Characteristic Height Growth Pattern in Patients with Pseudohypoparathyroidism: Comparison between Type 1a and Type 1b

Pseudohypoparathyroidism (PHP) is a metabolic disorder characterized by organ resistance to the action of parathyroid hormone. PHP type 1 is subclassified into two apparent disorders, type 1a (PHP1a) and type 1b (PHP1b). Patients with PHP1a show Albright hereditary osteodystrophy including short stature. Patients with PHP1b have no such skeletal defects, however, literature regarding the growth of PHP1b is not currently available. We evaluated growth charts of PHP patients, including four PHP1a patients and six PHP1b patients. Growth patterns were different between PHP type 1a and 1b. Adult height was abnormally low in all PHP1a patients. The growth pattern of PHP1a was characterized by mild growth impairment in the prepubertal period, a blunted growth spurt and premature cessation of the growth spurt. The adult height of male PHP1b was slightly lower than average. An early growth spurt was observed only in male patients with PHP1b and it may reduce the adult height of male patients with PHP1b. This warrants further investigation into the growth and pubertal development of PHP1b patients.