Abstract: MA Jun-hong*, WANG Xin, XIAO Sheng-xiang. *Department of Dermatology, First Affiliated Hospital of Tsinghua University, Beijing 100016, China Corresponding author: MA Jun-hong, Email: majh_1@163.com 【Abstract】 Objective To investigate the relationship between the genotype and phenotype of erythropoietic protoporphyria （EPP） in a family. Methods Venous blood samples were collected from two patients with EPP as well as their asymptomatic parents and grandmother. PCR was performed to assess the mutation of FECH gene, and real-time quantitative PCR to detect the expression of FECH gene. Results A mutation IVS3 + 1G > A was detected in the two patients and their mother. Haplotype analysis showed that both patients with photosensitivity carried the wild-type low-expressed allele IVS3-48C, while their mother, the asymptomatic carrier, harbored the normal allele IVS3-48T. As real-time PCR showed, the expression intensity of FECH gene gradually increased from patients, asymptomatic patients to normal individuals. Conclusion The difference in expression intensity of FECH gene may contribute to the variability in clinical presentation of EPP.

Key words: Protoporphyria, erythropoietic