Anonymous asked in Science & MathematicsMedicine · 1 decade ago

Why can PKU disorder be harmful to someone with PKU?

PKU s a genetic disorder that is caused from a deficiency in a special enzyme that helps break down te amino acid phenylalanine. Can you elaborate on te reason why thisdisorderr can be harmful to some with PKU?

Invent a drug thatstopss this harmful disorder (PKU). What part of the biochemical process would you target? Explain why?

4 Answers

  • 1 decade ago
    Favorite Answer

    PKU is characterized by the inability to break down the amino acid phenylalanine (phe) into another amino acid tyrosine. People who have PKU cannot break down phe, because they have a missing or deficient enzyme. The specific enzyme that is missing or deficient is phenylalanine hydroxylase (PAH). Tyrosine is essential for proper growth and brain development. Because those who have PKU cannot convert phe into tyrosine they risk not getting a necessary amount of tyrosine. When people born with PKU eat something, rather than breaking phe down into tyrosine to send to the brain, their bodies send phe to the brain. This phe accumulates in the blood stream and causes neurological issues.

    Some of the issues that people with untreated PKU can suffer include:

    lack of concentration

    lack of energy

    poor balance




    a mousy odor in their urine

    and in infants who are not treated seizures and mental retardation can result

    All of these symptoms ARE treatable. PKU is detected a few days after birth through a blood test called the Newborn Screening. It is a heel prick that test for various genetic disorders that could be fatal if untreated.

    When people who have PKU are diagnosed they must be put on a low phenylalanine diet. This diet is often called a low protein diet. It excludes meat, dairy, beans, nuts, most grains, and other foods high in protein. People who have PKU mainly eat fruits, vegetables, and sugary foods in measured amounts. They can also buy special foods that are made to imitate breads, pastas, and some meats but they do not have protein in them. The downfall is that most of these foods cost anywhere from three to ten times as much as regular foods do, and they must be ordered online.

    In addition to this very restrictive low protein diet, those born with PKU must drink a special metabolic drink. This drink provides them with the nutrients that they are missing in their diets. Because the twenty amino acids are the building blocks of protein, and people with PKU cannot eat protein, this drink gives them nineteen of the amino acids. The only amino acid it does not contain is phenylalaine.

    People who have PKU must do regular blood test to monitor how much phenylalanine is in their blood.

    As of today the only treatment for PKU is the low protein diet and metabolic drink. There is a new medication called Sapropterin Dihydrochloride (Kuvan). This medication assists in 'kick starting' the enzyme PAH. By doing this Kuvan increases the enzyme activity and allows the body to break down more phenylalanine. This results in the ability to eat more protein without suffering from high phenylalanine blood levels. This helps greatly, because most people who have PKU can only consume 4-10 grams of protein, whereas the average person eats about 60-70 grams of protein a day. Unfortunately for unknown reasons this medication does not work for everyone who has PKU.

    I hope this helps!

    Source(s): Two of my sisters and I have PKU.
  • 1 decade ago

    I've inquired about this subject before being a student of medicine and I found the answer from a genetics professor of mine.

    Phenylketonuria is a disease present in an individual which doesn't have the proper enzyme to break down phenylalanine. When this amino acid builds up in the brain, it causes damage to the brain resulting in mental retardation. The problem with inventing a drug to combat this problem is that you wouldn't need a drug, all you would need would be the enzyme to be present in the brain to break down the amino acid, but the problem is making this enzyme site-specific to the brain.

  • Anonymous
    4 years ago

    previous responses are stable. indicators: via the time indicators are regarded this is too late to evade psychological retardation. Many are honest skinned blondes simply by lack to transform phenylalanine to tyrosine which in turn is switched over to the pigment melanin. Developmental postpone progresses today yet insidiously to psychological retardation and seizures. some sufferers exhibit a musty smell, in lots of cases unappreciated via observers. Ferric chloride will reason the urine to teach a eco-friendly coloration. Affected persons have been before picked up simply by fact there replaced right into a before affected sibling. in recent times all babies undergo screening for a number of to diverse (counting on the state) metabolic ailments. If an toddler is got here upon to have PKU that's placed on a low phenylalanine nutrition ordinary. There must be some PA interior the nutrition ordinary on the grounds that's a mandatory amino acid. a undeniable formula has been better - Lofenac. Older babies are placed on low-phenylalanine meals, in actuality vegetarian. that's a marginally unwell-tasting nutrition ordinary, and there is important non-compliance. In centers the place IQ testing is comprehensive, it relates o.k. with blood phenylalanine ranges. My constrained adventure with PKU is that even properly-controlled babies have situation in math, exceptionally in the event that they circulate off the nutrition ordinary after age six, as some do. some government enable going off the nutrition ordinary at six, others later, and nonetheless others contend which you may desire to stay on the nutrition ordinary for existence. that's quite puzzling for females with PKU who're pregnant to maintain blood ranges low sufficient to have a classic toddler. psychological retardation is an unlucky consequence. (this documents is a minimum of 10 years previous. there may well be new documents considering that then.)

  • 1 decade ago

    Agree with above, the the good news is that this is routinely screened in neonates, and with proper diagnosis and treatment (avoidance of phenylalanine) brain development proceeds normally, and in later, adult life, small amounts of phenylalanine are not likely to render any harm, and the strict diet can be relaxed, somewhat.

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