10. Statistics
• 1 per 10,000 - 15,000 newborns are diagnosed
with phenylketonuria in the USA
• Turkey has the highest documented rate in the
world, with 1 in 2,600 births
• Approximately 1 in 35 individuals in Ireland
carry one affected gene.
• Finland and Japan have extremely low rates
with fewer than one case of PKU in 100,000
births.
14. Conclusions
PKU is genetic disease of phenylalanine
metabolism
A low-Phe diet has been a remarkable success in
preventing the devastating brain damage
associated with untreated PKU
Recent times have seen the introduction of a wide
array of novel treatments currently in clinical use
Taken together, the future of PKU treatment has
never looked brighter
Phenylketonuria (PKU), the most common an inborn error of amino acid metabolism, results from an impaired ability to metabolize the essential amino acid phenylalanine PKU is condition in which a baby is born without the ability to properly break down an amino acid called phenylalanine and transform it to tyrosine.
Phenylketonuria (PKU), the most common an inborn error of amino acid metabolism, results from an impaired ability to metabolize the essential amino acid phenylalanine PKU is condition in which a baby is born without the ability to properly break down an amino acid called phenylalanine and transform it to tyrosine.
phenylketonuria can be caused by a deficiency of either phenylalanine hydroxylase or a deficiency of the tetrahydrobiopterin (BH4), the cofactor for the
PHENYLKETONURIA
reaction
The PAH gene encoding for PheOH is located on the long arm of chromosome 12 at locus 22-24.1. The gene spanning 90-100kb contains 13 exons
The two largest categories of PAH mutations causing PKU are missense mutations, which account for 62.6% of all known mutations, and deletions, which account for another 13%.
mutations within PheOH only allow a tolerance of 20 mg/kg/day of Phe in the diet. However, in children with milder forms of PKU or less limiting mutations on PheOH activity up to 50 mg/kg/day of Phe can be tolerated.
This defect results in toxic hyperphenylalanemia from a breakdown in the hydroxylation of phenylalanine (Phe) to tyrosine, the first step in the catabolic metabolism of Phe. This defect causes the symptoms of PKU, which include profound mental retardation and progressive motor dysfunction, which arise from gross imbalances in central nervous system metabolism
If a women with pku is pregnant - closely follow a strick low=phenylalanine diet both before bevoming pregnant and throughout the pregnancy, dinvr nuilf up of this substance will damage the developing baby even if the child has not inherited the defective gene