Confirmation and refinement of a genetic locus for disseminated superficial actinic porokeratosis (DSAP1) at 12q23.2-24.1

Summary Background Our previous study has identified two loci for disseminated superficial actinic porokeratosis (DSAP), but the genes responsible are still unknown. Objectives To narrow down the candidate regions and to assess candidate genes. Methods A genome‐wide scan and linkage analysis were carried out in a newly collected five‐generation Chinese family with DSAP. In addition, six candidate genes were screened for possible DSAP‐associated mutations. Results DSAP in this family was associated with chromosome 12q. Fine mapping and haplotype construction refined the DSAP1 locus to a 4·4‐cM interval. No disease‐associated mutation was detected in CRY1, C4ST1, TXNRD1, HCF2, CMKLR1 or KIAA0789 genes. Conclusions The DSAP1 locus was localized to a 4·4‐cM interval at chromosome 12q23.2‐24.1. CRY1, C4ST1, TXNRD1, HCF2, CMKLR1 and KIAA0789 genes were not associated with DSAP1.