Abstract: Objective To target the disease gene of disseminated superficial form of porokeratosis (DSP) in a six-generation of a Chinese family including a total of 254 family members in Shandong province. Methods The clinical data and the peripheral blood samples were collected in the pedigree members. The genomic DNA was extracted from the blood samples. A genome-wide scan was performed using 382 pairs of primers labelled with fluorescent stain. The primers were designed for human autosomes. The sequencing results were analyzed by the software of Genescan and Genotype. Linkage analysis was processed by Linkage software package to define the region of disease gene. For fine targeting the disease gene, other 10 micro-satellite markers for the above region were set up for further fine sequencing. Results We obtained the maximum two-point LOD scores of 3.06 at micro-satellite marker D12S78 (recombination fraction θ=0.00). After fine mapping, the DSP gene is located within a 38.5 cM region between markers D12S326 and D12S79. Conclusion The DSP gene is mapped to chromosome 12q21.2~24.2.

Key words: Porokeratosis, Sequence analysis, DNA, Chromosome mapping, Linkage (Genetics)