Phenylketonuria

- autosomal recessive
- mutation of phenylalanine hydroxylase (chromosome 12)
- incidence 1:10,000
- inability to convert phenylalanine to tyrosine, results in hyperphenylalaninaemia and increased excretion of its metabolite (phenylketone) in urine
- presents with infantile spasm, developmental delay, musty smelling, pale skin, fair haired and blue eyed, eczema
- Guthrie screening test and measure level of phenylalanine by spectrofluorometric methods
- management: restriction of dietary phenylalanine with tyrosine supplement