Inborn Errors Of Metabolism Flashcards
What does phenylkentonuria do
Causes an excess in phenyl-ketones in urine
Inability to metabolise phenylalanine
So excess in urine
Build up in blood
What is phenylkentonuria
And what enzyme is affected
Autosomal 12 recessive disorder
Enzyme affected is
phenylalanine hydroxylase (PAH)
Consequences of phenylkentonuria
Mental retardation.
Organ damage
Unusual posture
Normal phenylkentonuria
Phe- PAH - Tyr
What happens to oxygen
What happens to bioh4
O2 - h2o
Bioh4 - bioh2
What is bioh4
Cofactors
Bioh2 is converted back to bioh4 by
Dihydropteridine reductase
Mutant phenylkentonuria
Phe not broken down goes into blood and forms
Phenyl pyruvate
Phenyl pyruvate forms
Phenyllkactate
Phenylacetate
Phenylacetylglutamine
Urine harmful biproducts
Phenylkentonuria is a point mutations.
Which type and where
Type 1 2 3
Mutation in intron/exon splice regions
And coding region
PKU type 4 is not due to PAH
What is it due to
It is due to the faulty dihydropteridine reductase
So it doesn’t convert bioh2 to bioh4
Process of phenylkentonuria
Manifests after birth
Mother breaks down phe
Develops hyperphenylalaninaemia a few days after birth
Glycogen conversion 1 in muscles
Glycogen - glucose 1 phosphate
Glycogen phosphorylase
Glucose 1 phosphate - glucose 6 phosphate
Phosphoglucomutase
Glucose 6 phosphate - glucose
Glucose 6 phosphatase
Glycogen storage disease 1 von gierke disease
What is deficient?
Glucose 6 phosphatase
