BACKGROUNDAcne inversa (AI), also called hidradenitis suppurativa, is a chronic, inflammatory, recurrent skin disease of the hair follicle. Familial AI shows autosomal-dominant inheritance caused by mutations in the γ-secretase genes. This study was aimed to identify the specific mutations in the γ-secretase genes in two Chinese families with AI.

METHODSIn this study, two Chinese families with AI were investigated. All the affected individuals in the two families mainly manifested with multiple comedones, pitted scars, and a few inflammatory nodules on their face, neck, trunk, axilla, buttocks, upper arms, and thighs. Reticulate pigmentation in the flexures areas resembled Dowling-Degos disease clinically and pathologically. In addition, one of the affected individuals developed anal canal squamous cell carcinoma. Molecular mutation analysis of γ-secretase genes including PSENEN, PSEN1, and NCSTN was performed by polymerase chain reaction and direct DNA sequencing.

RESULTSTwo novel mutations of PSENEN gene were identified, including a heterozygous missense mutation c.194T>G (p.L65R) and a splice site mutation c.167-2A>G.

CONCLUSIONSThe identification of the two mutations could expand the spectrum of mutations in the γ-secretase genes underlying AI and provide valuable information for further study of genotype-phenotype correlations.