Pseudopseudohypoparathyroidism

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Obesity, Sleep & Internal medicine
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Pseudopseudohypoparathyroidism
Protein GNAS
Synonyms
Pronounce	N/A
Specialty	N/A
Symptoms	Short stature, round face, subcutaneous ossifications
Complications
Onset
Duration
Types
Causes	Genetic mutation in the GNAS complex locus
Risks
Diagnosis	Clinical evaluation, genetic testing
Differential diagnosis	Pseudohypoparathyroidism, Albright's hereditary osteodystrophy
Prevention
Treatment	Symptomatic management
Medication
Prognosis	Generally good
Frequency	Rare
Deaths

Pseudopseudohypoparathyroidism (PPHP) is a rare inherited disorder, closely related to Albright's hereditary osteodystrophy (AHO). It is characterized by physical features that resemble those seen in hypoparathyroidism, but without the biochemical abnormalities associated with it.

Signs and Symptoms

Patients with PPHP typically exhibit features of AHO, such as short stature, obesity, round face, subcutaneous calcifications, and brachydactyly. However, they do not show the resistance to parathyroid hormone seen in pseudohypoparathyroidism (PHP).

Genetics

PPHP is caused by mutations in the GNAS1 gene, which encodes the alpha subunit of the stimulatory G protein. This protein plays a crucial role in the regulation of cellular responses to hormones. The mutations in PPHP are inherited in an autosomal dominant manner, meaning one copy of the altered gene in each cell is sufficient to cause the disorder.

Diagnosis

The diagnosis of PPHP is based on clinical features and genetic testing. The presence of AHO features without biochemical evidence of hypoparathyroidism is suggestive of PPHP. Genetic testing can confirm the diagnosis by identifying a mutation in the GNAS1 gene.

Treatment

There is no specific treatment for PPHP. Management is symptomatic and supportive, focusing on controlling the symptoms and improving the quality of life. This may include physiotherapy for mobility issues, and psychological support for any associated mental health issues.

See Also

• Albright's hereditary osteodystrophy
• Pseudohypoparathyroidism
• Hypoparathyroidism