RESUMEN
BACKGROUND: Trichilemmal cysts (TCs) are common intradermal or subcutaneous cysts, which are commonly sporadic and rarely autosomal dominantly inherited. However, little is known about the disease-determining genes in families with TCs exhibiting Mendelian inheritance. OBJECTIVE: The aim of this study was to identify the causative gene in a family with TCs. METHODS: Whole-exome sequencing was performed on a TCs family to identify the candidate gene. Sanger sequencing was conducted to validate the candidate variants and familial segregation. RESULTS: We identified the heterozygous variant c.3G>C (p.Met1?) within the BPIFC gene. Sanger sequencing confirmed the cosegregation of this variant with the TCs phenotype in the family by demonstrating the presence of the heterozygous variant in all the 12 affected and absence in all the seven unaffected individuals. This variant was found to be absent in dbSNP141, 1,000 Genomes database and 500 ethnicity matched controls. CONCLUSION: Our results imply that BPIFC is a causative gene in this Chinese family with hereditary TCs. Further studies should be performed to validate the role of BPIFC in the pathogenesis of this disease.