Genome-wide association and targeted analysis of copy number variants with psoriatic arthritis in German patients

Incidental detection of familial 8p23.2 microduplication encompassing CSMD1 associated with mosaic 46,XY,t(7;8)(q31.2;p23.1)/46,XY at amniocentesis in a pregnancy with no apparent phenotypic abnormality and a favorable outcome

OBJECTIVE

We present incidental detection of familial 8p23.2 microduplication encompassing CSMD1 associated with mosaic 46,XY,t(7;8)(q31.2;p23.1)/46,XY at amniocentesis in a pregnancy with no apparent phenotypic abnormality and a favorable outcome.

CASE REPORT

A 38-year-old, gravida 2, para 1, phenotypically normal woman underwent amniocentesis at 19 weeks of gestation because of advanced maternal age. Amniocentesis revealed a karyotype of 46,XY,t(7;8)(q31.2;p23.1)[2]/46,XY[20]. The parental karyotypes were normal. Array comparative genomic hybridization (aCGH) analysis on the DNA extracted from cultured amniocytes and parental bloods revealed the result of a 2.178-Mb 8p23.2 microduplication encompassing CSMD1, or arr 8p23.2 (3,070,237-5,248,586) × 3.0 [GRCh37 (hg19)] in the fetus and the mother. The father did not have such a microduplicaiton. Prenatal ultrasound findings were unremarkable. At 38 weeks of gestation, a 2880-g phenotypically normal male baby was delivered. All the cord blood, umbilical cord and placenta had the karyotype of 46.XY. When follow-up at age six months, the neonate was normal in phenotype and development.

CONCLUSION

Mosaicism for a balanced reciprocal translocation with a euploid cell line can be a transient and benign condition. Familial 8p23.2 microduplication encompassing CSMD1 can be associated with a favorable outcome.

Genetic underpinnings of the psoriatic spectrum

The psoriatic field includes both rare and common subtypes. Common complex forms include psoriasis vulgaris and psoriatic arthritis. In these subtypes, certain HLA alleles remain the most relevant genetic factors, although genome-wide association studies lead to the detection of more than 80 susceptibility loci. They mainly affect innate and adaptive immunity and explain over 28 % of the heritability. Pustular psoriasis comprises a group of rarer subtypes. Using exome sequencing, several disease genes were identified for mainly generalized pustular psoriasis, and an oligogenic inheritance is likely. Treatment studies based on the affected IL-36 pathway indicate a high response rate in this subtype further supporting the pathophysiological relevance of the affected gene products.

Unraveling the complexities of psoriatic arthritis by the use of -Omics and their relevance for clinical care

-Omic technologies represent a novel approach to unravel ill-defined aspects of psoriatic arthritis (PsA). Large-scale information can be acquired from analysis of affected tissues in PsA via high-throughput studies in the domains of genomics, transcriptomics, epigenetics, proteomics and metabolomics. This is a critical overview of the current knowledge of -omics in PsA, with emphasis on the pathophysiological insights of diagnostic and therapeutic relevance, the advent of novel biomarkers and their potential use for precision medicine in PsA.

Insights into the pathogenesis of psoriatic arthritis from genetic studies

Psoriatic arthritis (PsA) is a relatively common inflammatory arthritis, a spondyloarthritis (SpA), that occurs most often in patients with psoriasis, a common immune-mediated inflammatory skin disease. Both psoriasis and PsA are highly heritable. Genetic and recent genomic studies have identified variants associated with psoriasis and PsA, but variants differentiating psoriasis from PsA are few. In this review, we describe recent developments in understanding the genetic burden of PsA, linkage, association and epigenetic studies. Using pathway analysis, we provide further insights into the similarities and differences between PsA and psoriasis, as well as between PsA and other immune-mediated inflammatory diseases, particularly ankylosing spondylitis, another SpA. Environmental factors that may trigger PsA in patients with psoriasis are also reviewed. To further understand the pathogenetic differences between PsA and psoriasis as well as other SpA, larger cohort studies of well-phenotyped subjects with integrated analysis of genomic, epigenomic, transcriptomic, proteomic and metabolomic data using interomic system biology approaches are required.

The Autoantigen Repertoire and the Microbial RNP World

Although autoimmunity and autoimmune disease (AID) are relatively common, the repertoire of autoantigens is paradoxically very limited. Highly enriched in this autoantigen repertoire are nucleic acids and their binding proteins, which together form large macromolecular structures. Most of these complexes are of ancient evolutionary origin, with homologs throughout multiple kingdoms of life. Why and if these nucleic acid-protein particles drive the development of autoimmunity remains unresolved. Recent advances in our understanding of the microbiome may provide clues about the origins of autoimmunity - and the particular puzzle of why the autoantigen repertoire is so particularly enriched in ribonucleoprotein particles (RNPs). We discuss the possibility that autoimmunity to some RNPs may arise from molecular mimicry to microbial orthologs.

Association between metabolic syndrome and psoriasis: a meta-analysis of observational studies with non-psoriasis control groups

INTRODUCTION

Psoriasis is a highly prevalent condition that affects the quality of life of affected individuals. Several studies have indicated an association between psoriasis and metabolic syndrome (MS). However, the results were inconsistent. The objective of this study was to evaluate the relationship between psoriasis and MS.

MATERIAL AND METHODS

Electronic databases (PubMed, EBSCO, Elsevier, Springer, Wiley, and Cochrane) were searched systematically for published studies up to November 2, 2018. Odds ratio (OR) and 95% confidence interval (CI) were used to evaluate the association between psoriasis and MS. The heterogeneity of the study was estimated with the I² statistic and analyzed by meta-regression and subgroup analyses.

RESULTS

Twenty-two studies with a total of 137,053 participants were included in this meta-analysis. Psoriasis was associated with MS and the combined OR (95% CI) was 2.02 (1.67-2.43). The results showed high heterogeneity (I ² = 83.60%, p < 0.001) and no publication bias among the included studies (p = 0.119). The source of controls may have influenced the heterogeneity according to the meta-regression. There was no heterogeneity in studies with matched non-psoriasis control groups according to the subgroup analysis.

CONCLUSIONS

Psoriasis was associated with MS. The source of the control group was an influencing factor on heterogeneity in this study. Treating for MS in patients with psoriasis might improve psoriasis and reduce the risk of cardiovascular disease.