What is Pseudohypoparathyroidism?

Pseudohypoparathyroidism is an extremely rare condition that changes the way the body responds to the parathyroid hormone. It’s often compared to hypoparathyroidism, which means the body is not producing sufficient amounts of this hormone. Yet it’s very different because the body does have access to appropriate amounts of parathyroid hormone, but it fails to recognize or make use of it in the right way, leading to a collection of possible symptoms.

To make matters more confusing, pseudohypoparathyroidism comes in several types known as 1a, and 1b, and 2. 1a is often alternately named Albright’s hereditary osteodystrophy, and as the name implies this is an inherited condition. Researchers have discovered mode of inheritance is along autosomal dominant lines, which means it takes one parent to give one gene, so that it is expressed in the child. This means parents having a child with pseudohypoparathyroidism each have a 50% chance of having the condition, which they have probably noted given the symptoms.

The differences between pseudohypoparathyroidism 1a, 1b and 2 are not always fully clear. What is known is that failure to recognize parathyroid hormone in 1b primarily takes place in the kidneys, as contrasted to in 1a, where failure occurs through the body. In 2, symptoms are similar but some of the changes a person’s appearance present in 1a and 1b are not apparent.

With 1a and 1b pseudohypoparathyroidism, some of the most common symptoms include a presence of calcium under the skin in deposits, cataracts, feelings of numbness, rounded face, rounder body and tendency toward higher body weight. Other people experience seizures or muscle spasms called tetany, and there is high incidence of problems with teeth due to poor calcium. In addition to appearance, one of the most important diagnostic factors is low blood calcium and vitamin D levels with normal parathyroid hormone levels.

Untreated, there can be problems with pseudohypoparathyroidism. It can delay growth and failure to recognize parathyroid hormone can lead to low levels of thyroid hormone, which may further complicate development and even affect brain function. When the condition is diagnosed early, doctors usually address it with a variety of ways to get the body adequate vitamin D and calcium. These are through oral and occasionally through injected supplements.

Treatment early, which will probably continue for life, may be of most use in promoting healthy development. One concern with this condition is normal sexual development. This can be impaired if pseudohypoparathyroidism is not recognized early. Given its rarity and the fact that not all types are inherited via autosomal dominance, it may be possible to miss diagnosis. In particular, Type 2 is hard to diagnose at first due to its lack of physical features that might distinguish it.