Familial and clinical aspects of calcium pyrophosphate deposition disease.

The mechanisms involved in calcium pyrophosphate dehydrated deposition disease (CPPDD) are unknown and those families with the disease, described in different countries, provide a fertile file for genomic research. Genomic DNA studies in these kindred with secondary or primary form of CPPDD provide a shortcut for trying to investigate the biomolecular basis of the disease. Mutations in the COL2A1 gene have been identified in one family with spondyloepiphyseal dysplasia and secondary deposits of pyrophosphate and apatite crystalline deposits. In another kindred with CPPDD due to precocious osteoarthritis, the phenotype was linked to markers of chromosome 8p. In four other kindreds (British, Argentinean, French, and the United States), the phenotypes were linked to a precise region of chromosome 5p. Two possible genes located in this region that are expressed in the articular cartilage, but of unknown articular physiologic role are being investigated as possible CPPDD genes. From the clinical point of view, CPPDD spectrum of clinical and radiographic manifestations is enlarging, especially those related to spine involvement or pseudo tumoral forms. At the end, the present review of a current therapeutic approach for CPPDD is discussed.