title: A Novel PHEX Gene Mutation in a Patient with Sporadic Hypophosphatemic Rickets.
abstract: Phosphate regulating gene with homologies to endopeptidases on the X-chromosome (PHEX) is a common cause of X-linked hypophosphatemic (XLH) rickets. Diverse PHEX gene mutations have been reported; however, gene mutations in sporadic rickets are less common than in XLH rickets. Herein, we describe a 50-year-old female patient with sporadic hypophosphatemic rickets harboring a novel splicing-site mutation in the PHEX gene (c.663+1G>A) at the exon 5-intron 5 boundary. The patient had recently suffered from right thigh pain and an aggravated waddling gait. She also presented with very short stature, generalized bone pain, and muscle weakness. Despite low serum phosphate levels, her phosphate reabsorption rate was lower than normal. Additionally, her 1,25-dihydroxyvitamin D3 concentration was lower than normal, although FGF23 level was normal. After treatment with alfacalcidol and elemental phosphate, her rachitic symptoms subsided, and callus formation was observed in the fracture site on the right femur.
authors.affiliation: Research Center for Endocrine and Metabolic Diseases, Department of Internal Medicine, Chungnam National University School of Medicine, Daejeon, Korea.
authors.forename: Yea Eun
authors.initials: YE
authors.lastname: Kang
authors.affiliation: Department of Internal Medicine, Kyungpook National University Hospital, Daegu, Korea.
authors.forename: Jun Hwa
authors.initials: JH
authors.lastname: Hong
authors.affiliation: Research Center for Endocrine and Metabolic Diseases, Department of Internal Medicine, Chungnam National University School of Medicine, Daejeon, Korea.
authors.forename: Jimin
authors.initials: J
authors.lastname: Kim
authors.affiliation: Research Center for Endocrine and Metabolic Diseases, Department of Internal Medicine, Chungnam National University School of Medicine, Daejeon, Korea.
authors.forename: Kyong Hye
authors.initials: KH
authors.lastname: Joung
authors.affiliation: Research Center for Endocrine and Metabolic Diseases, Department of Internal Medicine, Chungnam National University School of Medicine, Daejeon, Korea.
authors.forename: Hyun Jin
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Research Center for Endocrine and Metabolic Diseases, Department of Internal Medicine, Chungnam National University School of Medicine, Daejeon, Korea.
authors.forename: Bon Jeong
authors.initials: BJ
authors.lastname: Ku
authors.affiliation: Research Center for Endocrine and Metabolic Diseases, Department of Internal Medicine, Chungnam National University School of Medicine, Daejeon, Korea.
authors.forename: Koon Soon
authors.initials: KS
authors.lastname: Kim
keywords: Fibroblast growth factor 23; Phosphate regulating gene with homologies to endopeptidases on the X-chromosome; Rickets, hypophosphatemic