Lecture 9 Flashcards
What causes IEM?
Problems arise due to…
defects of single genes that code for enzymes that facilitate conversion of various substrates into products
Problems arise due to..
1.accumulation of substances
which are toxic or interfere with normal function
2.Reduces ability to synthesize essential compounds.
Types of IEM and examples of disorders caused by the IEM type
- Disorders that disrupt the synthesis or catabolism of complex molecules.
-lysosome, peroxisome and intracellular transport and processing disorders
2.Disorders that lead to an acute accumulation of toxic compounds as a result of metabolic block.
-amino acid metabolism disorder, maple syrup urine disease, sugar intolerance
3.Disorders due to a deficiency of energy production or utilisation within the liver, myocardium muscle or brain.
-fatty acid oxidation defects, gluconeogenesis defects.
Inherited metabolic diseases categorised as…
1.Disorders of carbohydrate metabolism
Glycogen storage disease
2.Disorder of amino acid metabolism
maple syrup urine disease.
3.Disorder of lipid metabolism
Medium-chain acyl-coenzyme A dehydrogenase
deficiency (MCADD)
4.Disorder of organic acid metabolism
Alkaptonuria
Glycogen storage disease due to…
Result from a problem that an enzymes involved in the conversion of glucose to glycogen, or the breakdown of glycogen back into glucose is deficient.
Types of Glycogen storage disease, Disease name and the deficient enzymes
Disease Type
Ia
II
III
IV
V
VI
VII
lX
Xl
O
Disease Name VPFAMHTLFL (Very pretty females ate mushrooms, high tea, lollies for life)
Von Gierkes Disease
Pompe’s Disease
Forbes-Cori Disease
Andersens Disease
McArdles Disease
Her’s Disease
Tarui’s Disease
Liver phosphorylation kinase deficiency
Fanconi-Bickel syndrome
Lewis Disease
Deficient Enzyme
Glucose 6 phosphatase
Acid alpha glucosidase
Glycogen debranching enzyme
Glycogen branching enzyme
Muscle glycogen phosphorylase
Liver glycogen phosphorylase
Muscle phosphofructokinase
PHKA2
GLUT2
Glycogen synthase
What is PKU caused by?
Effect of PKU
Inheritance pattern?
Phenylketonuria is caused by lack of the enzyme phenylalanine hydroxylase needed to convert amino acid phenylalanine to tyrosine in the liver.
It is due to a recessively inherited defect in the enzyme. It increases the concentration of the amino acid phenylalanine, and is toxic to the brain, causing intellectual disability.
What is Maple syrup urine disorder
Inheritance pattern?
Distinctive feature?
An autosomal recessive metabolic disorder affecting branched-chain amino acids.
Maple syrup urine disease (MSUD) is a metabolism disorder passed down through families in which the body cannot break down certain parts of proteins.
The condition gets its name from the distinctive sweet odour of affected infants’ urine.
Deficiency of _______ causes MSUD
Leads to accumulation of?
Metabolic disorder caused by a deficiency of the branched-chain alpha-keto acid dehydrogenase complex (BCKDC) enzyme.
This leading to a accumulation of the branched-chain amino acids (leucine, isoleucine, and valine) and their toxic by-products in the blood and urine
What is Alkaptonuria?
Caused by?
Recessive or dominant genetic mutation
Alkaptonuria is caused by a recessive genetic mutation.
Alkaptonuria is caused by the lack of an enzyme called homogentisic dioxygenase (HGD) in which patients cannot fully break down a toxic acid called homogentisic acid, or HGA.
Alkaptonuria key symptom
Black urine
Medium-chain acyl-coenzyme A dehydrogenase deficiency due to defects in ….
Purpose of the enzyme..
Fatty acid oxidation disorder associated with inborn errors of metabolism.
It is due to defects in the enzyme complex known as medium-chain acyl dehydrogenase (MCAD) and reduced activity of this complex.
This complex oxidizes medium chain fatty acids (Fatty acids having 6-12 carbons) while reducing FAD to FADH2.
