Tirozinemiya

Description:

Tirozinemiya — the disease connected with deficit of activity of a fumarilatsetoatsetatgidroksilaza. The "guilty" gene is localized on the 15th chromosome 15q23-q25. Mutations lead to disturbance of metabolism of tyrosine with injury of a liver, kidneys, peripheral nerves. The first struck body is the liver, within the first months of life initial displays of hepatic dysfunction with the remote outcome in cirrhosis and a hepatic carcinoma are noted. As a rule, there is a damage of tubular transport with development of heavy rickets in view of loss of phosphates. At some patients the nephrocalcinosis and a renal failure develops.

Increase of level of tyrosine and methionine in serum cause emergence of a "cabbage" smell from patients.

Tirozinemiya symptoms:

Tirozinemiya of type I is called by insufficiency of enzyme фумарилацетоацетат the hydroxylase leading to heavy pathology of a liver and kidneys, vyzyvyushchy a lethal outcome. The purpose of dietary treatment is the prevention of accumulation of phenylalanine, tyrosine and, in certain cases, methionine, by purpose of a reduced-protein diet. The needs for protein are satisfied with introduction to a diet of the mix of amino acids deprived of tyrosine, phenylalanine and/or methionine. If it is appointed and [NTBC] is used, then protein substitute without phenylalanine and tyrosine is usually used. Mix without phenylalanine, tyrosine and methionine is used only if the patient is not sensitive to [NTBC] or at its absence. While dietary treatment remains significant at a tirozinemiya, [NTBC] exerts the expressed impact on treatment and survival at a tirozinemiya of the I type.

Tirozinemiya of type II is called by a nedostochnost of the tirozinaminotranferaza leading to pathology of eyes, skin disturbances and neurologic complications. The purpose of dietary treatment is the prevention of accumulation of phenylalanine and tyrosine, by purpose of a reduced-protein diet. The needs for protein are satisfied with introduction to a diet of the mix of amino acids deprived of tyrosine and phenylalanine.

Tirozinemiya of type III — very rare form of a tirozinemiya which is shown spasms, an ataxy and mental retardation. The purpose of dietary treatment is the prevention of accumulation of phenylalanine and tyrosine, by purpose of a reduced-protein diet. The needs for protein are satisfied with introduction to a diet of the mix of amino acids deprived of tyrosine and phenylalanine.

Treatment of a tirozinemiya:

The basic in therapy is purpose of the nizkotirozinovy, nizkofenilalaninovy diet leading to reduction of damage of kidneys, however impact of a diet on damage of a liver is less defined. When progressing a disease of the patient transplantation of a liver is shown. However in most cases, progressing of a disease at children with a tirozinemiya of 1 type does not manage to be controlled only one diet. Therefore, today, use of a nitizinon (Orfadin) - the agent suppressing enzyme a 4-gidroksifenilpiruvatdioksigenaza is considered effective treatment. Acute hepatic crises and neurologic crises do not arise at the patients who are on treatment nitizinony.