On the Xtreme Cuts and Xtreme Energy label it has a warning about Phenylketonurics and to seek medical advice if symptoms persist. What is Phenylketonurics and should I be concerned about it?
Phenylketonurics or Phenylketonuria (PKU) is a genetic disorder that is characterized by an inability of the body to utilize the essential amino acid, phenylalanine. Amino acids are the building blocks for body proteins. 'Essential' amino acids can only be obtained from the food we eat as our body does not normally produce them. In 'classic PKU', the enzyme that breaks down phenylalanine, phenylalanine hydroxylase, is completely or nearly completely deficient. This enzyme normally converts phenylalanine to another amino acid, tyrosine. Without this enzyme, phenylalanine and its' breakdown chemicals from other enzyme routes, accumulate in the blood and body tissues. Although the term 'hyperphenylalaninemia' strictly means elevated blood phenylalanine, it is usually used to describe a group of disorders other than classic PKU. These other disorders may be caused by a partial deficiency of the phenylalanine breakdown enzyme or the lack of another enzyme important to the processing of this amino acid. A normal blood phenylalanine level is about 1 mg/dl. In classic PKU, levels may range from 6 to 80mg/dl, but are usually greater than 30mg/dl. Levels are somewhat less in the other disorders of hyperphenylalaninemia. Chronically high levels of phenylalanine and some of its breakdown products can cause significant brain problems. Classic PKU is the most common cause of high levels of phenylalanine in the blood. Classic PKU and the other causes of hyperphenylalaninemia affect about one of every 10,000 to 20,000 Caucasian or Oriental births. The incidence is declining and in African Americans it is far less. These disorders are equally frequent in males and females. PKU and the other causes of hyperphenylalaninemia are inherited in a recessive fashion. This means an affected person inherited two traits for the disorder (e.s., one from each parent). A person with one trait for the disorder, is called a 'carrier' for PKU. Carriers do not have symptoms of the disorder. By law we must state this disorder on the container if the supplement contains phenylalanine, even though a very small amount of the population may have this genetic defect. If you have not got PKU, then disregard the warning on the label.