Ann Pediatr Endocrinol Metab.  2014 Mar;19(1):36-41. 10.6065/apem.2014.19.1.36.

A novel de novo mutation within PHEX gene in a young girl with hypophosphatemic rickets and review of literature

• Cheon CK
• Lee HS
• Kim SY
• Kwak MJ
• Kim GH
• Yoo HW

• KMID: 1702662
• DOI: http://doi.org/10.6065/apem.2014.19.1.36

Abstract

X-linked hypophosphatemia (XLH) is the most common form of familial hypophosphatemic rickets and it is caused by loss-of-function mutations in the PHEX gene. Recently, a wide variety of PHEX gene defects in XLH have been revealed; these include missense mutations, nonsense mutations, splice site mutations, insertions, and deletions. Recently, we encountered a 2-year-9-month-old female with sporadic hypophosphatemic rickets. She underwent osteotomy, dental abscess was evident, and there was severe bowing of the legs. A low serum phosphorus level in combination with elevated serum alkaline phosphatase activity and normal serum calcium is suggestive of hypophosphatemic rickets. PHEX gene analysis revealed a splice acceptor site mutation, c.934-1G>T (IVS8-1G>T), at the intron8 and exon9 junction. To the best of our knowledge, this mutation is novel and has not been reported. The results of this study expand and improve our understanding of the clinical and molecular characteristics and the global pool of patients with sporadic hypophosphatemic rickets.

Keyword

Hunam PHEX protein; Mutation; Hypophospatemic rickets

MeSH Terms

Abscess
Alkaline Phosphatase
Calcium
Codon, Nonsense
Familial Hypophosphatemic Rickets
Female
Humans
Leg
Mutation, Missense
Osteotomy
Phosphorus
Rickets, Hypophosphatemic*
RNA Splice Sites
Alkaline Phosphatase
Calcium
Codon, Nonsense
Phosphorus
RNA Splice Sites

Figure

• 

  Fig. 1 (A) Initial radiological exam shows severe symmetric shortening and deformation of both legs. (B) At the 22-month follow-up, radiologic finding still shows widening of the proximal tibial metaphysis with medial bowing.

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  Fig. 2 Partial genomic DNA sequence of the PHEX gene of the patient: Novel splice site mutation, c.934-1G>T (IVS8-1G>T), in the PHEX gene

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