglycemia was applied just on fructose alone
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You`re welcome. It happens to me a lot, qbanks have definitely open up the world for me, many concepts get cleared when working with them.
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Originally Posted by NGaleas View Post
You`re welcome. It happens to me a lot, qbanks have definitely open up the world for me, many concepts get cleared when working with them.

it seems not quite right
Here is my understanding,PLS correct me if I am wrong

during gluconeogenesis and glycogenolysis,both needs ATP to process the reaction
since G1P and F1P trapping phosphate, there will be no enough energy (phosphate) for generate glucose from both pathway
there for......hypoglycemia.........
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