No Diagnosis for years and then the wrong one - Hypophosphatasia

Rare Disease Day 2021 is coming up – we, SKC, want to do our part to generate more awareness for these diseases. This time for hypophosphatasia.

Fri, 2021 / 02 / 26

In the fifth part of our blog series for the Rare Disease Day 2021, we would like to introduce you to the disease hypophosphatasia (HPP). It is difficult to measure the prevalence of HPP but it is estimated that 1/100,000 people suffer from a severe course of the disease. HPP is caused by a genetic defect which leads to an insufficient or defective production of an enzyme called alkaline phosphatase. This enzyme plays an important role in bone formation.

People with HPP show a wide range of symptoms. These include bone fractures, skeletal and skull deformation (oxycephaly), severe pain, muscle weakness, tooth loss, tooth decay, kidney damage, fatigue, short stature, joint calcifications, pseudogout, pneumonia, inner restlessness, nervous nausea, and depressive moods. The latter symptoms are rather psychological and also result from the fact that social participation is less frequent and more limited due to HPP than without this genetic disease. Particularly, the bone fractures lead to dependence on crutches and wheelchairs. Petra also uses a wheelchair. In a video, she and her husband provide insights into a life with HPP.

Although HPP is a congenital disorder, it is not always apparent at birth. In some cases, it leads to death in early childhood; however, in other cases symptoms appear in a later stage of life. Due to the variety of symptoms, it is very difficult to find the right diagnosis (HPP). Additionally, the disease varies in severity between patients and can progress differently between patients, even if they are siblings. Gerald Brandt, chairman and spokesman of the Würzburg Working Group for Rare Diseases (WAKSE), reports "Many people who call me cry because they have not been taken seriously for decades." In his experience, many patients are sent to a psychologist at the end of a journey with many visits to medical specialists. It can be assumed that their condition will continuously worsen until death.

Thanks to such working groups, more and more attention is being drawn to rare diseases. A noteworthy initiative specifically for those affected by HPP is called "Looks like... But is HPP". This initiative was launched by Alexion, a pharmaceutical manufacturer conducting research on HPP, and HPP Deutschland e.V. and takes place annually. The name of this initiative points to the problem of finding the right diagnosis. Without correct diagnosis, adequate treatment is not possible. In the case of HPP, "adequate" does not mean "curative" - because curative therapies do not yet exist. Today, first drugs were already approved for HPP. But still, there is a great unmet need for further treatment methods.

In the spirit of a strong community of solidarity, the legislator has decided not to accept such fates and has implemented regulations to make it easier for pharmaceutical manufacturers to introduce innovative drugs for patients with rare diseases. However, easier conditions for market access are not enough. For further progress, researchers and the general population must gain attention for rare diseases. The upcoming Rare Disease Day is an excellent occasion to do just that.

Further information can be found here:

(1) General information about the disease can be found on the Orphanet website.

(2) A contact point for patients can be international or national associations like the HPP Deutschland e.V.

(3) The website Hypophosphatasie.net is a service of the HPP Deutschland e.V. and aims to inform about HPP.