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What is Hypophosphatasia?

Hypophosphatasia is a rare metabolic bone disorder characterized by decreased tissue nonspecific alkaline phosphatase and defective bone mineralization.


Hypophosphatasia is a rare metabolic bone disorder characterized by decreased tissue nonspecific alkaline phosphatase and defective bone mineralization.
Acknowledgement of Hypophosphatasia has not been added yet.
Synonyms for Hypophosphatasia has not been added yet.
Researchers have concluded that Hypophosphatasia is caused by mutations in the ALPL gene ( This gene provides instructions for creating an enzyme called alkaline phosphatase, which plays an essential role in mineralization of bones in the body. When the genetic code is mutated, the abnormal version of alkaline phosphatase that is produced cannot participate effectively in the mineralization process ( As a result the substances that are normally processed by this enzyme will build up in the body (e.g. phosphoethanolamine, pyridoxal 5’-phosphate, and inorganic pyrophosphate). It is this accumulation of substances that causes the defective mineralization of bones ( Hypophosphatasia is inherited in an autosomal recessive pattern, which means that two copies of the gene in each cell are altered. Usually, each of the parents will carry a copy of the mutated gene but will not exhibit the disease symptoms themselves (
Hypophosphatasia is an extremely variable disease because five different clinical forms have been identified based upon the age of onset ( These are the perinatal, infantile, childhood, adult, and odontohypophosphatasia forms. The severity of the symptoms depend primarily on the amount of alkaline phosphate activity in the body, with a lower enzyme level correlating to a more serious case ( Since Hypophosphatasia is so variable, not all patients will have the major symptoms mentioned below ( When the disease occurs before childbirth (prenatal benign hypophosphatasia), the baby’s skeleton does not form properly in the mother’s womb. As a result, these infants often have short, bowed arms and legs and underdeveloped ribs ( Unfortunately, some cases end in stillbirth, while other infants do not make it more than a few days due to respiratory failure. However, it is not uncommon for the skeletal abnormalities to improve as the child grows ( Although patients suffering from Infantile hypophosphatasia may not show any symptoms at birth, they can present themselves within the first six months. A common symptom is the failure to gain weight and grow at the expected rate ( Young children with the disease often have high levels of calcium in the blood (hypercalcemia), which can lead to frequent vomiting and kidney problems. These symptoms can be life-threatening in certain cases ( The mildest form of hypophosphatasia is called odontohypophosphatasia. The disease only affects the teeth, and patients do not exhibit any of the other severe symptoms.
Name Description
Bone pain Bone pain
Early loss of deciduous teeth Early loss of deciduous (baby) teeth
Bone malformations Bone malformations
A diagnosis of hypophosphatasia is based upon characteristic signs and symptoms, a thorough clinical evaluation, a detailed patient history, and a variety of laboratory tests including x-ray studies ( Unfortunately, many patients face a huge delay in diagnosis because some physicians are not familiar with this rare disease. When the disease is suspected based on physical symptoms, the patient may be tested to measure the activity of alkaline phosphatase in blood ( This is the enzyme that plays an important role in the mineralization of bones. A diagnosis of the disease can be further proven by measuring the serum level of vitamin B6, since the concentration of this molecule will be elevated in patients suffering from hypophosphatasia ( Finally, molecular genetic testing can be used to specifically investigate the ALPL gene which is a known cause of the disease. However, this process is very expensive and can only be performed in certain medical centres.
Diagnostic tests of Hypophosphatasia has not been added yet
Currently, here is no cure for hypophosphatasia and no proven medical therapy, so treatment is mainly directed towards preventing or managing the complications or symptoms ( Although there are no cures officially approved by the Food and Drug Administration (FDA) for the treatment of hypophosphatasia, there are some medications being investigated. For example, it has been revealed that dietary phosphate restriction could be helpful in the management of hypophosphatasia ( Since hypophosphatasia mainly affects the skeletal system, non-steroidal anti-inflammatory drugs (NSAIDs) may be given to ease joint pain. Furthermore, regular dental care is important to prolong the lifespan of teeth ( For patients who suffer from frequent fractures of long bones in the arms and legs, a procedure called “rodding” can help to prevent further damage. An orthopedic surgeon will place a metal rod through the center opening of a bone to reinforce it (
Depending on the time of diagnosis, the prognosis of the disease can be variable for different patients. Severe cases of hypophosphatasia in infants are often lethal. Many children die within the first few days from respiratory complications due to chest deformations. However, life expectancy usually is not affected in adult cases of the disease and odontohypophosphatasia (
Tips or Suggestions of Hypophosphatasia has not been added yet.
References of Hypophosphatasia has not been added yet.
Tampa teen creates app to connect people fighting rare diseases Created by shannon.ashoori
Last updated 26 May 2020, 06:22 AM

Posted by shannon.ashoori
26 May 2020, 06:22 AM

Check out this article about Claire Barrow, a 13-year old girl living with hypophosphatasia. Claire created a social media app for rare disease communities called “Rare Guru”. Rare Guru allows individuals with rare diseases to connect with others with the same condition.

648+1G>A Hypophosphatasia Created by Iisaakei
Last updated 28 Aug 2015, 05:57 PM

Posted by hppbone
28 Aug 2015, 05:57 PM

HI LISAAKEI I have two different mutations but you can check your mutations out on this link. Are you on facebook? there is a support page for hypophosphatasia people.. I'm Sue and I have HPP too

Posted by Iisaakei
29 Jun 2015, 07:05 PM

Anyone out there have this ALPL gene mutation?

Welcome! Created by Eric
Last updated 12 Oct 2008, 10:59 PM

Posted by Eric
12 Oct 2008, 10:59 PM

Welcome to the Hypophosphatasia RareShare Community. Feel free to post your questions or new discussion topics about this disorder on this forum. For those that haven’t yet joined this community, you will need to do so in order to post new threads or reply to current posts. It’s free and easy to signup. If you have any questions about this community or RareShare in general, please feel free to email me. You can find my email address in my profile, under the “About Me” section. -Eric

Community External News Link
Title Date Link
My Constant Insomnia Turned Out to Be a Symptom of a Rare Disorder Called Hypophosphatasia 07/29/2020
Community Resources
Title Description Date Link
Canadian Hypophosphatasia Contact

Canadian website about Hypophosphatasia.


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Born with perinatal & infantile gene mutations of the rare disease Hypophosphatasia. I have had over 96+ fractures, 29 long bones rodings and 1 hip replacement and 4 level cervical rod and plate &...
My daughter Abigail was recently diagnosed with hypophosphatasia. I would like to get to know other families. Right now I am feeling like we are alone. I would like to hear your stories.

My first episode was in 2008. I was misdiagnosed with anaphylaxsis up until fall 2011. I started IVIG treatment in February 2012. Since then, I have had no episodes. I am now on bi-weekly...

Diagnosed at 12
dad of alex
hello to all of you, my name is Lorraine I'm 24, from this website to interact and meet people who have an interest in the area of health. From 2 years old I found a malformation in my lower...
My son is 5 months old with Hypophosphatasia currently participating in an experimental study.
i have Hypophosphatasia. i'm married with 3 children ages 3,5,14.
i had a beautiful baby girl 24 years ago, she died at just 6 days old, i have since gone on to have two healthy children but still dont really know much about hypophosphatasia
my husband and i have just lost our baby boy at 15 weeks to this dreadful disease



we had never even heard of the disease until our baby was diagnosed at not even a day old



I have Hypophasphatasia, although my doctor feels that a low count is nothing to be concerned about. I disagree. My counts get lower every year. My aunt also has it & is being treated in VA. For...
I am a servant of Jesus Christ, a mother, & a grandmother with multiple inherited disabilities, the full-force effects of which have all come upon me in just the last few years. I'm learning to...

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648+1G>A Hypophosphatasia

Created by Iisaakei | Last updated 28 Aug 2015, 05:57 PM


Created by Eric | Last updated 12 Oct 2008, 10:59 PM


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