Mental deficiency in pseudohypoparathyroidism type I is associated with Ns-protein deficiency.
Pseudohypoparathyroidism type I is a hereditary disorder characterized by resistance to parathyroid hormone and other hormones that work via cyclic adenosine 3', 5'-monophosphate (cAMP). Most patients with this disorder have generalized deficient activity of Ns-protein (type Ia), which couples stimulatory hormone receptors to catalytic adenylate cyclase. In patients with normal Ns-protein activity (type Ib), a decreased incidence of resistance to hormones other than parathyroid hormone exists. Mental deficiency of unknown cause occurs in 47% to 75% of all patients with pseudohypoparathyroidism type I. Because mutations in the adenylate cyclase-cAMP system may affect the learning ability of Drosophila flies, we assessed mental deficiency in 25 patients whose Ns-protein activity we had determined: 9 of 14 patients with type Ia disorder and 0 of 11 patients with type Ib disorder had mental deficiency. We suggest that Ns-protein deficiency, reduced cAMP levels, or both, are involved in the mental deficiency in these patients and probably in mental function in humans.
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D005260:Female; D019204:GTP-Binding Proteins / Q000172:deficiency*; D006801:Humans; D007037:Hypothyroidism / Q000209:etiology; D008607:Intellectual Disability / Q000209:etiology* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011547:Pseudohypoparathyroidism / Q000145:classification / Q000378:metabolism / Q000523:psychology*
D019204:GTP-Binding Proteins