Pseudohypoparathyroidism is a genetic disorder that is similar to hypoparathyroidism. However, it is caused by the body's lack of response to parathyroid hormone instead of reduced production of the hormone.
Albright's hereditary osteodystrophy; Types 1A and 1B pseudohypoparathyroidism
The parathyroid glands help control calcium use and removal by the body. They do this by producing parathyroid hormone, or PTH. PTH helps control calcium, phosphorus, and vitamin D levels in the blood and bone.
Persons with pseudohypoparathyroidism produce the right amount of PTH. However, their body is "resistant" to its effect. This causes low levels of calcium and high levels of phosphate in the blood.
Pseudohypoparathyroidism is caused by abnormal genes. All forms of this condition are very rare.
Symptoms are related to low levels of calcium and include:
Persons with Albright's hereditary osteodystrophy may have the following symptoms:
Blood tests will be done to check calcium, phosphorus, and PTH levels. Urine tests may also be done.
Other tests may involve:
Calcium and vitamin D supplements are prescribed to maintain proper calcium levels. If blood phosphate levels remain high, a low-phosphorus diet or medicines called phosphate binders (such as calcium carbonate or calcium acetate) may be necessary.
Low blood calcium in pseudohypoparathyroidism is usually milder than in other forms of hypoparathyroidism.
Complications of low blood calcium may include:
Call your health care provider if you or your child has any symptoms of low calcium levels or pseudohypoparathyroidism.
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Bringhurst FR, Demay MB, Kronenberg HM. Disorders of mineral metabolism. In: Kronenberg HM, Schlomo M, Polansky KS, Larsen PR, eds. Williams Textbook of Endocrinology. 11th ed. St. Louis, Mo: WB Saunders; 2008:chap 27.
Doyle DA. Hypoparathyroidism. In: Kliegman RM, Stanton BM, St. Geme J, Schor N, Behrman RE, eds. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 565.