| Background Nevus sebaceous syndrome(Schimmelpenning syndrome,NSS)has been placed under the umbrella term of epidermal nevus syndrome,in which the nevus sebaceous(Sebaceous nevus,NS),a congenital hamartomatous lesion,is associated with anomalies involving the brain,eyes,and bones.Abnormal expression of multiple genes were reported to play a key role in the occurrence and development of NSS and NS.Objective To study the clinical features and causative gene mutations in a Chinese patient with NSS and to identify the the key mutation sites by subsequent validation.Methods In our study,the lesions and the contralateral normal tissues of the patient were excised to extract DNA.Then whole-exome sequencing was performed to investigate the gene mutations,followed by Sanger sequencing performed in 36 cases of NS to identify the mutations.Results A Chinese family with NSS was described,and the proband was a 17-year-old girl showing generalized brown verrucous proliferative skin lesions on the fight side of the head,face and neck.Mutation analysis of the whole genome exon sequencing was performed,3 potentially harmful mutation sites were obtained by using SIFT and Polyphen software.Of 36 cases of NS,one showed KRASA(c.35G>A,p.G12D)heterozygosity mutation.The mutation frequency of KRAS gene was found to be consistent with previous reports.Conclusion NS,a kind of benign tumor originated from primitive multipotential epithelial germ,is the main skin manifestation of NSS.In spite of its slow development and biological benign character,the impact on appearance,and advanced secondary basal cell carcinoma,syringocystadenoma papilliferum,trichoblastoma and other skin tumors,accompanied by muti-system abnormalities in NSS,which seriously influence the life of patients.In this study,the mutation of KRAS was found in both NSS and NS,which was likely to be related to the pathogenesis of NSS,providing new clues in the understanding of genetic heterogeneity and better genetic counselling of patients with the NSS and NS. |
