Tyrosinemia
Encyclopedia
Tyrosinemia is an error of metabolism
, usually inborn, in which the body cannot effectively break down the amino acid
tyrosine
. Symptoms include liver and kidney disturbances and mental retardation. Untreated, tyrosinemia can be fatal.
Most inborn forms of tyrosinemia produce hypertyrosinemia (high levels of tyrosine).
There are three types of tyrosinemia, each with distinctive symptoms and caused by the deficiency of a different enzyme.
Metabolism
Metabolism is the set of chemical reactions that happen in the cells of living organisms to sustain life. These processes allow organisms to grow and reproduce, maintain their structures, and respond to their environments. Metabolism is usually divided into two categories...
, usually inborn, in which the body cannot effectively break down the amino acid
Amino acid
Amino acids are molecules containing an amine group, a carboxylic acid group and a side-chain that varies between different amino acids. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen...
tyrosine
Tyrosine
Tyrosine or 4-hydroxyphenylalanine, is one of the 22 amino acids that are used by cells to synthesize proteins. Its codons are UAC and UAU. It is a non-essential amino acid with a polar side group...
. Symptoms include liver and kidney disturbances and mental retardation. Untreated, tyrosinemia can be fatal.
Most inborn forms of tyrosinemia produce hypertyrosinemia (high levels of tyrosine).
Types
- Type I tyrosinemiaType I tyrosinemiaType 1 Tyrosinemia, also known as hepatorenal tyrosinemia, is the most severe form of tyrosinemia. It is caused by a deficiency of the enzyme fumarylacetoacetate hydrolase .-Genetics:...
- Type II tyrosinemia
- Type III tyrosinemiaType III tyrosinemiaType III tyrosinemia is a rare disorder caused by a deficiency of the enzyme 4-hydroxyphenylpyruvate dioxygenase , encoded by the gene HPD. This enzyme is abundant in the liver, and smaller amounts are found in the kidneys. It is one of a series of enzymes needed to break down tyrosine...