Phenylketonuria Disease

Phenylketonuria disease is a disorder caused by the formation of the amino acid phenylalanine, which is an essential amino acid that can not be synthesized by the body but there is the food. Excess phenylalanine is usually transformed into tyrosine, another amino acid, and aside from the body. Without the enzyme that converts it to tyrosine, phenylalanine becomes more developed in the blood and becomes toxic in the brain, causing mental retardation.

PKU occurs in almost all ethnic groups. If PKU occurs in families and can be found DNA from an affected family member, making amniotic fluid or chorionic villus sampling with DNA analysis can be done to decide whether the fetus has abnormalities.


Most occur in newborns was detected during routine screening tests. Newborns with PKU rarely have symptoms right away, although sometimes a baby is drowsy or feed poorly. If untreated, affected infants progressively develop mental retardation in the first year of life, which eventually became severe. Other symptoms include dizziness, nausea and vomiting, spotting such as eczema, skin and hair than their family members, aggressive or injurious behavior, hyperactivity, and sometimes psychiatric symptoms. Untreated children often remove body odor and urine "Mousy" due to the results of phenylalanine (phenylacetic acid) in urine and sweat.

To prevent mental retardation, phenylalanine intake should be limited (but not eliminated as a whole because people need some phenylalanine to live) at the start in the first few weeks of life. Since all natural sources of protein contain too much phenylalanine for children with PKU, so children should not eat meat, milk or other foods that contain protein. Instead, they must eat-phenylalanine is not the kind of foods, especially artificial. Low-protein natural foods, like fruits, vegetables, and grains of certain plants with a restricted number, can be eaten.

Dietary restrictions, if started early and maintained properly, allows for normal development. However, if the controls are very strict diet is not maintained, affected children may begin to experience difficulties in school. Dietary restrictions started after 2 to 3 years to control hyperactivity and extreme ignorance and increase the IQ of children in the end but did not reverse the mental retardation. New evidence suggests there are some functions of mentally retarded adults with Phenylketonuria (born before newborn screening tests exist) might be improved if they followed the diet Phenylketonuria.