Primary localized cutaneous amyloidosis (PLCA) is a chronic skin disorder, caused by amyloid material deposition in the upper dermis. Autosomal dominant PLCA has been mapped earlier to pathogenic missense mutations in the OSMR gene, which encodes the oncostatin M receptor ß subunit (OSMRß). OSMRß is interleukin-6 family cytokine receptors and possesses two ligands, oncostatin M and interleukin-31, which both have biologic roles in inflammation and keratinocyte cell proliferation, differentiation, and apoptosis. Here, we identified a new OSMR mutation in a Kurdish family for the first time. Blood samples were taken from all the affected individuals in the family. DNA extraction was performed using salting out technique. Primers were designed for intron flanking individual exons of OSMR gene which were subjected to direct sequencing after PCR amplification for each sample. Sequencing showed a C/T substitution at position 613 in the proband. This mutation results in an L613S (leucine 613 to serine) amino acid change. The identified mutation was observed in all affected family members but not in 100 ethnically matched healthy controls. Elucidating the molecular basis of familial PLCA provides new insight into mechanisms of itch in human skin and may lead to new therapeutic targets for pruritus.

Familial Mediterranean fever (FMF) is the most prevalent autoinflammatory disease. Typical findings are recurrent fever attacks with serositis, skin rash, and synovitis. FMF is caused by mutations in the MEFV gene, encoding pyrin protein. Pyrin functions in innate immunity and triggers inflammation via inflammatory mediators' production and acts as the primary regulatory component of the inflammasome. On the other hand, various miRNAs play crucial roles in the pathogenesis of different types of cancers and immune-related and neurodegenerative diseases. However, their association with FMF is still unclear. Therefore, in this study, we assessed the roles of selected thirteen miRNAs associated with immune functions. We recruited genetically diagnosed 28 FMF patients and 28 healthy individuals. The expression profiling of the miRNAs was determined by qRT-PCR and normalized to SNORD61. Our analysis revealed that miR-34a-5p, miR-142-3p, miR-216a-5p, miR-340-5p, miR-429, and miR-582-5p were upregulated, whereas miR-107, miR-569, and miR-1304-5p were downregulated in the FMF patients. Among them, miR-107 was found to be the most remarkable in M694V homozygous mutants compared to other homozygous mutants. During clinical follow-up of the patients with M694V mutation, which is closely related to amyloidosis, evaluation of mir-107 expression might be crucial and suggestive. Our results showed that miRNAs might serve a function in the pathogenesis of FMF. Further studies may provide novel and effective diagnostic and therapeutic agents that target examined miRNAs. Targeting miRNAs in FMF seems to be promising and may yield a new generation of rational therapeutics and diagnostic or monitoring tools enabling FMF treatment.