How is pseudohypoparathyroidism type 1B diagnosed?
Pseudohypoparathyroidism (PHP) is a complex condition with extreme variability among affected individuals. The diagnosis is difficult and often delayed due to the different ways that onset of signs and symptoms can occur. Although the onset of signs and symptoms may be related to severe hypocalcemia leading to seizures or fainting episodes, the condition may only become evident during major growth spurts, when calcium requirements are higher.
The diagnosis of PHP type 1B is generally based on clinical features (signs and symptoms, and physical exams) and biochemical findings from a blood test for calcium-phosphate metabolism (which includes calcium, phosphate, magnesium and parathyroid hormone (PTH) serum measurements) in order to distinguish PHP from other conditions. PHP type 1B can be distinguished from types 1A and 1C by the absence of Albright's hereditary osteodystrophy (AHO) which occurs in types 1A and 1C, and in most cases, hormonal resistance being limited to PTH. Molecular genetic testing has also become a reliable way to differentiate between the various subtypes of PHP.
Last updated: 7/9/2013
Is genetic testing available for pseudohypoparathyroidism type 1B?
Yes. The Genetic Testing Registry (GTR) provides information about the genetic tests for pseudohypoparathyroidism type 1B. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.
Last updated: 7/8/2013
How can I find a genetics professional in my area?
Valentina Donghi, Stefano Mora, Ilaria Zamproni, Giuseppe Chiumello and Giovanna Weber. Pseudohypoparathyroidism, an often delayed diagnosis: a case series. Cases Journal. 2009; http://www.casesjournal.com/content/2/1/6734. Accessed 7/9/2013.