TYROSINOSIS (tyrosinosis; tyrosine + - osis; synonym: inborn tyrosinosis, hereditary tirozinemiya) — the hereditary disease caused by disturbance of exchange of tyrosine, which is shown severe damage of a liver and kidneys.
Baberom is described in 1956 (E. Baber). In a typiform meets seldom; according to La of Du and Essinga (V. of N. La Du, L. R. Gjessing), till 1978 it was known apprx. 100 cases.
T. it is inherited on an autosomal re-tsessivnomu to type. The nature of the metabolic block at it is not established. The insufficiency of an oxidase assumed earlier n-hydroxyphenyl-pyruvic to - you as the reason of metabolic disturbances at T. it is rejected. Many manifestations of T. connect with an imbalance in exchange of amino acids of not clear genesis.
At a pathoanatomical research diffusion cirrhosis, dilatation of renal tubules, dystrophy of the insular device of a pancreas, rachitic changes of a bone tissue are found.
The disease can proceed sharply or chronically.
The wedge, a picture is characterized by symptoms of toxicosis (see. Intoxication ), disorders of function went. - kish. a path, hypostases (see Hypostasis), ascites (see), a gemmorragi-chesky syndrome, increase in a liver and spleen, rakhitopodobny changes of bone system (see. Rickets ). The rapid current of a disease brings into the first weeks of life to a heavy liver failure (see) with a lethal outcome. Cases acute and chronic T. can be observed at members of one family.
The diagnosis is made on the basis by a wedge, pictures and data of a laboratory research. In blood the lowered sugar content, increase in activity of an alkaline phosphatase, and also a high level of tyrosine (see), methionine (see), phenylalanine (see), hydroxyproline (see Proline), serine (see), threonine (see) and other amino acids is noted (see Amino acids). All amino acids in the increased quantities are removed with urine (a generalized aminoaciduria). In urine is defined also n-hydroxyphenyl-lactic, n-hydroxyalpha-toluic and n-hydroxyphenyl-pyruvic to - you. Are characteristic proteinuria (see), a glycosuria (see), a hyperphosphaturia (see. Fosfaturiya ).
The differential diagnosis is carried out with a tranzitorny tyrosinuria, edges it is found approximately in 10% full-term and in 30% of premature newborns and it is caused by a delay of physiological formation of a hepatic oxidase n-hydroxyphenyl-pyruvic to - you. The Tranzitorny tyrosinuria clinically is not shown, removal of tyrosine with urine is normalized in the first months of life.
T. it is necessary to distinguish from the increased content of tyrosine in blood and urine of patients at serious acquired diseases of a liver, e.g. hron. hepatitis (see), the expressed hypovitaminosis With (see. Vitamin deficiency ).
Content of tyrosine in blood and urine increases at a special kind of disturbances of tirozinovy exchange — the essential tiro-zinemiya connected with genetically determined block in exchange of tyrosine owing to insufficiency of enzyme tyrosine-transaminase (there is no cytosolic or soluble fraction of enzyme in a liver). Unlike T. at an essential tirozpnemiya there is no symptomatology from a liver and kidneys, lag of the child in intellectual development, the cataract, a keratohelcosis are observed. T. it is necessary to distinguish from de Tony's syndrome — Debra — Fankoni, at Krom rakhptopodobny changes of bones, a glycosuria, giperaminoatsidurpya, a hyperphosphaturia are observed, however, there are no changes in a liver (see. De Tony — Debra — Fankoni a syndrome ).
Treatment is not developed. Separate cases when it was possible with the help of administration of the protein hydrolyzates containing limited amount of tyrosine and phenylalanine to achieve considerable improvement of the general condition of patients, disappearance of symptoms of damage of kidneys and rakhitopodobny changes of bones are described. However influence of a diet on normalization of functions of a liver is not established yet.
Bibliography: Badalyan JI. The lake, T and au l and V. A. N and In e l t and shch e in Yu. E. - Hereditary diseases at children, page 59, M., 1971; Baber M. D. A case of congenital cirrhosis of the liver with renal tubular defects skin to those in the Fanconi svnd-rome, Arch. Dis. Childh., v. 31, p. 335, 1956; La Du B. N. a. G j e s-s i n g L. R. Tyrosinosis and tyro? ine-mia, in book: The metabolic basis of inherited disease, ed. by J. B. Stanbury a. o., p. 256, N. Y., 1978; Zaleski W. A. a. Hill A. Tyrosinosis, new variant, Ca-nad. med. Ass. J., v. 108, p. 477, 1973,
BB. E. Veltshtsev.