1 - Hospital do Espírito Santo de Évora, Évora, Portugal.
2 - Centro Hospitalar e Universitário de Lisboa Central, Hospital Dona Estefânia, Lisboa, Portugal.
3 -Hospital de Santarém, Santarém, Portugal.
4 - Centro Hospitalar e Universitário de Lisboa Central, Hospital Dona Estefânia, Unidade de Nefrologia Pediátrica, Lisboa, Portugal.
5 - Hospital de Vila Franca de Xira, Vila Franca de Xira, Lisboa, Portugal.
6 - Centro Hospitalar e Universitário de Lisboa Central, Hospital Dona Estefânia, Departamento de Genética Médica, Lisboa, Portugal.
- Publicação em versão integral - Braz. J. Nephrol. (J. Bras. Nefrol.) 2020. Ahead of print
Introduction: Phosphopenic rickets may be caused by mutations in the PHEX gene (phosphate regulating endopeptidase homolog X-linked). Presently, more than 500 mutations in the PHEX gene have been found to cause hypophosphatemic rickets.
Clinical Report The authors report a clinical case of a 4-year-old girl with unremarkable family history, who presented with failure to thrive and bowing of the legs. Laboratory tests showed hypophosphatemia, elevated alkaline phosphatase, normal calcium, mildly elevated PTH and normal levels of 25(OH)D and 1.25(OH)D. The radiological study showed bone deformities of the radius and femur. Clinical diagnosis of phosphopenic rickets was made and the genetic study detected a heterozygous likely pathogenic variant of the PHEX gene: c.767_768del (p.Thr256Serfs*7). This variant was not previously described in the literature or databases.
Conclusion: Knowledge about new mutations can improve patient’s outcome. Genetic analysis can help to establish a genotype-phenotype correlation.
Keywords: Rickets, Hypophosphatemic; Mutation; PHEX.