Objective: To identify potential mutation of PHEX gene in two patients from a family affected with X-linked hypophosphatemia (XLH).
Methods: PCR and Sanger sequencing were performed on blood samples from the patients and 100 healthy controls. Reverse transcription-PCR (RT-PCR) was used to determine the mRNA expression in patient samples.
Results: A splicing site mutation, IVS21+2T>G, was found in the PHEX gene in both patients but not among the 100 healthy controls. RT-PCR confirmed that exon 21 of the PHEX gene was deleted.
Conclusion: The novel splicing mutation IVS21+2T>G of the PHEX gene probably underlies the XLH in this pedigree. At the mRNA level, the mutation has led to removal of exon 21 and shift of the open reading frame (p.Val691fsx), resulting in premature termination of protein translation.