Hormone and bone diseases
An inherited phosphate disease. The kidneys lose too much phosphate in the urine. Phosphate in the blood falls, the bones become soft and the legs may bow.
Not part of the panel of Türkiye's National Newborn Screening Programme (heel-prick test). Source
This page is translated from the Turkish original.
This disease is followed through the “Hormone and bone diseases” group.
A change in the PHEX gene leads to an increase in a protein called FGF23. This protein reduces how much phosphate the kidneys take back and how much the gut absorbs. Phosphate is needed for bones and teeth. When phosphate is low, children get rickets and adults get softening of the bones.
Symptoms can be very different even within the same family. Some people only have low blood phosphate.
Bowed legs and short stature are examined with X-rays. In the blood, phosphate is low while calcium and vitamin D are normal. The phosphate loss through the kidneys is measured. A genetic test shows the exact cause.
There is an approved treatment specific to the disease. This treatment blocks the effect of FGF23 and can be used in both children and adults. The older approach is phosphate and active vitamin D supplements. These supplements need regular blood and urine checks. Dental care, orthopedic follow-up and surgery if needed are provided. Early treatment can reduce bone problems. The doctor who follows the disease decides which treatment is suitable.
The disease is passed on through the X chromosome. Girls and boys can be affected in a similar way. An affected mother passes it to each child with a 50 percent chance. An affected father passes it to all his daughters but not to his sons. Genetic counselling guides the family.
Source: MedlinePlus Genetics: X-linked hypophosphatemia · NORD: Familial Hypophosphatemia
These facts are taken from Orphanet and MedlinePlus records (last checked: October 7, 2026). Frequency values are approximate ranges.
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
Doktorclub does not diagnose, recommend treatments or refer you to hospitals or doctors. These pages are meant to help you talk with your doctor.
TürkiyeDiagnosis and screening
At Marmara University, 50 patients with inherited low phosphate levels were studied genetically.
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.
Questions you can ask your doctor
ClinicalTrials.gov lists 3 active interventional studies for this disease. 3 are recruiting now; none has a site in Türkiye. Last checked: October 7, 2026.
Selected records (studies with a site in Türkiye first):
Middle stage: the effect is being tested in a small group · Phase 1 / Phase 2 · investigational (experimental)RecruitingNCT06525636
Early stage: safety and dose are being tested · Early phase 1 · investigational (experimental)RecruitingNCT03771105
Non-drug study (device, procedure, care, etc.)RecruitingNCT06921720
See all studies on ClinicalTrials.gov · Joining clinical trials
GlobalResearch and clinical trials
The trial included 63 adults from 16 countries.
TürkiyeResearch and clinical trials
At Bursa Uludağ University, the move of 29 young people with CAH (congenital adrenal hyperplasia) from pediatric to adult doctors was studied.
GlobalResearch and clinical trials
Once-weekly growth hormone was tested in girls with Turner syndrome.
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:89936
No separate ICD-11 code; WHO classifies this disease under: 5C63.22
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.