A 14-year-old girl experienced painful fractures in her hip bones without any injury or fall. Doctors discovered she had a rare genetic condition called autosomal dominant hypophosphatemic rickets (ADHR), which affects how her body handles minerals needed for strong bones. This condition is caused by a change in a gene called FGF23 that she inherited. After surgery to fix the fractures and starting treatment with special minerals and vitamin D, her pain improved significantly. This case is important because the disease can be hard to diagnose and shows up differently in different people, sometimes not appearing until the teenage years.

The Quick Take

  • What they studied: A single case of a teenage girl who developed unexplained fractures in her hip bones and was found to have a rare genetic bone disease
  • Who participated: One 14-year-old female patient with no previous history of bone problems during childhood
  • Key finding: The patient had a new genetic mutation in the FGF23 gene that caused her body to lose too much phosphate (a mineral needed for bone strength), leading to weak bones and fractures without any trauma or injury
  • What it means for you: If you or someone you know has unexplained bone pain or fractures, especially in the hip area, doctors should consider testing for rare mineral metabolism disorders. This case shows that genetic bone diseases can appear suddenly in teenagers without warning signs in childhood.

The Research Details

This is a case report, which means doctors are describing what happened with one specific patient in detail. The 14-year-old girl came to the hospital complaining of lower back and hip pain that had been getting worse for about a year. Doctors performed blood tests, imaging scans (X-rays and other pictures of her bones), and genetic testing to figure out what was wrong.

The genetic testing was the key discovery. Scientists found that the girl had a new mutation (a change) in her FGF23 gene. This gene normally helps control how much phosphate (a mineral) her body keeps. When this gene doesn’t work right, phosphate leaks out through the kidneys, making bones weak and brittle.

After diagnosis, the girl had surgery to stabilize her hip fractures and started taking phosphate supplements and a special form of vitamin D called calcitriol. Doctors followed up with her over time to see how she improved.

Case reports are important for rare diseases because they help doctors recognize patterns they might otherwise miss. Since ADHR is very uncommon, many doctors have never seen it before. By sharing this detailed story, the doctors help other medical professionals know what to look for and how to test for this condition.

This is a single case report, so it describes one person’s experience rather than testing a treatment on many people. While case reports are valuable for rare diseases, they cannot prove that a treatment works for everyone. The strength of this report is that it includes genetic testing, which confirms the diagnosis with certainty. The doctors also followed the patient over time to see if treatment helped, which makes the findings more reliable.

What the Results Show

The patient had bilateral sacral insufficiency fractures, which means both sides of her hip bones had stress fractures. These fractures happened without any trauma or accident—just from the weakness caused by her bone disease. Blood tests showed low levels of phosphate, which is the key finding in this condition.

Genetic testing revealed a de novo heterozygous variant in the FGF23 gene (specifically c.526C>T, p.Arg176Trp). The word ‘de novo’ means this was a brand new mutation that neither of her parents had—it happened spontaneously in her. This mutation disrupts the normal function of the FGF23 protein, which controls phosphate levels in the body.

What made this case unusual is that the girl had no signs of rickets (a childhood bone disease) during her younger years. The disease appeared suddenly in adolescence with fractures as the first major symptom. After surgery to fix the fractures and starting phosphate and vitamin D treatment, her pain improved significantly during follow-up visits.

The patient experienced progressive lower back and lumbar pain for approximately one year before diagnosis. The pain worsened with physical activities like walking and sitting. This delayed diagnosis is significant because it shows how this rare disease can be mistaken for other conditions. Once proper treatment began, the patient’s symptoms improved, suggesting that the combination of surgical repair and medical therapy was effective.

ADHR is known to have variable presentation—meaning it shows up differently in different people. Some patients develop symptoms in childhood with obvious rickets, while others don’t show symptoms until adolescence or adulthood. This case is notable because it appears to be the first reported case of an adolescent with ADHR presenting specifically with bilateral sacral insufficiency fractures. The genetic variant found in this patient (p.Arg176Trp) has very few cases reported in medical literature, making this case particularly valuable for understanding the disease’s full range of presentations.

This is a single case report, so the findings apply only to this one patient. We cannot conclude that all people with this genetic variant will have the same symptoms or that the same treatment will work for everyone. The case does not include a control group or comparison to other patients. Additionally, the follow-up period described in the report is not specified, so we don’t know how long the improvement lasted. More research with multiple patients would be needed to understand the full spectrum of this disease and the best treatment approaches.

The Bottom Line

If you have unexplained bone pain, fractures without injury, or a family history of bone disease, ask your doctor about testing for phosphate metabolism disorders. Treatment with phosphate supplements and vitamin D (calcitriol) appears effective based on this case. However, these recommendations are based on a single patient, so discuss with your doctor what’s right for your specific situation. (Confidence level: Low, based on single case report)

Teenagers and young adults with unexplained bone pain or fractures should be aware of this condition. Parents of children with growth problems or bone issues should know that genetic bone diseases can appear at different ages. Doctors who treat adolescents with musculoskeletal complaints should consider rare metabolic bone diseases in their differential diagnosis. People with a family history of rickets or bone disease should be especially alert.

In this case, the patient’s pain improved significantly after surgery and starting medical treatment, though the exact timeline for improvement is not specified in the report. Typically, bone healing takes several months, and the benefits of phosphate and vitamin D therapy may take weeks to months to become noticeable. Long-term management would likely be needed to prevent future fractures.

Want to Apply This Research?

  • Track daily bone pain levels (0-10 scale) and physical activities that trigger or worsen pain. Log phosphate supplement and vitamin D doses taken daily to ensure medication adherence.
  • Users with diagnosed ADHR or suspected bone disease should use the app to set reminders for taking phosphate and vitamin D supplements at the same time each day. They should also log activities that cause pain to identify patterns and share this information with their doctor.
  • Maintain a long-term log of pain levels, mobility improvements, and medication adherence. Track any new symptoms or changes in bone-related symptoms. Schedule regular check-ins with healthcare providers and record lab results (phosphate levels) when available to monitor disease progression and treatment effectiveness.

This case report describes one patient’s experience with a rare genetic bone disease. It is not medical advice and should not be used to diagnose or treat any condition. If you experience unexplained bone pain, fractures, or symptoms similar to those described, consult with a qualified healthcare provider for proper evaluation and diagnosis. Genetic testing and specialized blood work are necessary to diagnose this condition. Treatment decisions should be made in consultation with pediatric endocrinologists and orthopedic specialists. This information is educational only and does not replace professional medical guidance.