Pseudohypoparathyroidism type 1C
Type of disease: Rare conditions
Pseudohypoparathyroidism type 1C is a genetic disorder that resembles hypoparathyroidism (lowered levels of parathyroid hormone), but is caused by a lack of response to parathyroid hormone rather than having too little of the hormone itself. This condition is very similar to hypoparathyroidism, with low calcium levels and high phosphate levels in the blood. This condition is also associated with short stature, a round face, and short hand bones, which is referred to as Albright’s hereditary osteodystrophy. It is distinguished from pseudohypoparathyroidism type 1A because those with type 1C do not have a defect in activity of a particular protein. It is inherited in an autosomal dominant fashion and is caused by a specific mutation in the GNAS gene. Source: Genetic and Rare Diseases Information Center (GARD), supported by ORDR-NCATS and NHGRI.