一个抗维生素D佝偻病家系PHEX基因的新剪切突变

摘要

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.%目的 确定1个抗维生素D佝偻病家系患者PHEX基因的致病突变,并探讨其与疾病的关系.方法 用Sanger测序法对该家系中2例患者及100名无血缘关系的正常对照的PHEX基因进行突变检测,用逆转录PCR检测相应的mRNA的变化.结果 基因测序结果显示2例患者均发生了PHEX基因的IVS21+2T＞G突变,在100名正常对照中则未检测到该突变.mRNA序列分析证实该突变导致了PHEX基因第21外显子的缺失.结论 PHEX基因的IVS21+ 2T＞G突变是该家系的致病原因.本研究进一步丰富了PHEX基因的突变谱.