When mutations occur on the maternally inherited alleles expressed in the thyroid or pituitary glands and the renal proximal tubule, a resistance develops to parathyroid hormone (PTH) and other hormones that signal through the Gαs-coupled receptors generating disease (pseudohypoparathyroidism type 1A). This evidence concerns the gene PTH and pseudohypoparathyroidism type 1A.