Pyrophosphate arthropathy in hypophosphatasia.

Physiological role of alkaline phosphatase explored in hypophosphatasia.

Hypophosphatasia (HPP) is the instructive rickets or osteomalacia caused by loss-of-function mutation(s) within TNSALP, the gene that encodes the "tissue nonspecific" isoenzyme of alkaline phosphatase (TNSALP). HPP reveals a critical role for this enzyme in skeletal mineralization. Increased extracellular levels of pyridoxal 5'-phosphate and inorganic pyrophosphate (PP(i)) demonstrate that TNSA...

Crystal deposition in hypophosphatasia: a reappraisal.

Six subjects (three female, three male; age range 38-85 years) with adult onset hypophosphatasia are described. Three presented atypically with calcific periarthritis (due to apatite) in the absence of osteopenia; two had classical presentation with osteopenic fracture; and one was the asymptomatic father of one of the patients with calcific periarthritis. All three subjects over age 70 had iso...

Hypophosphatasia: biochemical screening of a Dutch kindred and evidence that urinary excretion of inorganic pyrophosphate is a marker for the disease.

Hypophosphatasia is an inherited disease in which a deficiency of the bone/liver/kidney or tissue nonspecific isoenzyme of alkaline phosphatase (AP; EC 3.1.3.1) occurs. All forms of the disease are characterized clinically by defective mineralization. Several biochemical abnormalities are associated with the deficiency of AP activity, e.g., increased urinary excretion of inorganic pyrophosphate...

Genetic studies of disorders of calcium crystal deposition.

Disordered calcification of cartilage and ligaments occurs commonly amongst the elderly, yet the reasons for this are very poorly understood. Chondrocalcinosis affects 25% of the population aged over 85 yr and 3% of people aged between 65 and 69 yr show radiological evidence of the disease w1x. Diffuse idiopathic skeletal hyperostosis (DISH, Forestier’s disease), which causes ossification of th...

Morphological study of articular cartilage in pyrophosphate arthropathy. (Chondrocalcinosis articularis or calcium pyrophosphate dihydrate crystal deposition diseases).