A Mild Presentation of X-Linked Hypophosphatemia Caused by a Non-Canonical Splice Site Variant in the PHEX Gene

X-linked hypophosphatemia (XLH) is a rare inherited disorder of renal phosphate wasting with a highly variable phenotype caused by loss-of-function variants in the PHEX gene. The diagnosis of individuals with mild phenotypes can be challenging and often delayed. Here, we describe a three-generation...

Descripción completa

Detalles Bibliográficos
Autores: Fraga Rodriguez, Gloria Maria|||0000-0002-7682-1396, Herreros García, Alba, Pybus, Marc|||0000-0002-6195-5738, Aza-Carmona, Miriam|||0000-0003-4448-9541, Pilco-Teran, Melissa, Furlano, Monica|||0000-0003-1025-3901, Garcia Borau, Maria José|||0000-0002-8223-8033, Torra Balcells, Roser|||0000-0001-8714-2332, Ars, Elisabet|||0000-0002-4118-4358
Tipo de recurso: artículo
Fecha de publicación:2024
País:España
Institución:Universitat Autònoma de Barcelona
Repositorio:Dipòsit Digital de Documents de la UAB
Idioma:inglés
OAI Identifier:oai:ddd.uab.cat:306339
Acceso en línea:https://ddd.uab.cat/record/306339
https://dx.doi.org/urn:doi:10.3390/genes15060679
Access Level:acceso abierto
Palabra clave:X-linked hypophosphatemia
PHEX gene
Non-canonical splice site variant
Descripción
Sumario:X-linked hypophosphatemia (XLH) is a rare inherited disorder of renal phosphate wasting with a highly variable phenotype caused by loss-of-function variants in the PHEX gene. The diagnosis of individuals with mild phenotypes can be challenging and often delayed. Here, we describe a three-generation family with a very mild clinical presentation of XLH. The diagnosis was unexpectedly found in a 39-year-old woman who was referred for genetic testing due to an unclear childhood diagnosis of a tubulopathy. Genetic testing performed by next-generation sequencing using a kidney disease gene panel identified a novel non-canonical splice site variant in the PHEX gene. Segregation analysis detected that the consultand's father, who presented with hypophosphatemia and decreased tubular phosphate reabsorption, and the consultand's son also carried this variant. RNA studies demonstrated that the non-canonical splice site variant partially altered the splicing of the PHEX gene, as both wild-type and aberrant splicing transcripts were detected in the two male members with only one copy of the PHEX gene. In conclusion, this case contributes to the understanding of the relationship between splicing variants and the variable expressivity of XLH disease. The mild phenotype of this family can be explained by the coexistence of PHEX transcripts with aberrant and wild-type splicing.