What is Tyrosinemia?
Tyrosinemia is a protein degradation causing the accumulation of highly toxic products, specially succinylacetone, in plasma, urine and tissues.
How do proteins degrade?
Proteins are formed by a very long amino-acid chain (tyrosine) among them liberated when proteins degrade. Liberated amino acids may be used to create other new proteins of our organism or to generate energy. Each amino acid degrades, at the same time trhough a a series of chain reactions, creating metabolic routes, so each aminoacid has its own route to form and to degrade becoming energy. All of these reactions occur thanks to the action of some proteins, enzymes, that enable them.
What is a metabolic disorder?
When a metabolic disorder exists, some of these reactions are not produced with the due efficiency and the previous compunds to the reaction accumulate, while the posterior do not synthesize correctly.
What happens with Tyrosinemia?
Tyrosinemia is a tyrosine metabolic disorder caused by the defiency of an enzyme, fumarylacetoacetate hydrolase (FAH).Due to this some aminoacids such as tyrosine and methiotine and some toxic substances such as succinylacetonees, which at the same time inhibits porfirine metabolism, accumulate.
Why do we say this disorder is congenit?
We say this disorder is congenit because we are born with it because it is hereditary. Each of the reactions of the metabolism concerning the compounds that form our body is genetically determined (encoded). We all inherit from our parents the correct or altered information that determines what will be for every metabolic reaction. If we inherit an errouneous or partially altered information, that precise point will work badly and a congenit metabolic disorder may appear.
What happens if a child is born with tyrosinemia?
The baby is born without problems because until delivery his mother metabolzes the proteins, and she does so correctly even if she actually is the bearer of an erroneous information. When the baby begins to feed, the milk proteins degrade and liberate all aminoacids. Tyrosine does not degrade properly due to the enzymatic defect and the already mentioned toxic substances start to accumulate. The child’s liver and kidney slowly get intoxicated with these toxic products and eventually the disorder becomes apparent.
What to do in order to avoid the consequences of a Tyrosinemia?
We must act as quick as possible establishing a SPECIFIC TREATMENT. It is based just in avoiding the accumulation of toxic products, in several ways. On one hand we eliminate from the diet the precursors avoiding their future accumulation. This will be achieved, in the first place, restricting the natural proteins of the diet because all of them contain precursor aminoacids.
However, aminoacids are indispensable for the protein formation that will make up the body of the newborn, so they are introduced through a SPECIAL FORMULA thast does not contain tyrosine nor phenylalanine. Also, we can prevent toxic product formation by means of a medicine NTBC, inhibiting the metabolic route in a previous stage to the formation of the latter. This will preserve the child’s liver and kidney from the toxic action, enabling its correct function.
Tyrosinemia type-I is a hereditary disease that if not treated can imply serious consequences. However, if the enviromental factors are modified. DIET AND EDUCATION of parents and children (in other words, their knowledge), we will manage a NORMAL LIFE for our children, with minimum limitations.
PKU and other Allied Disorders Monitoring Unit
Sant Joan de Déu Hospital