Erythropoietic protoporphyria（EPP）, an autosomal dominant disease, is caused by partial deficiency of ferrochelatase（FECH）, which catalyzes the terminal step of heme biosynthesis because of loss-of-function mutati...Erythropoietic protoporphyria（EPP）, an autosomal dominant disease, is caused by partial deficiency of ferrochelatase（FECH）, which catalyzes the terminal step of heme biosynthesis because of loss-of-function mutations in the FECH gene. To date, only a few cases have been described in Asia. In this study, we describe the clinical features of two Chinese patients with EPP, with diagnosis confirmed by the increase of free protoporphyrin in erythrocytes, detection of plasma fluorescence peak at 630–634 nm, and analysis of FECH gene mutations. Using gene scanning, we identified a small deletion in the FECH gene（c.973 delA） in one proband（patient A） and a pathogenic FECH mutation（c.1232 GT） in the other（patient B） and also observed some nucleotide variations（c.798 CG, c.921 AG, IVS1-23 CT, IVS3＋23 AG, IVS9＋35 CT, and IVS3-48 TC） in these patients. The family pedigree of patient A was then established by characterization of the genotype of the patient＇s relatives. We also analyzed the potential perniciousness of the missense mutation with bioinformatic software, Polyphen and Sift. In summary, Chinese EPP patients have similar manifestations to those of Caucasians, and identification of the Chinese FECH gene mutations expands the FECH genotypic spectrum and may contribute to genetic counseling.展开更多
基金supported by the National Basic Research Project(973)of China(No.2012CB934000)the National Distinguished Youth Scholar Grant of China(No.31325010)
文摘Erythropoietic protoporphyria（EPP）, an autosomal dominant disease, is caused by partial deficiency of ferrochelatase（FECH）, which catalyzes the terminal step of heme biosynthesis because of loss-of-function mutations in the FECH gene. To date, only a few cases have been described in Asia. In this study, we describe the clinical features of two Chinese patients with EPP, with diagnosis confirmed by the increase of free protoporphyrin in erythrocytes, detection of plasma fluorescence peak at 630–634 nm, and analysis of FECH gene mutations. Using gene scanning, we identified a small deletion in the FECH gene（c.973 delA） in one proband（patient A） and a pathogenic FECH mutation（c.1232 GT） in the other（patient B） and also observed some nucleotide variations（c.798 CG, c.921 AG, IVS1-23 CT, IVS3＋23 AG, IVS9＋35 CT, and IVS3-48 TC） in these patients. The family pedigree of patient A was then established by characterization of the genotype of the patient＇s relatives. We also analyzed the potential perniciousness of the missense mutation with bioinformatic software, Polyphen and Sift. In summary, Chinese EPP patients have similar manifestations to those of Caucasians, and identification of the Chinese FECH gene mutations expands the FECH genotypic spectrum and may contribute to genetic counseling.
