RESUMEN
<p><b>OBJECTIVE</b>To investigate PHEX gene mutations in 2 patients with X-linked hypophosphatemic rickets (XLH) and their families and to clarify the genetic etiology.</p><p><b>METHODS</b>A retrospective analysis was performed for the clinical data of two patients with XLH. High-throughput sequencing was used to detect the PHEX gene, a pathogenic gene of XLH. PCR-Sanger sequencing was used to verify the distribution of mutations in families.</p><p><b>RESULTS</b>Both patients had novel mutations in the PHEX gene; one patient had a frameshift mutation, c.931dupC, which caused early termination of translation and produced the truncated protein p.Gln311Profs*13; the other patient had a splice site mutation, IVS14+1G>A, which caused the skipping of exon 15 and produced an incomplete amino acid chain. Their parents had normal gene phenotypes.</p><p><b>CONCLUSIONS</b>c.931dupC and IVS14+1G>A are two novel mutations of the PHEX gene and might be the new pathogenic mutations of XLH.</p>