This protocol addresses rickets arising from a defect in the NaPi2a sodium-dependent phosphate transporter, encoded by SLC34A1, located in the proximal renal tubules. The transporter defect results in hypophosphatemia accompanied by suppressed FGF23 levels and excessive 1,25(OH)₂D levels. Nephrocalcinosis is a recognised feature of this presentation.
Management centres on oral phosphate supplementation — the specific formulation approach and the rationale for avoiding active vitamin D in this setting are detailed in the full protocol.Full regimen, selection criteria, and monitoring available via the structured protocol below.
Rapid normalization of serum phosphate levels, normalization of calcium and vitamin D metabolism parameters, and improved weight gain.
DOI: 10.1007/s00467-022-05505-5
This disease is also due to a defect in a sodium-dependent phosphate transporter located in the proximal tubules (in this case NaPi2a encoded by SLC34A1) resulting in hypophosphatemia, suppressed FGF23 levels and excessive 1,25(OH)2D levels. Therefore, treatment should be as described for HHRH patients.
A retrospective observational study of phosphate supplementation in 6 of 16 children with biallelic SLC34A1 mutations showed rapid normalization of serum phosphate levels and parameters of calcium/vitamin D metabolism which was associated with improved weight gain.
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