New insights into the pathogenesis of inherited phosphate wasting disorders.

X-linked hypophosphatemic rickets and autosomal dominant hypophosphatemic rickets are inherited phosphate wasting disorders. X-linked hypophosphatemic rickets results from mutations in the PHEX gene, which codes for a protein that is a member of the neutral endopeptidase family. The gene that is responsible for autosomal dominant hypophosphatemic rickets has not yet been identified, however, positional cloning studies have narrowed the gene locus to chromosome 12p13. This review will focus on the pathogenesis of these disorders and how these disorders provide insight into normal phosphate homeostasis.