Endocrinology and Metabolism  2014;29(2):195-201

doi:10.3803/EnM.2014.29.2.195

A Novel PHEX Gene Mutation in a Patient with Sporadic Hypophosphatemic Rickets.

Yea Eun KANG 1 ; Jun Hwa HONG ; Jimin KIM ; Kyong Hye JOUNG ; Hyun Jin KIM ; Bon Jeong KU ; Koon Soon KIM

Affiliations

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Keywords

Phosphate regulating gene with homologies to endopeptidases on the X-chromosome; Rickets, hypophosphatemic; Fibroblast growth factor 23

Country

Republic of Korea

Language

English

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.