Two closely linked variations in actin cytoskeleton pathway in a Chinese pedigree with disseminated superficial actinic porokeratosis.

Background: Disseminated superficial actinic porokeratosis (DSAP) is an uncommon autosomal dominant chronic keratinization disorder, characterized by multiple superficial keratotic lesions surrounded by a slightly raised keratotic border. Recently, SSH1 was identified as the DSAP candidate gene.

Objective: Our purpose was to determine the locus of DSAP and identify the candidate gene(s) of the disease.

Methods: Genome-wide scanning and linkage analysis were performed in a 6-generation Chinese family with DSAP. The coding exons and promoter region of the candidate genes were screened for the nucleotide variations.

Results: A missense mutation (p.Ser63Asn) in SSH1 and a variation (dbSNP3759383: G>A) in the promoter region of ARPC3 were closely linked with DSAP in the pedigree.

Conclusion: Both SSH1 and ARPC3 are involved in the actin cytoskeleton pathway and interacted with adherent junctions in the epidermal cells. We suggested that cytoskeleton disorganization in epidermal cells was likely associated with the pathogenesis of DSAP.