ESPE Abstracts

Background: Patients with vitD resistant rickets (VDRR) due to vitD receptor (VDR) mutations have extreme rickets along with alopesia, severe hypocalcemia, hypophosfatemia secondary to hyperparathroidism and elevated 1,25(OH)2vitD. Although there is no standard therapy for this patients, long-term or intermittanat i.v. or high dose oral calcium suplementations are recommended to correct the hypocalcemia and secondary hyperparathyroidism. Preliminary studies revealed that calcimimetics may be safe and effective therapeutic choise in children with secondary hyperparathyroidism.

Objective and hypotheses: To observe the efficacy of cinacalcet on the normalization of secondary.

Method: Two siblings, one at the age of 2 years – 6 months and the other at 4 months old were admitted to the hospital with severe hypocalcemia. Radiological and biochemical findings showed advanced features of rickets. Analysis of VDR gene identified a homozygot stop-codon mutation in exon 4 at nucleotide position 148 (c.148C>T) from both siblings. They were treated with high dose calcitriol and intermittant i.v. calcium infusions. Secondary hyperparathroidism was normalized temporarly, but not improve completly. We started cinacalcet (0.25 mg/kg) once a day along with high dose oral calcium and calcitriol, after 3 months biochemical and radiologic findings were return to normal status.

Conclusion: We observed that cinacalcet is succesfull to normalize of secondary hyperparathyroidism and hypophosphatemia and to restore bone findings.