Investigation of SCN9A Gene Mutation in Primary Erythermalgia

Objective To identify SCN9A gene mutation in a family with severe primary erythermalgia.Methods Clinical data of family were collected and the encoding exons and their flanking sequences of SCN9A gene were amplified and sequenced from genomic DNA samples.Results A heterozygous c.1185C→G was found in exon 9 of the proband,which resulted in N395K amino acid substitution.The mutation was not detected in the proband's healthy mother or 50 unrelated healthy controls.Conclusion The missense mutation of SCN9A gene is the underlying cause of the patient's clinical phenotype.