[Pseudohypoparathyroidism: a generalized and multiple disorder in the adenyl cyclase system]

Pseudohypoparathyroidism (PHP) is caused by non response of target organs (kidney and bone) to parathyroid hormone because of defects in adenylate cyclase-system. The often seen combination of other endocrine abnormalities with PHP speak for a generalized defect of hormonsensitive adenylate cyclases, but not for isolated resistance to parathyroid hormone. At least two defects are known: in Typ I-PHP the defect is before the formation of cyclic AMP (cAMP) because of a reduced activity of receptor-cyclase coupling protein. In Typ II-PHP the defect lies behind cAMP-formation (defect in the reception of cAMP-signal?).