Novel missense mutations of MVK and FDPS gene in Chinese patients with disseminated superficial actinic porokeratosis

Background and aims: Porokeratosis (PK) is a heterogeneous group of cutaneous keratinization disorders and has five clinical subtypes. DSAP is the most common clinical subtype and is characterized by multiple small, annular, anhidrotic, keratotic lesions predominantly on sun-exposed areas of the skin. It is an autosomal dominantly inherited epidermal keratinization disorder. However, studies on its molecular basis is limited. Materials and methods: We performed mutation analysis of genes in four pedigrees and three sporadic cases of DSAP in the Chinese population. Genomic DNA was extracted from blood samples obtained from patients, unaffected family members, and 100 unrelated individuals. All exons and flanking intron sequences of the mevalonate kinase (MVK) and farnesyl diphosphate synthase (FDPS) genes were amplified. Results: One missense mutation in exon 7 (C.G677A) of the MVK gene was identified in pedigree 3, and one missense mutation in exon 5 (C.C535T) of the FDPS gene was identified in sporadic case 3. No mutation was detected in the MVK and FDPS genes in the remaining three pedigrees and two sporadic cases with DSAP. Conclusion: Our results may be useful for genetic counseling and prenatal diagnosis of affected families and for expanding the repertoire of MVK and FDPS mutations underlying DSAP.