Pseudohypoparathyroidism is an inherited disorder associated with resistance to the action of several hormones, including parathyroid hormone, thyroid-stimulating hormone, follicle-stimulating hormone, and luteinizing hormone. The disorders described under this designation are heterogeneous in regard to the underlying genetic defects, the phenotypic manifestation, and the severity of the defects in hormone action. The majority of affected individuals who also have the characteristic skeletal changes (heredity osteodystrophy) have a defect in the guanine nucleotide regulatory protein (G protein) that is essential for coupling certain cell-surface hormone receptors to the adenylate cyclase system. This defect is probably the cause for resistance to the action of multiple hormones. In the remaining patients the cause for hormone resistance has not been identified.
Thyroid Stimulating Hormone Resistance