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Essay about Phenylketonuria

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Phenylketonuria Phenylketonuria, otherwise known as PKU, is a rare genetic disease that is caused by a person’s body being unable to metabolize the amino acid phenylalanine. The disease can cause mental retardation because the build up of phenylalanine in the body. When phenylalanine is not broken down and turned in a different amino acid, tyrosine, it can create other enzyme routes that build up in the blood stream and body tissue. This can be extremely harmful to the body and its development. This disease is caused by missing the enzyme phenylalanine hydroxylase, this enzyme is the one that normally breaks down phenylalanine. It is rare for this enzyme to be completely absence, but this form leads to the most severe mental…show more content…
PKU is passed on in a “autosomal recessive” gene. This means that a person may have one of the genes for the disease but if they have the other dominant gene they will not be affected by the disease. In the diagram ‘P’ is the dominant gene and ‘p’ is the recessive gene. People who have one recessive gene and one dominant gene ‘Pp’ are called silent carriers. The person with ‘PP’ does not have any of the PKU gene. The person with ‘pp’ has PKU. Each time two carriers reproduce the chances the baby of having PKU is 25%. The chances of them being a silent carrier is 50%. One in every about fifty people in the general population are carriers. And the chances of that carrier’s mate is a carrier is about one in 2500. PKU occurs in about one of out every 10,00 babies born in the United States. Incidents of this disease occur equally in male and female babies. (Schuett) Screening for PKU is now done in every state for all newborn babies. The test, called the heel stick test, is done at about three days old, to get early detection. Early detection is the key when treating PKU. If at an early age the baby’s diet is changed to avoid phenylalanine, a baby who was once destined to become severely mental retarded, now can live their lives fully without any symptoms of the disease. A baby who has PKU must immediately be kept away from foods containing protein, because protein contains high levels of
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