Types include: ;Type 1a (OMIM ) : Has a characteristic phenotypic appearance (Albright's hereditary osteodystrophy), including short fourth and fifth metacarpals and a rounded facies. It is most likely an autosomal dominant disorder. It is also associated with thyroid stimulating hormone resistance. Caused by GNAS1 mutation. ; Type 1b (OMIM ) : Lacks the physical appearance of type 1a, but is biochemically similar. It is associated with a methylation defect in the A/B exon of GNAS1, caused by STX16 disruption. ; Type 2 (OMIM ) : Also lacks the physical appearance of type 1a. Since the genetic defect in type 2 is further down the signalling pathway than in type 1, there is a normal cAMP response to PTH stimulation despite the inherent abnormality in calcium regulation. The specific gene is not identified. While biochemically similar, type 1 and 2 disease may be distinguished by the differing urinary excretion of cyclic AMP in response to exogenous PTH. Some sources also refer to a "type 1c" (OMIM ). The phenotype is the same as in type 1a, but red blood cells show normal Gs activity. As it is also caused by a GNAS mutation, it is not clear whether it should be considered an entity separate from Ia.
Pseudohypoparathyroidism
Pseudopseudohypoparathyroidism
Hypoparathyroidism
X-linked recessive hypoparathyroidism
Secondary hyperparathyroidism
Tertiary hyperparathyroidism
Primary hyperparathyroidism
X-linked hypophosphatemia