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J Pediatr Genet 2023; 12(04): 308-311
DOI: 10.1055/s-0041-1728746
Case-Based Review

A De Novo Mosaic PHEX Variant Causing Sporadic X-Linked Hypophosphatemic Rickets in a 2-Year-Old Girl

Kok-Siong Poon 
1   Department of Laboratory Medicine, National University Hospital, Singapore
,
Karen Mei-Ling Tan 
1   Department of Laboratory Medicine, National University Hospital, Singapore
,
Margaret Zacharin
2   Department of Hormone Research, Murdoch Children's Research Institute, Melbourne, Australia
3   Department of Paediatrics, University of Melbourne, Victoria, Australia
4   Department of Endocrinology & Diabetes, The Royal Children's Hospital, Melbourne, Victoria, Australia
,
Cindy Wei-Li Ho 
5   Department of Paediatrics, Khoo Teck Puat - National University Children's Medical Institute, National University Health System, Singapore
6   Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
› Author Affiliations Funding This study was supported by NUHS Allied Health and Nursing Grant 2014 (Ref: NUHSRO/2015/046/AHN/03) awarded to Kok-Siong Poon.
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Abstract

Pathogenic variants in the PHEX gene are causative of X-linked hypophosphatemic rickets (XLH). We present a case of a 2-year-old girl with hypophosphatemic rickets with genu varum and short stature without any family history of XLH. Next generation sequencing of the PHEX gene identified a splice donor variant, NM_000444.6:c.1173 + 5G > A in intron 10. This variant had a mosaic pattern with only 22% of the sequence reads showing the variant allele and was not present in the girl's parents, both of whom had a normal phenotype. This is a sporadic case of a de novo mosaic splice-site variant in the PHEX gene.

Keywords

PHEX - X-linked hypophosphatemic rickets - mosaic


Publication History

Received: 08 January 2021

Accepted: 11 March 2021

Article published online:
01 June 2021

© 2021. Thieme. All rights reserved.

Georg Thieme Verlag KG
Rüdigerstraße 14, 70469 Stuttgart, Germany

 

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