GTR Home > Conditions/Phenotypes > Tumoral calcinosis, familial, hyperphosphatemic


Hyperphosphatemic familial tumoral calcinosis is a rare autosomal recessive metabolic disorder characterized by the progressive deposition of basic calcium phosphate crystals in periarticular spaces, soft tissues, and sometimes bone (Chefetz et al., 2005). The biochemical hallmark of tumoral calcinosis is hyperphosphatemia caused by increased renal absorption of phosphate due to loss-of-function mutations in the FGF23 or GALNT3 gene. The term 'hyperostosis-hyperphosphatemia syndrome' is sometimes used when the disorder is characterized by involvement of the long bones associated with the radiographic findings of periosteal reaction and cortical hyperostosis. Although some have distinguished HHS from FTC by the presence of bone involvement and the absence of skin involvement (Frishberg et al., 2005), Ichikawa et al. (2010) concluded that the 2 entities represent a continuous spectrum of the same disease, best described as familial hyperphosphatemic tumoral calcinosis. HFTC is considered to be the clinical converse of autosomal dominant hypophosphatemic rickets (ADHR; 193100), an allelic disorder caused by gain-of-function mutations in the FGF23 gene and associated with hypophosphatemia and decreased renal phosphate absorption (Chefetz et al., 2005; Ichikawa et al., 2005). [from OMIM]

Clinical features

  • Increased renal tubular phosphate reabsorption
  • Decreased renal tubular phosphate excretion
  • Conjunctival whitish salt-like deposits
  • Nephrocalcinosis
  • Taurodontia
  • Abnormality of the skin
  • Angioid streaks of the retina
  • Hyperphosphatemia
  • Pulp stones
  • Vascular calcification
  • Hypoplasia of dental enamel
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