X-linked Hypophosphatemia (XLH)

Introduction to X-Linked Hypophosphatemia (XLH)

X-linked hypophosphatemia (XLH) is a rare genetic disorder caused by a mutation in the PHEX gene located on the X chromosome. It is a genetic disorder that affects the way the body handles phosphorus and calcium, leading to a wide range of symptoms that may vary in severity, including rickets (softening of the bones), bowed legs, bone pain and stiffness, dental problems, and short height. XLH is estimated to affect 1 out of 20,000–40,000 persons worldwide.

What Causes X-Linked Hypophosphatemia?

XLH is caused by a mutation in the PHEX gene, located on the X chromosome. The PHEX gene is responsible for regulating the enzyme called fibroblast growth factor 23 (FGF23). FGF23 is responsible for controlling the balance of phosphate and calcium in the body, and a mutation in the PHEX gene leads to an overproduction of FGF23, leading to abnormal levels of phosphate and calcium.

Symptoms of X-Linked Hypophosphatemia

Symptoms of XLH can vary in severity and may include:

  • Rickets (softening of the bones)
  • Bowed legs & bone pain & stiffness
  • Dental Problems
  • Short stature
  • Limb pain
  • Clumsiness & poor coordination
  • Frequent fractures & lower bone mineral density
  • Anemia
  • Kidney stones

Diagnosis, Treatment & Management of X-Linked Hypophosphatemia

Diagnosis of XLH is based on a medical history, physical examination, blood and urine tests, genetic testing, and radiological studies. Treatment is aimed at managing symptoms, and may include the use of phosphate supplements, Vitamin D supplements, bisphosphonates, and orthopedic surgery.

Management of XLH is based on symptomatic relief and prevention of long-term complications, and may include regular medical care, physical activity, dietary modifications, and pharmacologic treatments as necessary. In addition, regular monitoring of phosphate levels and bone mineral density is recommended to monitor and prevent potential complications.