DE TONI-DEBRE-FANKONI SYNDROME ( G. de Toni , ital. pediatrician, sort. in 1895; R. Debre, fr. pediatrician, sort. in 1882; G. Fanconi, Swiss pediatrician, sort. in 1892; syndrome; synonym glyukoaminofosfatdiabt) — the hereditary disease connected with disturbance of processes of a reabsorption in renal tubules of glucose, amino acids, phosphorus and bicarbonates, which is characterized by rakhitopodobny changes of bone system. It is inherited on autosomal recessively type.
The disease is described by J. Tony's de (1933), R. Debra (1934) and G. Fankoni (1936).
De Tony — Debra — Fankoni a syndrome meets in population frequency of 1: 40 000.
An etiology and a pathogeny
the Disease is caused by defect of fermental systems of proximal department of tubules of the kidneys providing processes of a reabsorption of glucose, amino acids, phosphorus and bicarbonates. Loss of amino acids leads to gradual development of dystrophy, delay of dynamics of weight and growth. Owing to removal of large amounts of phosphorus there is a disturbance of processes of a mineralization of a bone tissue, strengthening of a resorption of a bone. In some cases arises hypercalcemia (see). Depletion of an organism amino acids, phosphorus and bicarbonates leads also to development of a metabolic acidosis which strengthens processes of a resorption of a bone tissue, reduces a reabsorption of potassium and calcium in renal tubules and increases removal them. The glycosuria gradually leads to disturbance of regulation of carbohydrate metabolism. As a result of loss with urine of potassium the hypomyotonia develops, tendency to kollaptoidny states appears.
Morfol, changes in kidneys are characterized by flattening of an epithelium of proximal tubules, narrowing of their gleam. In certain cases vacuolation of an epithelium and shortening of proximal department of renal tubules is found.
Clinical symptoms appear at the age of 4 — 6 months; by the end of the 1st and the beginning of the 2nd year of life they become rather expressed. In the beginning the health of the child worsens, he becomes sluggish, adynamic, refuses food, lags behind in weight. Sometimes there is vomiting. Further there are a polydipsia and a polyuria, muscular and arterial hypotonia, a hyporeflexia. Dehydration is possible. Children it is raised are sensitive to infections. Intercurrent diseases are often noted (otitises, sinusitis, pneumonia, etc.). Changes from a skeleton — curvatures of tubular bones, spontaneous changes — are found out when the child starts walking.
the Diagnosis is based on a wedge, signs, laboratory and radiological researches. At a biochemical research of urine the massive aminoaciduria (it is normal to 2 mg/kg of amino nitrogen a day), a glycosuria (it is normal to 132 mg a day), a fosfaturiya is found (it is normal to 20 mg/kg a day). Content of phosphorus, sugar and nitrogen of amino acids in blood is reduced. Besides, the hypochloraemia, a metabolic acidosis with the low content of bicarbonates and the expressed deficit of the bases, in some cases — decrease in content of potassium in blood serum is noted. Activity of an alkaline phosphatase is sharply increased.
Disease differentiate with the acquired damages of proximal tubules by antibiotics (e.g., tetracycline), salts of heavy metals, lysol, cystine, and also with cystinosis (see), glycogenoses (see), galactosemia (see), Lowe's syndrome (see. Lowe syndrome ), from which it differs in a combination of characteristic changes in urine to rakhitopodobny transformations of a skeleton.
At rentgenol, inspection of bone system generalized osteoporosis comes to light.
Treatment includes a dietotherapy — increase in protein content up to 6 g at 1 kg of weight of the child, restriction of carbohydrates, introduction of the products rich with potassium (carrot soup of Moro, raisin, dried apricots, etc.). Vitamin D from 25 000 to 150 000 ME in days together with drugs of phosphorus, 4 — 6 g of sodium citrate is appointed.
The therapeutic effect is estimated on the content in blood of phosphorus and activity of an alkaline phosphatase. It is possible to tell about correction of disturbances of phosphorus-calcium exchange at normalization of activity of an alkaline phosphatase and level of phosphorus in blood not less than 3,5 mg of %. For improvement of processes of bone formation anabolic hormonal drugs are used. In cases of a metabolic acidosis and dehydration symptomatic therapy is carried out. At the expressed deformations of bones operational treatment is shown.
the Forecast at timely begun treatment favorable; gradual recovery of disturbances in carbohydrate, amino-acid and phosphorus-calcium metabolism, improvement of a functional condition of kidneys, disappearance of symptoms of intoxication and rickets is noted that can provide normal development of the child.
See also Tubulopatii hereditary .
Bibliography: Dzhavadzade M. D. and Mamedova Ya. A. K to clinic of a syndrome of de Tony — Debra — Fankoni, Pediatrics, No. 2, page 82, 1972; Ignatova M. S. and Veltishchev Yu. E. Diseases of kidneys at children, page 261, M., 1973, bibliogr.; D e b r e R. e. a. Rachitisme tardif coexis-tant avec une nephrite chronique et une glycosurie, Arch. Med. Enf., t. 37, p. 597, 1934; De T o n i G. Remarks on relations between renal rickets (renal dwarfism) and renal diabetes, Acta paediat. (Uppsala), y. 16, p. 479, 1933; it, Renal rickets with phosphogluco-amino renal diabetes (De Toni — Debre — Fanconi syndrome), Ann. paediat. (Basel), v. 187, p. 42, 1956; Fanconi G. Der frtihinfantile nephro-tisch glykosurische Zwergwuchs mit hypo-phosphatamischer Rachitis, Jb. Kinder-heilk., Bd 147, S. 299, 1936.
V. P. Lebedev, M. F. Logachev.