Pruebas
A PKU screening test measures the amount of a protein called phenylalanine (Phe) in a sample of a newborn's blood. Phe is in all foods that contain protein such as milk, meats, and nuts. It's also in an artificial sweetener called aspartame. If a newborn has high levels of Phe in their blood, it could mean that they have phenylketonuria (PKU).
For everyone & professionals
Indicadores
The levorotatory isomer of the aromatic amino acid tyrosine. L-tyrosine is a naturally occurring tyrosine and is synthesized in vivo from L-phenylalanine. It is considered a non-essential amino acid; however, in patients with phenylketonuria who lack phenylalanine hydroxylase and cannot convert phenylalanine into tyrosine, it is considered an essential nutrient. In vivo, tyrosine plays a role in protein synthesis and serves as a precursor for the synthesis of catecholamines, thyroxine, and melanin.
Indicadores
One of nine essential amino acids in humans (provided by food), Leucine is important for protein synthesis and many metabolic functions. Leucine contributes to regulation of blood-sugar levels; growth and repair of muscle and bone tissue; growth hormone production; and wound healing. Leucine also prevents breakdown of muscle proteins after trauma or severe stress and may be beneficial for individuals with phenylketonuria. Leucine is available in many foods and deficiency is rare. (NCI04)