Description: PKU is very rare but when it happens, it happens because the liver can’t make an essential enzyme called phenylalanine hydroxylase.Symptoms: People who have PKU look normal at birth. They are less attentive, have eating problems, and delayed speech. Many also have heart issues and if they remain untreated they will become hyperactive and lose contact with reality. They may also be less intelligent. By 12 months if the patient is untreated, then it becomes mentally retarded.How common is it: PKU is very rare. Only 1 out of about 15-20,000 people get it.Effects it has on different parts of the body: PKU patients have lighter skin, eyes, and hair than their family and more body odor than normal. They are also more likely to have seizures and heart issues.What population is the most susceptible? It is much more common in Ireland, Scotland, and Finland. Ireland has the highest rates of PKU.Degrees of the disease: There are 3 major types Maternal phenylketonuria, Hyperphenylalaninemia, and Tyrosinemia. Maternal phenylketonuria is when a woman that has untreated PKU passes PKU to her child while it is in the uterus and causes it to become mentally retarded. Hyperphenylalaninemia is when the level of phenylalanine is lower than in PKU. Tyrosinemia is just like PKU except patients not only have high levels of phenylalanine, but also of tyrosine which means their diet must also be lower in tyrosine.Cause and heredity: It is caused by a gene mutation. Since PKU is a genetic disease, it must be given by both parents for the child to have it. But even if both parents have that gene, there is only a 25% chance the kid will. If one parent’s is good and the other is not, then the child will develop normally but its child may have PKU. There is still only a 50% chance of this to happen.Testing used to diagnose the disease: At birth each child has it’s heel pricked and the blood taken from there is tested for PKU.Potential Cure, Prevention, or Treatment currently being used or tested: There is only one treatment for PKU. It is a special diet is started quick enough, it may prevent mental retardation. Since phenylalanine is a necessity, the diet just has lower amounts of it.