Autosomal Dominant Hypophosphatemic Rickets: A Case Report

Autosomal dominant hypophosphatemic rickets (ADHR) is characterized by isolated renal phosphate wasting, hypophosphatemia, and inappropriately normal 1,25-dihydroxyvitamin D3 (calcitriol) levels. We present a 3 y old girl with short stature and metaphases dysplasia. Plasma phosphorus was low, with high levels of alkaline phosphatase and parathormone. She has great loss of phosphorus in urine. Amino acids, bicarbonate, serum 1,25-dihydroxyvitamin D3 showed normal levels. Skeletal x-ray revealed signs of rickets particularly in the wrist. The DNA study detected missense mutations R179Q in FGF23 gene. We started treatment with calcitriol and Joulie solution with recovered of her growth, increasing 10.5 cm in 13 months. Her varus knees normalized during this period. The rickets signs on the x-ray become better. No family history was found. FGF23 gene of parents were negative. The risk for next pregnancy is low because our case was a sporadic presentation.