GlobalResearch and clinical trials
Efzimfotase alfa in hypophosphatasia: positive in children, main goal not met in adolescents and adults
The phase 3 program included 196 patients from 22 countries.
Preliminary resultHypophosphatasia
Hormone and bone diseases
Hypophosphatasia (HPP)
An inherited bone and tooth disease. Not enough minerals settle into the bones and teeth. The bones become soft, and baby teeth may fall out early.
Not part of the panel of Türkiye's National Newborn Screening Programme (heel-prick test). Source
Orphanet has a guideline for emergency doctors for this disease (language: French). See on Orphanet
This page is translated from the Turkish original.
This disease is followed through the “Hormone and bone diseases” group.
Understanding the disease
This section has not yet been reviewed by a physician. It summarises patient information from sources such as MedlinePlus, Orphanet and the NHS in plain language. The disease can differ from person to person; talk to your doctor about diagnosis and treatment.
What happens in this disease?
A change in the ALPL gene weakens an enzyme called alkaline phosphatase. This enzyme helps calcium and phosphorus settle into the bone. When the enzyme is low, the bones and teeth do not harden enough. The disease can begin before birth or in adulthood.
Which symptoms can occur?
Symptoms range from very mild to severe. The most severe forms are seen in infancy.
- Early loss of baby teeth (one of the first signs in children)
- In a baby, short arms and legs and soft skull bones
- In a baby, feeding difficulties and poor weight gain
- Short stature, bowed or knock-kneed legs
- In adults, repeated fractures of the foot and thigh bones
- Bone, muscle and joint pain
- In the mildest form, only dental problems
How is it diagnosed?
A blood test finds alkaline phosphatase levels that are low for age. A substance related to vitamin B6 may be high in the blood. X-rays show the bone changes. A genetic test for the ALPL gene supports the diagnosis.
Treatment and care
For disease that begins in childhood, there is an approved enzyme treatment specific to the disease. Pain treatment, physiotherapy and dental care that starts early are important. Orthopedic support or surgery may be needed for fractures. Some medicines for bone loss can cause problems in this disease. The doctor who follows the disease decides which treatment is suitable.
For the family: inheritance and genetic counselling
The severe forms that begin early are passed on through recessive inheritance. For a couple who are both carriers, the chance of having an affected child is 1 in 4 in each pregnancy. Mild forms can be passed on in a recessive or dominant way. In dominant inheritance, a single changed gene is enough. Genetic counselling explains the situation in the family.
Source: MedlinePlus Genetics: Hypophosphatasia · NORD: Hypophosphatasia
Key facts
- How is it inherited?
- Autosomal dominant · Autosomal recessive
- When does it usually start?
- Any age
- Reliable sources
- MedlinePlus (for families) · Orphanet
These facts are taken from Orphanet and MedlinePlus records (last checked: October 7, 2026). Frequency values are approximate ranges.
You are not alone: patient associations in Türkiye
Non-profit patient and family organizations in Türkiye working on this disease or disease group. Links are for information; Doktorclub is not affiliated with these organizations and does not endorse them.
We could not find a patient association specific to this disease.
For all rare diseases: Nadir Hastalıklar Federasyonu
Support and help
- In an emergency in Türkiye, call 112.
- For psychological and social support, the ALO 183 Social Support Line (24/7, free from within Türkiye): alo183.aile.gov.tr
- For carers: Looking after yourself as a caregiver
- Preparing for a doctor visit · Collect your questions and symptom notes on one page, then print it and take it with you.
Doktorclub does not diagnose, recommend treatments or refer you to hospitals or doctors. These pages are meant to help you talk with your doctor.
News about Hypophosphatasia
TürkiyeDiagnosis and screening
2,243 children with low ALP levels screened in Ankara: hypophosphatasia found in 16
At Ankara Bilkent City Hospital, 2,243 children with low ALP levels were studied.
Peer-reviewed publicationHypophosphatasia
Clinical trials (ClinicalTrials.gov)
A clinical trial is a regulated study that tests whether a new treatment is safe and whether it works, in patients who volunteer. Most trials look for a certain age, genetic change and health condition. Taking part is voluntary.
This list is not a treatment recommendation. Treatments tested in phase 1–3 trials are investigational (experimental): their efficacy and safety have not yet been proven and they are not approved treatments. Taking part depends on each trial’s criteria and a physician’s assessment; the first step is to talk to the doctor who manages your care.
Questions you can ask your doctor
- Could this trial be suitable for us?
- If we take part, how would current treatment and check-ups be affected?
- Where does the trial take place, and how are travel and accommodation handled?
- What happens if we want to leave the trial?
ClinicalTrials.gov lists 4 active interventional studies for this disease. 1 is recruiting now; 3 have sites in Türkiye. Last checked: October 7, 2026.
Selected records (studies with a site in Türkiye first):
- Phase 3 Study of ALXN1850 Versus Placebo in Adolescent and Adult Participants With HPP Who Have Not Previously Been Treated With Asfotase Alfa
Late stage: the effect is being compared in a large group · Phase 3 · investigational (experimental)Active, not recruitingSite in TürkiyeNCT06079281
- Phase 3 Study of ALXN1850 in Treatment-Naïve Pediatric Participants With HPP
Late stage: the effect is being compared in a large group · Phase 3 · investigational (experimental)Active, not recruitingSite in TürkiyeNCT06079359
- Phase 3 Study of ALXN1850 in Pediatric Participants With HPP Previously Treated With Asfotase Alfa
Late stage: the effect is being compared in a large group · Phase 3 · investigational (experimental)Active, not recruitingSite in TürkiyeNCT06079372
- A Study to Assess Safety, Tolerability, Pharmacokinetics and Pharmacodynamics of ALE1 in Healthy Adults and Adults With Hypophosphatasia in Order to Identify Suitable Doses of ALE1
Middle stage: the effect is being tested in a small group · Phase 1 / Phase 2 · investigational (experimental)RecruitingNCT07179640
See all studies on ClinicalTrials.gov · Joining clinical trials
Hormone and bone diseases: other news
GlobalResearch and clinical trials
Garetosmab markedly reduced new bone formation in FOP in a phase 3 trial
The trial included 63 adults from 16 countries.
Peer-reviewed publicationFOP
TürkiyeResearch and clinical trials
Bursa study looks at how young people with CAH move from pediatric to adult doctors
At Bursa Uludağ University, the move of 29 young people with CAH (congenital adrenal hyperplasia) from pediatric to adult doctors was studied.
Peer-reviewed publicationCAH
GlobalResearch and clinical trials
Once-weekly growth hormone as effective as daily injections in Turner syndrome in a phase 3 trial
Once-weekly growth hormone was tested in girls with Turner syndrome.
Peer-reviewed publicationTurner
Medical codes (for talking with your doctor and finding sources)
These codes identify the disease in international classifications and databases. They can help when you talk with your doctor or look for reliable sources.
Orphanet code: ORPHA:436
No separate ICD-11 code; WHO classifies this disease under: 5C64.3
Codes checked against WHO ICD-11 and Orphanet on October 7, 2026.
This page provides general information and does not replace diagnosis or treatment. Talk to your doctor about symptoms, diagnosis and treatment.