Congenital Hyperphosphatemic Conditions Caused by the Deficient Activity of FGF23.

Congenital diseases that could result in hyperphosphatemia at an early age include hyperphosphatemic familial tumoral calcinosis (HFTC)/hyperostosis-hyperphosphatemia syndrome (HHS) and congenital hypoparathyroidism/pseudohypoparathyroidism due to the insufficient activity of fibroblast growth factor (FGF) 23 and parathyroid hormone. HFTC/HHS is a rare autosomal recessive disease caused by inactivating mutations in the FGF23, UDP-N-acetyl-alpha-D-galactosamine:polypeptide N-acetylgalactosaminyltransferase 3 (GALNT3), or Klotho (KL) genes, resulting in the excessive cleavage of active intact FGF23 (FGF23, GALNT3) or increased resistance to the action of FGF23 (KL). Massive ectopic calcification, known as tumoral calcinosis (TC), is seen in periarticular soft tissues, typically in the hip, elbow, and shoulder in HFTC/HHS, reducing the range of motion. However, other regions, such as the eye, intestine, vasculature, and testis, are also targets of ectopic calcification. The other symptoms of HFTC/HHS are painful hyperostosis of the lower legs, dental abnormalities, and systemic inflammation. Low phosphate diets, phosphate binders, and phosphaturic reagents such as acetazolamide are the treatment options for HFTC/HHS and have various consequences, which warrant the development of novel therapeutics involving recombinant FGF23.

Congenital PCB poisoning: a reevaluation.

A review of the literature reveals a need to clarify the pathologic physiology of congenital polychlorinated biphenyl (PCB) poisoning, which is characterized by intrauterine growth retardation, brown staining of the skin and mucous membranes, as in Addison's disease, natal teeth, widely open fontanelles and sagittal suture and apparent overgrowth of the gingiva. The skull abnormalities may represent irregular calcification, with natal teeth appearing because the bone of the mandible is penetrated more easily than usual. Some fetuses were poisoned at the time the mothers ingested the oil; others were affected in the subsequent years from residual contamination in the mothers' bodies. The misadventure in Japan was repeated in Taiwan in 1979. The seven congenital cases in Taiwan reported thus far seem to differ from those in Japan. In Taiwan the noses were somewhat black, two of the infants did not have low birth weight and the osseous abnormalities of the skull and gingival hyperplasia were not observed. Systematic followup studies should be made in Taiwan of the children born within 2 years of maternal poisoning with PCBs. Special attention should be given to age at first dentition and skull X-rays for spotty calcification, among other measures of physical, neurologic and intellectual development.

Subepidermal calcified nodule.

The subepidermal calcified nodule (SNC), included under the idiopathic cutaneous calcifications, is an infrequent cutaneous process. We report a new case localized on the chin of an 18 month old child. We review the concept gathered from previous literature and we post the possible role which the mast cell may play in the genesis of the said deposits.