Expanding the clinical spectrum of biglycan-related Meester-Loeys syndrome.

Pathogenic loss-of-function variants in BGN, an X-linked gene encoding biglycan, are associated with Meester-Loeys syndrome (MRLS), a thoracic aortic aneurysm/dissection syndrome. Since the initial publication of five probands in 2017, we have considerably expanded our MRLS cohort to a total of 18 probands (16 males and 2 females). Segregation analyses identified 36 additional BGN variant-harboring family members (9 males and 27 females). The identified BGN variants were shown to lead to loss-of-function by cDNA and Western Blot analyses of skin fibroblasts or were strongly predicted to lead to loss-of-function based on the nature of the variant. No (likely) pathogenic missense variants without additional (predicted) splice effects were identified. Interestingly, a male proband with a deletion spanning the coding sequence of BGN and the 5' untranslated region of the downstream gene (ATP2B3) presented with a more severe skeletal phenotype. This may possibly be explained by expressional activation of the downstream ATPase ATP2B3 (normally repressed in skin fibroblasts) driven by the remnant BGN promotor. This study highlights that aneurysms and dissections in MRLS extend beyond the thoracic aorta, affecting the entire arterial tree, and cardiovascular symptoms may coincide with non-specific connective tissue features. Furthermore, the clinical presentation is more severe and penetrant in males compared to females. Extensive analysis at RNA, cDNA, and/or protein level is recommended to prove a loss-of-function effect before determining the pathogenicity of identified BGN missense and non-canonical splice variants. In conclusion, distinct mechanisms may underlie the wide phenotypic spectrum of MRLS patients carrying loss-of-function variants in BGN.

Treatment of Fungal-Infected Diabetic Wounds with Low Temperature Plasma.

Diabetes mellitus renders patients susceptible to chronic wounds and various infections. Regarding the latter, fungal infections are of particular concern since, although they are the source of significant morbidity and mortality in immunocompromised patients, they are generally resistant to conventional treatment and a definite treatment strategy has not yet been established. Herein, we report the treatment of skin wounds in a diabetic rat model, infected by Candida albicans, with low temperature helium plasma generated in a hand-held atmospheric jet device. A fungal infection was induced on two dorsal skin wounds of the diabetic rats, and one wound was treated with the plasma jet whereas the other served as a control. Histological analysis revealed accelerated skin wound healing and decreased evidence of fungal infection in the plasma-treated group, as compared to the control group. Regeneration of the epidermis and dermis, collagen deposition, and neovascularization were all observed as a result of plasma treatment, but without wound contraction, scar formation or any evidence of thermal damage to the tissue. These findings demonstrate that the He plasma jet is remarkably effective in diabetic skin wounds infected by Candida albicans, thereby providing a promising medical treatment option for diabetes mellitus patients with skin wound and fungal infections.

Classification and correlation of RYR2 missense variants in individuals with catecholaminergic polymorphic ventricular tachycardia reveals phenotypic relationships.

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is predominantly caused by heterozygous missense variants in the cardiac ryanodine receptor, RYR2. However, many RYR2 missense variants are classified as variants of uncertain significance (VUS). We systematically re-evaluated all RYR2 variants in healthy individuals and those with CPVT or arrhythmia using the 2015 American College of Medical Genomics guidelines. RYR2 variants were identified by the NW Genomic Laboratory Hub, from the published literature and databases of sequence variants. Each variant was assessed based on minor allele frequencies, in silico prediction tools and appraisal of functional studies and classified according to the ACMG-AMP guidelines. Phenotype data was collated where available. Of the 326 identified RYR2 missense variants, 55 (16.9%), previously disease-associated variants were reclassified as benign. Application of the gnomAD database of >140,000 controls allowed reclassification of 11 variants more than the ExAC database. CPVT-associated RYR2 variants clustered predominantly between amino acid positions 3949-4332 and 4867-4967 as well as the RyR and IP3R homology-associated and ion transport domains (p < 0.005). CPVT-associated RYR2 variants occurred at more conserved amino acid positions compared with controls, and variants associated with sudden death had higher conservation scores (p < 0.005). There were five potentially pathogenic RYR2 variants associated with sudden death during sleep which were located almost exclusively in the C-terminus of the protein. In conclusion, control sequence databases facilitate reclassification of RYR2 variants but the majority remain as VUS. Notably, pathogenic variants in RYR2 are associated with death in sleep.

Genetic variation in VEGF does not contribute significantly to the risk of congenital cardiovascular malformation.

Several previous studies have investigated the role of common promoter variants in the vascular endothelial growth factor (VEGF) gene in causing congenital cardiovascular malformation (CVM). However, results have been discrepant between studies and no study to date has comprehensively characterised variation throughout the gene. We genotyped 771 CVM cases, of whom 595 had the outflow tract malformation Tetralogy of Fallot (TOF), and carried out TDT and case-control analyses using haplotype-tagging SNPs in VEGF. We carried out a meta-analysis of previous case-control or family-based studies that had typed VEGF promoter SNPs, which included an additional 570 CVM cases. To identify rare variants potentially causative of CVM, we carried out mutation screening in all VEGF exons and splice sites in 93 TOF cases. There was no significant effect of any VEGF haplotype-tagging SNP on the risk of CVM in our analyses of 771 probands. When the results of this and all previous studies were combined, there was no significant effect of the VEGF promoter SNPs rs699947 (OR 1.05 [95% CI 0.95-1.17]); rs1570360 (OR 1.17 [95% CI 0.99-1.26]); and rs2010963 (OR 1.04 [95% CI 0.93-1.16]) on the risk of CVM in 1341 cases. Mutation screening of 93 TOF cases revealed no VEGF coding sequence variants and no changes at splice consensus sequences. Genetic variation in VEGF appears to play a small role, if any, in outflow tract CVM susceptibility.

Pathogenic mitochondrial DNA mutations are common in the general population.

Mitochondrial DNA (mtDNA) mutations are a major cause of genetic disease, but their prevalence in the general population is not known. We determined the frequency of ten mitochondrial point mutations in 3168 neonatal-cord-blood samples from sequential live births, analyzing matched maternal-blood samples to estimate the de novo mutation rate. mtDNA mutations were detected in 15 offspring (0.54%, 95% CI = 0.30-0.89%). Of these live births, 0.00107% (95% CI = 0.00087-0.0127) harbored a mutation not detected in the mother's blood, providing an estimate of the de novo mutation rate. The most common mutation was m.3243A-->G. m.14484T-->C was only found on sub-branches of mtDNA haplogroup J. In conclusion, at least one in 200 healthy humans harbors a pathogenic mtDNA mutation that potentially causes disease in the offspring of female carriers. The exclusive detection of m.14484T-->C on haplogroup J implicates the background mtDNA haplotype in mutagenesis. These findings emphasize the importance of developing new approaches to prevent transmission.

Analysis of the Fc receptor-like-3 (FCRL3) locus in Caucasians with autoimmune disorders suggests a complex pattern of disease association.

CONTEXT: A four-marker haplotype in the 5' region of the Fc receptor-like 3 gene (markers FCRL3_3 to FCRL3_6) has been identified recently as contributing to rheumatoid arthritis (RA) susceptibility in the Japanese population. The promoter FCRL3_3*C allele also showed significant association with autoimmune thyroid disease and systemic lupus erythematosus. These findings raise the possibility that this locus may influence autoimmune disease susceptibility across many populations. PATIENTS AND DESIGN: We analyzed the same four 5' FCRL3 single nucleotide polymorphism markers, together with three additional exonic single nucleotide polymorphisms in the FCRL3 gene, in cohorts of white Caucasians with Graves' disease (n = 625), type 1 diabetes (n = 279), autoimmune Addison's disease (AAD; n = 200), and RA (n = 769). Healthy controls from the United Kingdom (n = 490) and New Zealand (n = 593) were used. RESULTS: Six of the seven FCRL3 markers showed association with AAD (P = 0.005-0.0001), with maximum evidence at the FCRL3_3*T allele [P([corrected]) = 0.0008; odds ratio (OR), 1.61; 5-95% confidence intervals (CIs), 1.26-2.05]. The most common seven-marker FCRL3 haplotype (TGGGAAA) was also found to be significantly associated with AAD (P([corrected]) = 1.1 x 10(-4); OR, 1.71; 5-95% CIs, 1.33-2.18). There was nominal evidence for allelic association at the marker FCRL3_8 in Graves' disease (OR, 1.50; 5-95% CIs, 1.06-2.13) and at FCRL3_9 with RA (OR, 1.25; 5-95% CIs, 1.01-1.54). CONCLUSIONS: The FCRL3 haplotype that is associated with AAD in Caucasians appears to be protective for autoimmune diseases in the Japanese population, demonstrating that this haplotype is unlikely to contain a single primary etiological allele for autoimmunity. Our observations suggest that the susceptibility to autoimmunity at the FCRL3 locus is more complex than initially thought and may extend either side of the currently associated region to include the adjacent FCRL2 gene.

Genetic association studies of the FOXP3 gene in Graves' disease and autoimmune Addison's disease in the United Kingdom population.

Regulatory T lymphocytes play a crucial role in modulating potentially self-reactive clones, and dysfunction of this cell type contributes to autoimmune disease. FOXP3 is a critical determinant of CD(4+)CD(25+)T regulatory (T(reg)) cell development and function. The aim of this study was to investigate whether genetic polymorphisms at the FOXP3 locus predispose to autoimmune endocrinopathies. Five single nucleotide polymorphisms (SNPs) and two microsatellite polymorphisms were genotyped in our Caucasian cohorts of 633 unrelated Graves' disease (GD) subjects, 104 autoimmune Addison's disease (AAD) subjects and 528 healthy controls. SNP genotyping was performed by either restriction enzyme digestion or by primer-extension-MALDI-TOF (matrix-assisted laser desorption/ionisation time-of-flight) assay. Microsatellites were analysed using fluorescent PCR. Case-control analysis was performed using chi(2) testing on contingency tables for allele frequency. Haplotype analysis was performed using the UNPHASED package. No evidence for disease association was found with any of the seven polymorphisms in either of the GD or AAD subjects as compared with controls (P = 0.26-0.94). Haplotype analysis found a weak evidence for the association of a minor haplotype with GD; this was not significant when corrected for multiple testing. This study has found no robust evidence that FOXP3 gene polymorphism contributes to the susceptibility to GD or AAD in the UK population.