Newborn screening

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

Next up

Newborn screening

Description

Resource summary

Similar

	Created by v.djabatey over 10 years ago