Diagnosis and treatment in Australia
How HPP is identified, which tests matter, where to be referred, and the honest position on treatment access for Australians.
Your blood test showed a low ALP. What now?
Alkaline phosphatase is a routine item on standard blood panels, so most people find out about a low result by accident. It is easy to overlook, because results below the normal range attract far less attention than results above it.
First, don't panic. A single low ALP has many explanations that are much more common than HPP, and most people with one do not have it.
Second, don't ignore it either. A low ALP that stays low, especially alongside bone pain, unexplained fractures or early tooth loss, is the single most useful clue there is.
What to ask your GP
- Can we repeat the ALP to see whether it is consistently low?
- Is my result being compared to the range for my age and sex? Children and teenagers normally have much higher ALP than adults, so an adult range can hide a real problem.
- Could anything else be lowering it, such as medication, thyroid, coeliac disease, zinc or magnesium?
- Given my symptoms, should we test vitamin B6 and urine phosphoethanolamine?
One thing that trips up the test
Blood collected into tubes containing EDTA or oxalate anticoagulant will show a falsely low ALP, because those additives strip out the minerals the enzyme needs to work.
If ALP is being measured to investigate HPP, it is worth the collector knowing that. A falsely low result sends people down the wrong path; so does dismissing a genuinely low one as a lab error.
Other causes of low ALP
Worth excluding before concluding anything:
- Bisphosphonates and denosumab
- Underactive thyroid or parathyroid
- Coeliac disease and malabsorption
- Zinc, magnesium or vitamin C deficiency
- Wilson's disease; multiple myeloma
- Serious illness, major surgery or recent chemotherapy
- High-dose steroids
Which tests actually matter
HPP is a clinical diagnosis supported by biochemistry. Genetic testing confirms it, but is not always required, and a negative genetic result does not rule it out.
| Test | What it shows in HPP | Notes |
|---|---|---|
| Serum alkaline phosphatase (ALP) | Persistently low for age and sex | The cornerstone. Order total ALP, not bone-specific ALP. Repeat it, because one reading is not enough. Avoid EDTA/oxalate tubes. |
| Vitamin B6 (pyridoxal 5′-phosphate) | Elevated | The most sensitive marker. Must be measured off vitamin B6 supplements, which will invalidate the result. |
| Urine phosphoethanolamine (PEA) | Elevated | Supportive, not conclusive. Can be normal in mild HPP and raised in unaffected relatives. |
| Calcium and phosphate | Normal or high | This is what separates HPP from vitamin D deficiency rickets, where both are low. |
| Parathyroid hormone | Suppressed or low-normal | Helps distinguish HPP from other causes of bone softening. |
| Vitamin D | Usually normal | Important to check, both to exclude deficiency rickets and to avoid over-supplementing later. |
| X-rays | Characteristic changes | In children, tongue-shaped lucencies extending from the growth plates. In adults, foot stress fractures and thigh-bone pseudofractures. |
| ALPL gene sequencing | Pathogenic variant(s) | Confirms the diagnosis and informs family testing. Detects the great majority, but not all, cases. |
Bone density scans are hard to interpret in HPP
DXA results can be misleading, because mineralisation is patchy and body proportions are often affected. A DXA number on its own should not drive decisions here.
The Australian referral pathway
There is no dedicated HPP clinic anywhere in Australia. Care happens within existing bone and mineral services, so knowing exactly what to ask for makes a real difference.
Your GP
The entry point for almost everyone. Bring the pattern, not just one result: repeated low ALP, plus your symptoms and family history.
Confirmatory bloods
Repeat ALP, vitamin B6, urine PEA, calcium, phosphate, PTH and vitamin D. Imaging where there is a fracture history.
Specialist referral
Children: paediatric endocrinology or a bone health service at a children's hospital. Adults: a bone and mineral or metabolic bone clinic at a major public hospital. Most need a GP referral and have a waiting list.
Clinical genetics
For ALPL testing and family counselling, usually via a state clinical genetics service on specialist referral.
Your ongoing team
HPP care is shared, typically between a bone specialist, a dentist familiar with the condition, a physiotherapist, a pain specialist where needed, and your GP holding it together.
Testing the ALPL gene in Australia
Genetic testing can confirm an HPP diagnosis, clarify which form someone has, and let relatives be tested for the same change. It is normally arranged by a specialist or a clinical genetics service rather than ordered directly.
Access in Australia is not straightforward. No Australian laboratory publicly advertises a dedicated HPP or ALPL test. In practice, testing is arranged through a public clinical genetics service, sometimes as part of a broader bone-disorder gene panel, and sometimes sent overseas.
Medicare rarely covers it. The main Medicare item for genetic sequencing is restricted to children aged ten or under who have particular features that most people with HPP do not have. Testing is therefore usually funded by the public hospital genetics service, or paid for privately.
Ask your specialist directly: “How would ALPL testing be arranged and funded for me here?” The answer varies by state and by hospital.
What a genetic result can and can't tell you
It can confirm the diagnosis
Finding a known disease-causing change in ALPL settles the question.
It can help your family
Once the specific change is known, relatives can be tested for that one change, which is far simpler and cheaper.
It cannot predict severity
People with identical changes can be affected very differently. The result does not tell you how life will go.
A negative result does not rule HPP out
Not every causative change is detectable by current testing. If the biochemistry and symptoms fit, HPP remains on the table.
What treatment exists
Enzyme replacement therapy
Asfotase alfa (brand name Strensiq) is the only disease-specific treatment for HPP. It is a manufactured version of the missing enzyme, engineered to travel to bone and do the job the body's own enzyme cannot.
It is given by injection under the skin, several times a week, and is continued long term. In babies and children with severe disease the results have been substantial: markedly better survival, improved breathing, and bones that mineralise where previously they did not.
It is not a cure and it does not suit everyone. Injection-site reactions are common; allergic reactions and mineral deposits in the eyes and kidneys have been reported, so people on treatment are monitored regularly. International guidance recommends against it for dental-only HPP.
Everything else that helps
Pain management
Anti-inflammatories are generally first choice. Opioids tend to be of limited benefit in HPP and carry real downsides.
Dental care
Keeping teeth in place matters for speech and nutrition, not just appearance. Regular review with a dentist who understands HPP.
Physiotherapy
Supervised, varied, mild-to-moderate activity is recommended at every age, adjusted to what your body tolerates.
Orthopaedic and orthotic support
Custom orthotics for foot and leg alignment; fracture management that expects slower healing.
Vitamin B6 for seizures
In severely affected babies, pyridoxine can control the seizures caused by HPP.
Occupational therapy
Practical adjustments at home, school and work that reduce load and conserve energy.
Who can actually get funded treatment in Australia
This is the single most important thing on this page, and the part most often misunderstood.
Asfotase alfa is registered with the Therapeutic Goods Administration, so it is a legal medicine in Australia. But registration and funding are different things.
It is not on the Pharmaceutical Benefits Scheme. It is funded instead through the Commonwealth's Life Saving Drugs Program, and that program covers one narrow group: people whose HPP began before six months of age, the perinatal and infantile forms.
Applicants must also have a documented history of at least one of: breathing failure needing ventilation, vitamin B6-dependent seizures, or a rachitic chest deformity. Applications are made by a treating specialist, not by patients, and are renewed annually.
What this means in practice
- Babies with perinatal or infantile HPP can access funded treatment, at no cost to the family, if they meet the criteria.
- Children whose HPP began after six months, the childhood or juvenile form, are not covered. This surprises many families who assume “paediatric” means all children.
- Adults with HPP have no subsidised pathway to enzyme replacement therapy in Australia.
If you are outside the funded group, talk to your specialist about what options exist in your state or through research studies. Do not assume there is nothing, but equally do not assume access is available.
Funding arrangements change. This reflects the position as at August 2026, and a Commonwealth review of this listing is due during the second half of 2026. Always confirm the current position with your specialist or the Department of Health, Disability and Ageing.
Treatments to discuss carefully
Because HPP is so often mistaken for osteoporosis, people are sometimes started on medicines that may make the underlying problem worse.
Bisphosphonates and denosumab
These common osteoporosis medicines are generally avoided in HPP, and international guidance lists them as contraindicated. Bisphosphonates are chemically similar to the very substance that accumulates in HPP and blocks bone from hardening, so they can worsen the underlying defect.
The evidence is strongest for people with changes in both copies of the gene; for those with a single change the picture is less settled. If you have HPP and osteoporosis medication has been suggested, that is a conversation to have with a metabolic bone specialist before starting.
Teriparatide
Sometimes used off-label in adults with HPP, supported only by individual case reports rather than trials. Not standard care, not suitable for children, and a specialist decision.
Vitamin D and calcium supplements
HPP is not treated like ordinary rickets. Routine supplementation where calcium is already normal risks pushing blood calcium too high and depositing calcium in the kidneys. Supplement only where a genuine deficiency has been shown.
When to think of HPP
A short prompt for GPs, dentists, rheumatologists, endocrinologists and paediatricians.
Persistently low ALP
Age- and sex-adjusted, on at least two occasions, with other causes excluded. Note that antiresorptives themselves lower ALP.
Premature tooth loss
Primary teeth lost before age five with roots intact; or adult teeth lost without periodontal disease.
Atypical fractures
Recurrent metatarsal stress fractures, femoral pseudofractures, or non-union, particularly with normal or high calcium and phosphate.
Two practical points
Paediatric reference ranges are essential. Reading a child's ALP against an adult range is a well-recognised cause of missed diagnosis, because healthy children normally run much higher.
Keep it proportionate. HPP is rare, and the large majority of patients with a suppressed ALP, including those on bisphosphonates, do not have it. The aim is to consider it, not to over-diagnose it.
Clinician resources
Soft Bones USA's Physician's Guide to HPP is a useful clinical overview, with further material on their Clinician Education page.
Reviewed August 2026. General information only, drawn from international clinical literature and Australian government sources. Not medical advice, and not yet clinician-reviewed on behalf of Soft Bones Australia.