BACKGROUND: Hereditary vitamin D-resistant rickets (HVDRR) is a rare genetic disorder caused by mutations in the vitamin D receptor (VDR) gene, which result in end-organ resistance to 1,25-(OH)2D3. PATIENTs with HVDRR are mostly treated using i.v. calcium therapy with a central catheter. However, central catheter-related complications have been reported. PATIENT: The patient was a 3-year-old boy presenting with waddling gait and alopecia. He had hypocalcemia [8 mg/dl (2 mmol/l)], hyperparathyroidism (1,232 ng/l), and elevated 1,25-(OH)2D3 levels (>250 pmol/l). DNA sequence analyses of the VDR gene showed a homozygous C-T transition at codon 152, resulting in a non-sense mutation in exon 5. INTERVENTIONS AND OUTCOMES: The patient was initially treated with calcitriol (80 ng/kg/day) and high-dose oral calcium (150 mg/kg/day) for one year. At the end of the first year, intermittent (5 days per month) i.v. calcium therapy without a central catheter was initiated because of insufficient clinical and radiological improvement. After 2 years of intermittent i.v. calcium therapy, there was a clear improvement based on clinical progress and on X-ray and biochemical findings. No peripheral complications were reported either. CONCLUSION: HVDRR with a non-sense mutation in the ligand-binding domain and alopecia was successfully treated with intermittent i.v. calcium without a central catheter.
BACKGROUND: Hereditary vitamin D-resistant rickets (HVDRR) is a rare genetic disorder caused by mutations in the vitamin D receptor (VDR) gene, which result in end-organ resistance to 1,25-(OH)2D3. PATIENTs with HVDRR are mostly treated using i.v. calcium therapy with a central catheter. However, central catheter-related complications have been reported. PATIENT: The patient was a 3-year-old boy presenting with waddling gait and alopecia. He had hypocalcemia [8 mg/dl (2 mmol/l)], hyperparathyroidism (1,232 ng/l), and elevated 1,25-(OH)2D3 levels (>250 pmol/l). DNA sequence analyses of the VDR gene showed a homozygous C-T transition at codon 152, resulting in a non-sense mutation in exon 5. INTERVENTIONS AND OUTCOMES: The patient was initially treated with calcitriol (80 ng/kg/day) and high-dose oral calcium (150 mg/kg/day) for one year. At the end of the first year, intermittent (5 days per month) i.v. calcium therapy without a central catheter was initiated because of insufficient clinical and radiological improvement. After 2 years of intermittent i.v. calcium therapy, there was a clear improvement based on clinical progress and on X-ray and biochemical findings. No peripheral complications were reported either. CONCLUSION: HVDRR with a non-sense mutation in the ligand-binding domain and alopecia was successfully treated with intermittent i.v. calcium without a central catheter.