Burosumab treatment in a child with cutaneous skeletal hypophosphatemia syndrome: A case report.
case_report · Level V
Where this comes from
- Record sourced from PubMed, PMID 34660853.
- Also identified by DOI 10.1016/j.bonr.2021.101138 and PMC identifier 8502709.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Cutaneous skeletal hypophosphatemia syndrome (CSHS) is a rare disorder caused by somatic mosaicism for the gain of function <i>RAS</i> mutations . Affected patients have segmental epidermal nevi, dysplastic cortical bony lesions, and fibroblast growth factor-23 (FGF23)-mediated hypophosphatemic rickets. Herein, we describe a case of an Emirati girl with CSHS, whose hypophosphatemic rickets and osteomalcic pseudofractures and dysplastic bony lesions failed to recover due to poor adherence to treatment with oral phosphate supplements and alfacalcidol (conventional treatment). Treatment with burosumab, a fully human immunoglobulin G1 monoclonal antibody against FGF23 for 12 months, led to normalization of serum inorganic phosphate and alkaline phosphatase levels, radiographic healing of rickets, partial healing of pseudofractures, improvement in 6-minute walk test, and the physical scale of the Pediatric Quality of Life Inventory. We conclude that burosumab is effective in treatment of CSHS, however results of the ongoing phase 2 trial in adults (NCT02304367) are awaited.