Skip to
  1. Homepage
  2. Rare diseases
  3. Search
Simple search

Simple search

(*) mandatory field


Other search option(s)

Pseudohypoparathyroidism type 1C

Synonym(s) -
Prevalence Unknown
Inheritance Autosomal dominant
Age of onset Infancy
  • E20.1
  • C2932716
  • C548076
MedDRA -


Disease definition

Pseudohypoparathyroidism type 1c (PHP1c) is a rare type of pseudohypoparathyroidism (PHP; see this term) characterized by resistance to parathyroid hormone (PTH) and other hormones, which manifests with hypocalcemia, hyperphosphatemia and elevated PTH levels, a constellation of clinical features collectively termed Albright's hereditary osteodystrophy (AHO; see this term), but normal activity of the stimulatory protein G (Gs alpha).


The prevalence is unknown.

Clinical description

Clinical manifestations of PHP1c are similar to those seen in pseudohypoparathyroidism type 1a (PHP1a; see this term). They display the symptoms and signs of AHO (brachydactyly (most often the shortening of the 3, 4 and 5th metacarpals), rounded face, short stature, central obesity, subcutaneous ossifications and variable development delay) as well as PTH-resistance leading to hypocalcemia and hyperphosphatemia, and resistance towards TSH and, sometimes, other hormones.


The exact etiology is unknown as mutations in the GNAS gene (20q13) are only rarely found. Other components of the cAMP-dependent signaling pathway, such as adenylyl cyclase, inhibitory G proteins, or phosphodiesterases might be impaired.

Genetic counseling

In familial cases the disease is inherited autosomal dominantly and genetic counseling is possible.

Expert reviewer(s)

  • Dr Giovanna MANTOVANI

(*) Required fields.

Attention: Only comments seeking to improve the quality and accuracy of information on the Orphanet website are accepted. For all other comments, please send your remarks via contact us. Only comments written in English can be processed.

Captcha image

Detailed information

Review article
Guidance for genetic testing
Get Acrobat Reader
The documents contained in this web site are presented for information purposes only. The material is in no way intended to replace professional medical care by a qualified specialist and should not be used as a basis for diagnosis or treatment.