X-linked hypophosphatemic rickets associated with respiratory failure.

We report a 5-year-old girl who presented to our emergency room with respiratory arrest and limb deformities and was subsequently diagnosed with X-linked hypophosphatemic rickets. On normalization of the serum phosphorus concentration, her respiratory distress resolved, illustrating that untreated X-linked hypophosphatemic rickets can lead to life-threatening respiratory distress.