PHOSPHATE-DIABETES (synonym: gipofos-
fatemichesky vitamin-B-rezistent-ny rickets, gipofosfatemichesky family rickets) — the hereditary disease caused by disturbance of a reabsorption of phosphorus in renal tubules and which is characterized by rakhitopodobny changes of bone system.
The disease is transmitted on the dominant type linked to a floor. It is possible autosomal dominants - ny a mode of inheritance. Men transmit a disease to daughters, women — equally to children of both floors. The disease develops owing to primary defect in enzymatic systems of the proximal renal tubules participating in a reabsorption of phosphates, hypersensitivity of an epithelium of renal tubules to napam-hormone (see) and also synthesis of the metabolites of vitamin D possessing fosfaturichesky action. The raised excretion of phosphorus with urine (see Fosfaturiya) leads to a hypophosphatemia (see Fosfatemiya), to increase in activity of an alkaline phosphatase (see Phosphatases), to disturbances
of phosphorus-calcium exchange and emergence of bone deformations.
At gistol. a research of a bone tissue disturbance of structure of gaversovy channels and trabeculas is noted; zones of the strengthened formation of ossiform fabric alternate with sites of osteoporosis (see).
The first symptoms of a disease usually appear at the age of 1 — 2 years. The growth inhibition, deformation of a skeleton (Au-shaped curvatures of the lower extremities, rachitic «brasletka» on hands), a hypomyotonia is noted.
The diagnosis is made on the basis by a wedge, pictures, results a lab. researches, data rentgenol. researches of bones. Content of inorganic phosphorus in blood serum — less than 2 mg on 100 ml (norm of 2 — 7 mg on 100 ml) \activity of an alkaline phosphatase by 2 — 4 times exceeds normal indicators, daily removal of inorganic phosphorus with urine can reach 5 g (norm to 1 2 in days). A melituria (see), an aminoaciduria (see) are absent. At rentgenol. a research of bones reveal changes in an epiphysis in the form of expansion of zones of proliferation of a cartilage, coarse-fibered structure of a bone with symptoms of an ossiform hyperplasia, defeat of metaphyses, signs of osteomalacy (see). Differential diagnosis is carried out with rickets (see), other rakhitopodobny diseases (see Tubulopatiya); it is based on identification of a resistant hypophosphatemia.
Treatment is carried out by high doses of vitamin D, since 10 000 — 25 000 ME a day and gradually increasing a dose by 10 000 — 15 000 ME, up to normalization of content of phosphates in blood. Duration of treatment is defined
by the level of activity of an alkaline
phosphatase and dynamics to a rentga
Nol. changes of bones. Treatment is carried out under control of the ABP, content of calcium in urine (see Sul-kovich test) and residual nitrogen to blood. It is necessary to appoint vitamin D in a combination with inorganic phosphates (e.g., neurosin). High therapeutic effectiveness metabolites of vitamin D — 25 hydroxycholecalciferol and 1,25-di-hydroxycholecalciferol possess. At the expressed deformations of a skeleton apply orthopedic treatment.
The forecast for life favorable.
Prevention is directed to early identification F. - and correction of phosphorus-calcium exchange with the purpose of the prevention of bone deformations. At the same time special attention shall be paid to families, in to-rykh there were cases.
Bibliography: Ignatova M. S. and
In e l t and shch ev Yu. E. Nasledstvennye and inborn a nephropathy at children, L., 1978; Shilov A. V. Is also new and - to about in P. V. Differential diagnosis of rakhitopodobny diseases at children, Pediatrics, No. 9, page 65, 1979.
V. P. Lebedev.