Zusammenfassung der Ressource
Newborn screening
- heel prick test- spot of
blood onto filter paper
- phenylketonuria
- UK incidence=
1 in
10,000-15,000
births
- pathology
- deficiency of
phenylalanine
hydroxylase
- classical PKU
- defect in synthesis or
recycling of biopterin
cofactor of
phenylalanine
hydroxylase
- presentation
- developmental delay
@ 6-10 months of
age
- untreated PKU
- musty odour
- due to phenylactic acid (a metabolite)
- fair-haired,
blue-eyed kids
- eczema
- seizures
- Mx
- Rx: dietary restriction
of phenylalanine
- but enough for
optimal physical
and neuro
growth
- maintain throughout life
- imp during pregnancy
- high maternal fetal
phenylalanine
damages fetus
- regularly monitor blood
phenylalanine
- cofactor defects
- poorer prognosis
- Rx: diet low in
phenylanine and
neurotransmitter
precursors
- hypothyroidism
- cystic fibrosis
- haemoglobinopathies
- MCADD
- homocystinuria
- pathology
- cystathionine
synthetase
deficiency
- presentation
- developmental
delay
- evenutally
subluxation of lens
(ectopia lentis)
- progressive learning difficulty
- psychiatric disorders
- convulsions
- Marfan's syn like
skeletal
manifestations
- fair
complexion
and brittle
hair
- thromboembolic
episodes @ any
age
- Rx
- large doses of
coenzyme
pyridoxine
- if poor response to pyridoxine
- low methionine diet w/
cysteine supplementn
- + betaine (re-methylating agent)
- tyrosinaemia
- rare
- autosomal
recessive
- pathology
- fumarylacetoacetase def
- toxic metabolites build up
- -> liver damage
- -> liver failure
- -> renal tubules
- Falconi syndrome
- fatal if untreated
- Rx
- NTBC
- inhibits enzyme vital to tyrosine catabolism
- low tyrosine and phenylalanine in diet