Abstract:

Li Min, Zhou Naihui, Song Linyi, Yang Ziliang, Wang Miaomiao, Yu Xiuqin Department of Dermatology, the First Affiliated Hospital of Soochow University, Suzhou 215006, China Corresponding author: Zhou Naihui, Email: zhounaihui@163.com 【Abstract】 Objective To report a case of pseudoxanthoma elasticum, and to analyze mutations of the ABCC6 gene in the family with pseudoxanthoma elasticum. Methods Clinical data were obtained from a female patient with pseudoxanthoma elasticum and analyzed. Blood samples were collected from the proband, her parents and son, as well as 100 unrelated healthy human controls. Genomic DNA was extracted from these blood samples. PCR was performed to amplify 31 exons of the ABCC6 gene followed by direct DNA sequencing. The function of the protein encoded by the ABCC6 gene was predicted. Results The phenotypes of the patient′s parents and son were all normal. Mutation analysis of the ABCC6 gene revealed compound heterozygous mutations c.373G > A （p.E125K） and c.3703C > T （p.R1235W） in the proband, a heterozygous mutation c.3703C > T （p.R1235W） in the proband′s mother, and a heterozygous mutation c.373G > A （p.E125K） in the proband′s father and son. However, neither of the above mutations was found in the 100 unrelated healthy controls. Interspecific sequence alignment showed that glutamic acid at position 125 and arginine at position 1235 of the protein encoded by the ABCC6 gene were highly evolutionarily conserved. As SIFT and Polyphen?2 softwares showed, the mutations c.373G > A （p.E125K） and c.3703C > T （p.R1235W） were both predicted to be detrimental variations. Conclusion The compound heterozygous mutations c.373G > A （p.E125K） and c.3703C > T （p.R1235W） in the ABCC6 gene may be responsible for the occurrence of pseudoxanthoma elasticum in this patient.