Porokeratosis (PK) is a heterogeneous group of keratinization disorders. No causal genes except MVK have been identified, even though the disease was linked to several genomic loci. Here, we performed massively parallel sequencing and exonic CNV screening of 12 isoprenoid genes in 134 index PK patients (61 familial and 73 sporadic) and identified causal mutations in three novel genes (PMVK, MVD, and FDPS) in addition to MVK in the mevalonate pathway. Allelic expression imbalance (AEI) assays were performed in 13 lesional tissues. At least one mutation in one of the four genes in the mevalonate pathway was found in 60 (98%) familial and 53 (73%) sporadic patients, which suggests that isoprenoid biosynthesis via the mevalonate pathway may play a role in the pathogenesis of PK. Significantly reduced expression of the wild allele was common in lesional tissues due to gene conversion or some other unknown mechanism. A G-to-A RNA editing was observed in one lesional tissue without AEI. In addition, we observed correlations between the mutations in the four mevalonate pathway genes and clinical manifestations in the PK patients, which might support a new and simplified classification of PK under the guidance of genetic testing.DOI:
http://dx.doi.org/10.7554/eLife.06322.001
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. Thus far, although two loci for DSAP have been identified, the genetic basis and pathogenesis of this disorder have not been elucidated yet. In this study, we performed a genome-wide linkage analysis in three Chinese affected families and localized the gene in an 8.0 cM interval defined by D12S330 and D12S354 on chromosome 12. Upon screening 30 candidate genes, we identified a missense mutation, p.Ser63Asn in SSH1 in one family, a frameshift mutation, p.Ser19CysfsX24 in an alternative variant (isoform f) of SSH1 in another family, and a frameshift mutation, p.Pro27ProfsX54 in the same alternative variant in one non-familial case with DSAP. SSH1 encodes a phosphatase that plays a pivotal role in actin dynamics. Our data suggested that cytoskeleton disorganization in epidermal cells is likely associated with the pathogenesis of DSAP.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.