According to a story from Medical Xpress, a team of researchers affiliated with the University of Granada and the research organization CIBERFES have discovered a pair of new mutations linked to the rare bone disease hypophosphatasia after implementing a protocol designed to detect the illness. This disease is not easy to diagnose and can easily be confused with other bone disorders. As a result of their findings, the scientists believe that as many as 15,000 people in Spain could be living undiagnosed with hypophosphatasia.
About Hypophosphatasia (HPP)
Hypophosphatasia is a rare and potentially lethal disorder that affects bone metabolism. The timing of symptoms can range widely, with some patients dying before they are even born, whereas others don’t deal with symptoms until much later in life. The disease is linked to mutational defects of the TNSALP gene which codes for tissue non-specific alkaline phosphatase. When levels of TNSALP are low, bones do not form normally. Symptoms in younger patients include limb deformities, respiratory failure, soft bones, rickets, dental defects, delayed development, and muscle weakness. Symptoms in adult patients typically manifest as cartilage degeneration, loss of teeth, and arthritis. Treatment includes the drug asfotase alfa for younger patients; other treatment is mostly symptomatic and may include surgical intervention to correct deformities and dental care to compensate for tooth loss. To learn more about hypophosphatasia, click here.
The prediction of potentially 15,000 undiagnosed patients in Spain is based on findings from the study, as the authors determined that around half of the patients evaluated hadn’t been accurately diagnosed. Like with many other rare diseases, hypophosphatasia is routinely misdiagnosed. This is due to a combination of overall unfamiliarity with the disease and the fact that it can resemble more common problems such as osteoporosis. This can lead to the use of inappropriate therapies that can actually worsen the disease.
In the study levels of alkaline phosphatase (ALP) were evaluated in a massive sample of 78,590 people. The researchers found 1,907 adults that had ALP levels below the normal range. Of this group, 56 were selected as potential hypophosphatasia patients. From this sample, 16 agreed to continue their participation. This group tended to have few to no symptoms and had not previously been diagnosed.
The researchers concluded that it was likely that the majority of undiagnosed patients have mild disease with little to no symptoms. Check out the original study, published in Scientific Reports, here.