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Toshiyuki Yamamoto
Department School of Medicine(Tokyo Women's Medical University Hospital), School of Medicine Position Professor |
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| Article types | Case report |
| Language | English |
| Peer review | Peer reviewed |
| Title | A Novel PHEX Mutation in Japanese Patients with X-Linked Hypophosphatemic Rickets. |
| Journal | Formal name：Case reports in genetics Abbreviation：Case Rep Genet ISSN code：(2090-6544)2090-6552(Linking) |
| Domestic / Foregin | Foregin |
| Volume, Issue, Page | 2015,pp.301264 |
| Author and coauthor | Kawahara T, Watanabe H, Omae R, Yamamoto T, Inazu T |
| Publication date | 2015 |
| Summary | X-linked hypophosphatemic rickets (XLH) is a dominant inherited disorder characterized by renal phosphate wasting, aberrant vitamin D metabolism, and abnormal bone mineralization. Inactivating mutations in the gene encoding phosphate-regulating gene with homologies to endopeptidases on the X chromosome (PHEX) have been found to be associated with XLH. Here, we report a 16-year-old female patient affected by hypophosphatemic rickets. We evaluated her serum fibroblast growth factor 23 (FGF23) levels and conducted sequence analysis of the disease-associated genes of FGF23-related hypophosphatemic rickets: PHEX, FGF23, dentin matrix protein 1, and ectonucleotide pyrophosphatase/phosphodiesterase 1. She was diagnosed with XLH based on her clinical features and family history. Additionally, we observed elevated FGF23 levels and a novel PHEX exon 9 mutation (c.947G>T; p.Gly316Val) inherited from her father. Although bioinformatics showed that the mutation was neutral, Gly316 is perfectly conserved among humans, mice, and rats, and there were no mutations in other FGF23-related rickets genes, suggesting that in silico analysis is limited in determining mutation pathogenicity. In summary, we present a female patient and her father with XLH harboring a novel PHEX mutation that appears to be causative of disease. Measurement of FGF23 for hypophosphatemic patients is therefore useful for the diagnosis of FGF23-dependent hypophosphatemia. |
| DOI | 10.1155/2015/301264 |
| PMID | 25861491 |