Utilizamos cookies propias y de terceros para mejorar nuestra web mediante el análisis de tu navegación en nuestro sitio. Si continuas navegando, consideraremos que aceptas su uso. Para más información, consulta nuestro Aviso Legal.

X

Hypophosphatemic Rickets

Features

Defect in renal tubular reabsorption of inorganic phosphate.

Clinical Manifestations

Wide phenotypic variability. Early onset of growth retardation, lower limb deformities and radiological abnormalities. Less frequently observed, bone pain in adults and dental defects secondary to caries and abscesses.

Diagnosis

Clinical and radiological signs of rickets, hypophosphatemia, hyperphosphaturia and high levels of alkaline phosphatase. Normocalcemia with normal PTH ,calcidiol and calcitriol levels. The hypercalciuric form of the disease has high levels of calcidiol and calcitriol.

Genetics

Associated with mutations in four genes: PHEX (dominant inheritance pattern linked to chromosome X), FGF23 (autosomal dominant), DMP1 (autosomal recessive form without hypercalciuria) and SLC34A3 (autosomal recessive form with hypercalciuria). For the genetic study it will be necessary samples of the index case and the parents.

Treatment

Oral phosphate salts several times a day and vitamin D derivatives such as calcitriol or alfacalcidiol. In the hypercalciuric form, no vitamin D derivatives are used.

Prognosis

Hereditary dRTA is a permanent circumstance, with an excellent prognosis if therapy is established as soon as possible.

Complications

Por lo general, derivadas del tratamiento con metabolitos de la vitamina D y sales de fosfato (hipercalcemia, hipercalciuria, nefrocalcinosis).

Bibliography

  • Francis F (1995) A gene (PEX) with homologies to endopeptidases is mutated in patients with X-linked hypophosphatemic rickets. The HYP Consortium. Nat Genet 11:130–136.
  • Econs M, McEnery P (1997) Autosomal dominant hypophosphatemic rickets/osteomalacia: clinical characterization of a novel renal phosphate wasting disorder. J Clin Endocrinol Metab 82:674–681.
  • The ADHR Consortium 2000 Autosomal dominant hypophosphataemic rickets is associated with mutations in FGF 23. Nat Genet 26:345–348.
  • Lorenz-Depiereux B, Bastepe M, Benet-Page`s A, Amyere M, Wagenstaller J, Mu¨ller-Barth U, Badenhoop K, Kaiser SM, Rittmaster RS, Shlossberg AH, Olivares JL, Loris C, Ramos FJ, Glorieux F, Vikkula M, Ju¨ppner H, Strom TM (2006) DMP1 mutations in autosomal recessive hypophosphatemia implicate a bone matrix protein in the regulation of phosphate homeostasis.Nat Genet 38:1248–1250.
  • Feng JQ, Ward LM, Liu S, Lu Y, Xie Y, Yuan B, Yu X, Rauch F, Davis SI, Zhang S, Rios H, Drezner MK, Quarles LD, Bonewald LF, White KE (2006) Loss of DMP1 causes rickets and osteomalacia and identifies a role for osteocytes in mineral metabolism. Nat Genet 38:1310–1315.
  • Lorenz-Depiereux B, Benet-Pages A, Eckstein G, Tenenbaum- Rakover Y, Wagenstaller J, Tiosano D, Gershoni-Baruch R, Albers N, Lichtner P, Schnabel D, Hochberg Z, Strom TM (2006) Hereditary hypophosphatemic rickets with hypercalciuria is caused by mutations in the sodium-phosphate cotransporter gene SLC34A3. Am J Hum Genet 78:193–201
  • Tieder, M., Modai, D., Shaked, U., Samuel, R., Arie, R., Halabe, A., Maor, J., Weissgarten, J., Averbukh, Z., Cohen, N., Edelstein, S., Liberman, U. A. 'Idiopathic' hypercalciuria and hereditary hypophosphatemic rickets: two phenotypical expressions of a common genetic defect. New Eng. J. Med. 316: 125-129, 1987.