Abstract: Objective To identify the genetic locus for disseminated superficial actinic porokeratosis(DSAP).Methods Genome DNA was extracted from the whole blood of the family members of a pedigree of DSAP.Genotyping on chromosome 12q that had been identified was performed by using 7 microsatellite markers to scan the family members of DSAP and analysed with LINKAGE(5.1V ersion).Results A maximum 2-point lod score of 5.15 with marker D12S79 at a recombination fraction(θ)=0.00was found.Conclusion Our study supports that DSAP gene localizes at the long arm of chromosome 12,which was first reported in the literature.

Key words: Disseminated superficial actinic porokeratosis, Pedigree, Microsatellite marker, Genecan, Linkage analysis