A mutation in SART3 gene in a Chinese pedigree with disseminated superficial actinic porokeratosis

Abstract

Disseminated superficial actinic porokeratosis (DSAP) is an uncommon autosomal dominant chronic disorder of keratinization, characterized by multiple superficial keratotic lesions surrounded by a slightly raised keratotic border. Thus far, although two loci for DSAP have been identified, and the genetic basis and pathogenesis of this disorder have not been elucidated. To determine the locus of DSAP and identify the candidate gene(s) of the disease. Genome-wide scan and linkage analysis were performed in a six-generation Chinese family with DSAP. The coding exons of the candidate genes were sequenced to analyse and detect the nucleotide variations. Linkage analysis showed that the maximum two-point lod score of 5.56 was obtained with the marker D12S79 at a recombination fraction theta of 0.00. Haplotype analysis defined the critical region for DSAP between D12S330 and D12S1612 on 12q24.1-24.2. By sequence analysis, we found a Val591Met mutation in SART3 in all affected individuals of the family. SART3 is a candidate gene for DSAP, and is possibly involved in the pathogenesis of DSAP.