Rare PHEX intron variant causes complete and severe phenotype in a family with hypophosphatemic rickets: a case report
Author:
Aiello Francesca1ORCID, Pasquali Daniela2, Baronio Federico3, Cassio Alessandra3, Rossi Cesare3, Di Fraia Rosa2, Carotenuto Raffaela2, Digitale Lucia2, Festa Adalgisa1, Luongo Caterina1, Maltoni Giulio3, Schiano di Cola Roberta1, Del Giudice Emanuele Miraglia1, Grandone Anna1
Affiliation:
1. Department of Child, Woman, General and Specialized Surgery , University of Campania “Luigi Vanvitelli” , Naples , Italy 2. Endocrinology, Department of Advanced Medical and Surgical Sciences , University “Luigi Vanvitelli” , Naples , Italy 3. Department of Medical and Surgical Sciences-Unit of Paediatrics , University of Bologna , Bologna , Italy
Abstract
Abstract
Objectives
Lower limb deformities in children need careful orthopedic evaluation to distinguish physiological forms from pathological ones. X-linked hypophosphatemia (XLH) is a rare hereditary condition caused by PHEX gene mutations where tibial varum can be the first sign.
Case presentation
We report a family presenting with severe tibial varum, harbouring a rare PHEX intron mutation, c.1586+6T>C. This is the first clinical description available in literature for this variant. Despite the previous prediction of a mild phenotype in functional study, our patients showed important bone deformities, rickets and impaired growth since infancy followed by severe bone pain, hearing loss and reduced life quality in adulthood. Burosumab therapy improved biochemical and radiological findings in children and ameliorated quality of life in adults.
Conclusions
This case demonstrated c.1586+6T>C causes a severe XLH phenotype, responsive to Burosumab. Familial genetic screening, enlarged to intronic region analysis, when XLH is suspected, allows precocious diagnosis to start timely the appropriate treatment.
Publisher
Walter de Gruyter GmbH
Subject
Endocrinology,Endocrinology, Diabetes and Metabolism,Pediatrics, Perinatology and Child Health
Reference10 articles.
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