Paediatr Child Health
A 3-month-old term nonconsanguineous female infant was found to have a bulging anterior fontanelle at her 2-month visit. Two weeks later upon presenting to the emergency room with a viral illness, investigations showed hypophosphatemia 0.49 mmol/L (1.3 to 2.6 mmol/L), normocalcemia 2.65 mmol/L (2.24 to 2.74 mmol/L), and parathyroid hormone (PTH) <0.3 pmol/L (1.6 to 6.9 pmol/L). Workup for hypophosphatemia including head and renal ultrasounds was unremarkable. X-rays showed flaring of metaphyses in femurs, tibiae, and fibulae, and she was started on phosphate (3 mmol 4 times a day) and vitamin D (Calcitriol equivalent to 1,000 IU daily) for presumed congenital rickets.