Signs and symptoms of XLH in adults

Jason, living with XLH

XLH may have been diagnosed during childhood, but the effects of an ongoing condition do not go away with time. Osteomalacia, the softening and weakening of bones, continues into adulthood. As a result, new symptoms may continue to appear or existing symptoms may worsen over time, which can limit the body’s movements. Understanding the progression of XLH and how the symptoms may affect daily life can help you or your loved one prepare for the challenges ahead.


Phosphate plays an important role in the development and growth of the bones. Low phosphate levels in the blood result in poor bone mineralization, which can impact bone health and function.


Unresolved Childhood Symptoms

Short stature is a symptom of XLH

Short stature

Osteomalacia is a symptom of XLH

Osteomalacia, which is the softening of bones due to poor mineralization

Bone and joint pain are symptoms of XLH

Bone and joint pain

Leg deformities are symptoms of XLH

Lower limb abnormalities like bowed legs and knock-knees

Irregular head shape is a symptom of XLH

Irregularities in the shape of the head, called craniosynostosis

Headaches may be from Chiari malformations due to XLH

Headaches may be due to a condition called Chiari malformation, where brain tissue may occupy space in part of the spinal canal

Osteomalacia is the underlying cause of pain, stiffness, and impaired physical mobility


New Symptoms

Mineralized tendons are a symptom of XLH

Enthesopathy or mineralization of tendons and ligaments surrounding the Achilles, knees, hips, and spine

Osteoarthritis is a symptom of XLH

Early onset of osteoarthritis or inflammation in the bones and joints

Fractures are a symptom of XLH

Fractures and pseudofractures (a kind of fracture where the bone thickens at the site of an injury but is not completely broken)

Hearing loss is a symptom of XLH

Hearing loss caused by poor mineralization of the small bones in the ears

As XLH progresses, these symptoms can cause pain and limit movement

Healthy bones support the normal development of muscles in the body. Low phosphate levels, which result in poor bone health, also have a related impact on the muscles’ ability to function properly.
Muscle weakness is a symptom of XLH

Muscle weakness

Muscle stiffness is a symptom of XLH

Muscle stiffness

Muscle pain is a symptom of XLH

Muscle pain

Weakened leg muscles can lead to a wobbly walk (waddling gait) and impaired physical ability
Like bones, the health of teeth also depends on the amount of phosphate in the body. Low phosphate levels can result in defects of the teeth.
Tooth abscesses are a symptom of XLH

Tooth abscesses

Periodontitis is a symptom of XLH


Dental problems can lead to pain, tooth infections, and eventual tooth loss