A novel large deletion of the CYLD gene causes CYLD cutaneous syndrome in a Chinese family

BACKGROUND: CYLD cutaneous syndrome (CCS; syn. Brooke‐Spiegler syndrome) is a rare autosomal dominant hereditary disease characterized by multiple adnexal skin tumors including cylindromas, spiradenomas, and trichoepitheliomas. More than 100 germline mutations of the cylindromatosis (CYLD) gene have been reported in CCS and most of them are frameshift mutations or small alterations. METHODS: We identified a large, three‐generation Chinese family with CCS, which consisted of 18 living family members, including six affected individuals. To explore the molecular biology of this family, we carried out targeted next‐generation sequencing and Affymetrix CytoScan HD SNP array to analyze the mutation in the CYLD gene. RESULTS: A novel large deletion mutation, NC_000016.9:g.(50826498_50827517)_(50963389‐50967346)del was found in the proband of this family. This deletion results in the loss of a nearly 140 kb fragment of the CYLD gene, spanning exons 17 ~ 20, which represent the coding regions of the ubiquitin‐specific protease domain. Further quantitative polymerase chain reaction proved that all patients and two proband‐related family members carried this large deletion. CONCLUSIONS: Our study expands the types of mutations in CCS and will undoubtedly provide valuable information for genetic counseling for families affected by the condition.