Integrative miRNA-mRNA profiling of human epidermis: unique signature of SCN9A painful neuropathy.

Personalized management of neuropathic pain is an unmet clinical need due to heterogeneity of the underlying aetiologies, incompletely understood pathophysiological mechanisms and limited efficacy of existing treatments. Recent studies on microRNA in pain preclinical models have begun to yield insights into pain-related mechanisms, identifying nociception-related species differences and pinpointing potential drug candidates. With the aim of bridging the translational gap towards the clinic, we generated a human pain-related integrative miRNA and mRNA molecular profile of the epidermis, the tissue hosting small nerve fibres, in a deeply phenotyped cohort of patients with sodium channel-related painful neuropathy not responding to currently available therapies. We identified four miRNAs strongly discriminating patients from healthy individuals, confirming their effect on differentially expressed gene targets driving peripheral sensory transduction, transmission, modulation and post-transcriptional modifications, with strong effects on gene targets including NEDD4. We identified a complex epidermal miRNA-mRNA network based on tissue-specific experimental data suggesting a cross-talk between epidermal cells and axons in neuropathy pain. Using immunofluorescence assay and confocal microscopy, we observed that Nav1.7 signal intensity in keratinocytes strongly inversely correlated with NEDD4 expression that was downregulated by miR-30 family, suggesting post-transcriptional fine tuning of pain-related protein expression. Our targeted molecular profiling advances the understanding of specific neuropathic pain fine signatures and may accelerate process towards personalized medicine in patients with neuropathic pain.

Autophagy Markers Are Altered in Alzheimer's Disease, Dementia with Lewy Bodies and Frontotemporal Dementia.

The accumulation of protein aggregates defines distinct, yet overlapping pathologies such as Alzheimer's disease (AD), dementia with Lewy bodies (DLB), and frontotemporal dementia (FTD). In this study, we investigated ATG5, UBQLN2, ULK1, and LC3 concentrations in 66 brain specimens and 120 plasma samples from AD, DLB, FTD, and control subjects (CTRL). Protein concentration was measured with ELISA kits in temporal, frontal, and occipital cortex specimens of 32 AD, 10 DLB, 10 FTD, and 14 CTRL, and in plasma samples of 30 AD, 30 DLB, 30 FTD, and 30 CTRL. We found alterations in ATG5, UBQLN2, ULK1, and LC3 levels in patients; ATG5 and UBQLN2 levels were decreased in both brain specimens and plasma samples of patients compared to those of the CTRL, while LC3 levels were increased in the frontal cortex of DLB and FTD patients. In this study, we demonstrate alterations in different steps related to ATG5, UBQLN2, and LC3 autophagy pathways in DLB and FTD patients. Molecular alterations in the autophagic processes could play a role in a shared pathway involved in the pathogenesis of neurodegeneration, supporting the hypothesis of a common molecular mechanism underlying major neurodegenerative dementias and suggesting different potential therapeutic targets in the autophagy pathway for these disorders.

Genetic Profiling of Sodium Channels in Diabetic Painful and Painless and Idiopathic Painful and Painless Neuropathies.

Neuropathic pain is a frequent feature of diabetic peripheral neuropathy (DPN) and small fiber neuropathy (SFN). Resolving the genetic architecture of these painful neuropathies will lead to better disease management strategies, counselling and intervention. Our aims were to profile ten sodium channel genes (SCG) expressed in a nociceptive pathway in painful and painless DPN and painful and painless SFN patients, and to provide a perspective for clinicians who assess patients with painful peripheral neuropathy. Between June 2014 and September 2016, 1125 patients with painful-DPN (n = 237), painless-DPN (n = 309), painful-SFN (n = 547) and painless-SFN (n = 32), recruited in four different centers, were analyzed for SCN3A, SCN7A-SCN11A and SCN1B-SCN4B variants by single molecule Molecular inversion probes-Next Generation Sequence. Patients were grouped based on phenotype and the presence of SCG variants. Screening of SCN3A, SCN7A-SCN11A, and SCN1B-SCN4B revealed 125 different (potential) pathogenic variants in 194 patients (17.2%, n = 194/1125). A potential pathogenic variant was present in 18.1% (n = 142/784) of painful neuropathy patients vs. 15.2% (n = 52/341) of painless neuropathy patients (17.3% (n = 41/237) for painful-DPN patients, 14.9% (n = 46/309) for painless-DPN patients, 18.5% (n = 101/547) for painful-SFN patients, and 18.8% (n = 6/32) for painless-SFN patients). Of the variants detected, 70% were in SCN7A, SCN9A, SCN10A and SCN11A. The frequency of SCN9A and SCN11A variants was the highest in painful-SFN patients, SCN7A variants in painful-DPN patients, and SCN10A variants in painless-DPN patients. Our findings suggest that rare SCG genetic variants may contribute to the development of painful neuropathy. Genetic profiling and SCG variant identification should aid in a better understanding of the genetic variability in patients with painful and painless neuropathy, and may lead to better risk stratification and the development of more targeted and personalized pain treatments.

The PINK1 p.Asn521Thr Variant Is Associated with Earlier Disease Onset in GRN/C9orf72 Frontotemporal Lobar Degeneration.

Genetic frontotemporal lobar degeneration (FTLD) is characterized by heterogeneous phenotypic expression, with a disease onset highly variable even in patients carrying the same mutation. Herein we investigated if variants in lysosomal genes modulate the age of onset both in FTLD due to GRN null mutations and C9orf72 expansion. In a total of 127 subjects (n = 74 GRN mutations and n = 53 C9orf72 expansion carriers), we performed targeted sequencing of the top 98 genes belonging to the lysosomal pathway, selected based on their high expression in multiple brain regions. We described an earlier disease onset in GRN/C9orf72 pedigrees in subjects carrying the p.Asn521Thr variant (rs1043424) in PTEN-induced kinase 1 (PINK1), a gene that is already known to be involved in neurodegenerative diseases. We found that: (i) the PINK1 rs1043424 C allele is significantly associated with the age of onset; (ii) every risk C allele increases hazard by 2.11%; (iii) the estimated median age of onset in homozygous risk allele carriers is 10-12 years earlier than heterozygous/wild type homozygous subjects. A replication study in GRN/C9orf72 negative FTLD patients confirmed that the rs1043424 C allele was associated with earlier disease onset (-5.5 years in CC versus A carriers). Understanding the potential mechanisms behind the observed modulating effect of the PINK1 gene in FTLD might prove critical for identifying biomarkers and/or designing drugs to modify the age of onset, especially in GRN/C9orf72-driven disease.

Peripheral Ion Channel Gene Screening in Painful- and Painless-Diabetic Neuropathy.

Neuropathic pain is common in diabetic peripheral neuropathy (DN), probably caused by pathogenic ion channel gene variants. Therefore, we performed molecular inversion probes-next generation sequencing of 5 transient receptor potential cation channels, 8 potassium channels and 2 calcium-activated chloride channel genes in 222 painful- and 304 painless-DN patients. Twelve painful-DN (5.4%) patients showed potentially pathogenic variants (five nonsense/frameshift, seven missense, one out-of-frame deletion) in ANO3 (n = 3), HCN1 (n = 1), KCNK18 (n = 2), TRPA1 (n = 3), TRPM8 (n = 3) and TRPV4 (n = 1) and fourteen painless-DN patients (4.6%-three nonsense/frameshift, nine missense, one out-of-frame deletion) in ANO1 (n = 1), KCNK18 (n = 3), KCNQ3 (n = 1), TRPA1 (n = 2), TRPM8 (n = 1), TRPV1 (n = 3) and TRPV4 (n = 3). Missense variants were present in both conditions, presumably with loss- or gain-of-functions. KCNK18 nonsense/frameshift variants were found in painless/painful-DN, making a causal role in pain less likely. Surprisingly, premature stop-codons with likely nonsense-mediated RNA-decay were more frequent in painful-DN. Although limited in number, painful-DN patients with ion channel gene variants reported higher maximal pain during the night and day. Moreover, painful-DN patients with TRP variants had abnormal thermal thresholds and more severe pain during the night and day. Our results suggest a role of ion channel gene variants in neuropathic pain, but functional validation is required.

Peripheral Ion Channel Genes Screening in Painful Small Fiber Neuropathy.

Neuropathic pain is a characteristic feature of small fiber neuropathy (SFN), which in 18% of the cases is caused by genetic variants in voltage-gated sodium ion channels. In this study, we assessed the role of fifteen other ion channels in neuropathic pain. Patients with SFN (n = 414) were analyzed for ANO1, ANO3, HCN1, KCNA2, KCNA4, KCNK18, KCNN1, KCNQ3, KCNQ5, KCNS1, TRPA1, TRPM8, TRPV1, TRPV3 and TRPV4 variants by single-molecule molecular inversion probes-next-generation sequencing. These patients did not have genetic variants in SCN3A, SCN7A-SCN11A and SCN1B-SCN4B. In twenty patients (20/414, 4.8%), a potentially pathogenic heterozygous variant was identified in an ion-channel gene (ICG). Variants were present in seven genes, for two patients (0.5%) in ANO3, one (0.2%) in KCNK18, two (0.5%) in KCNQ3, seven (1.7%) in TRPA1, three (0.7%) in TRPM8, three (0.7%) in TRPV1 and two (0.5%) in TRPV3. Variants in the TRP genes were the most frequent (n = 15, 3.6%), partly in patients with high mean maximal pain scores VAS = 9.65 ± 0.7 (n = 4). Patients with ICG variants reported more severe pain compared to patients without such variants (VAS = 9.36 ± 0.72 vs. VAS = 7.47 ± 2.37). This cohort study identified ICG variants in neuropathic pain in SFN, complementing previous findings of ICG variants in diabetic neuropathy. These data show that ICG variants are central in neuropathic pain of different etiologies and provides promising gene candidates for future research.

Genome-Wide Meta-Analysis Identifies Three Novel Susceptibility Loci and Reveals Ethnic Heterogeneity of Genetic Susceptibility for IgA Nephropathy.

BACKGROUND: Eighteen known susceptibility loci for IgAN account for only a small proportion of IgAN risk. METHODS: Genome-wide meta-analysis was performed in 2628 patients and 11,563 controls of Chinese ancestry, and a replication analysis was conducted in 6879 patients and 9019 controls of Chinese descent and 1039 patients and 1289 controls of European ancestry. The data were used to assess the association of susceptibility loci with clinical phenotypes for IgAN, and to investigate genetic heterogeneity of IgAN susceptibility between the two populations. Imputation-based analysis of the MHC/HLA region extended the scrutiny. RESULTS: Identification of three novel loci (rs6427389 on 1q23.1 [P=8.18×10-9, OR=1.132], rs6942325 on 6p25.3 [P=1.62×10-11, OR=1.165], and rs2240335 on 1p36.13 [P=5.10×10-9, OR=1.114]), implicates FCRL3, DUSP22.IRF4, and PADI4 as susceptibility genes for IgAN. Rs2240335 is associated with the expression level of PADI4, and rs6427389 is in high linkage disequilibrium with rs11264799, which showed a strong expression quantitative trail loci effect on FCRL3. Of the 24 confirmed risk SNPs, six showed significant heterogeneity of genetic effects and DEFA showed clear evidence of allelic heterogeneity between the populations. Imputation-based analysis of the MHC region revealed significant associations at three HLA polymorphisms (HLA allele DPB1*02, AA_DRB1_140_32657458_T, and AA_DQA1_34_32717152) and two SNPs (rs9275464 and rs2295119). CONCLUSIONS: A meta-analysis of GWAS data revealed three novel genetic risk loci for IgAN, and three HLA polymorphisms and two SNPs within the MHC region, and demonstrated the genetic heterogeneity of seven loci out of 24 confirmed risk SNPs.  These variants may explain susceptibility differences between Chinese and European populations.

Diagnostic criteria for small fibre neuropathy in clinical practice and research.

The diagnostic criteria for small fibre neuropathy are not established, influencing the approach to patients in clinical practice, their access to disease-modifying and symptomatic treatments, the use of healthcare resources, and the design of clinical trials. To address these issues, we performed a reappraisal study of 150 patients with sensory neuropathy and a prospective and follow-up validation study of 352 new subjects with suspected sensory neuropathy. Small fibre neuropathy diagnostic criteria were based on deep clinical phenotyping, quantitative sensory testing (QST) and intraepidermal nerve fibre density (IENFD). Small fibre neuropathy was ruled out in 5 of 150 patients (3.3%) of the reappraisal study. Small fibre neuropathy was diagnosed at baseline of the validation study in 149 of 352 patients (42.4%) based on the combination between two clinical signs and abnormal QST and IENFD (69.1%), abnormal QST alone (5.4%), or abnormal IENFD alone (20.1%). Eight patients (5.4%) had abnormal QST and IENFD but no clinical signs. Further, 38 patients complained of sensory symptoms but showed no clinical signs. Of those, 34 (89.4%) had normal QST and IENFD, 4 (10.5%) had abnormal QST and normal IENFD, and none had abnormal IENFD alone. At 18-month follow-up, 19 of them (56%) reported the complete recovery of symptoms and showed normal clinical, QST and IENFD findings. None of those with one single abnormal test (QST or IENFD) developed clinical signs or showed abnormal findings on the other test. Conversely, all eight patients with abnormal QST and IENFD at baseline developed clinical signs at follow-up. The combination of clinical signs and abnormal QST and/or IENFD findings can more reliably lead to the diagnosis of small fibre neuropathy than the combination of abnormal QST and IENFD findings in the absence of clinical signs. Sensory symptoms alone should not be considered a reliable screening feature. Our findings demonstrate that the combined clinical, functional and structural approach to the diagnosis of small fibre neuropathy is reliable and relevant both for clinical practice and clinical trial design.

A red orange and lemon by-products extract rich in anthocyanins inhibits the progression of diabetic nephropathy.

The major cause of end-stage renal disease is the diabetic nephropathy. Oxidative stress contributes to the development of type II diabetes mellitus (T2DM). In this study we have evaluated the effect of a diet with a new standardized of red orange and lemon extract (RLE) rich in anthocyanins (ANT) in the progression of the kidney disease on Zucker diabetic fatty rats. Oxidative stress and renal function were analyzed. In diabetic rats, the RLE restored the blood glucose levels, body weight, and normalized the reactive oxygen species (ROS) total pathways. The kidney inflammation, in diabetic rats, has not shown significant change, showing that the oxidative stress rather than to inflammatory processes is a triggering factor in the renal complication associated with T2DM. Therefore, the administration of the RLE prevents this complication and this effect could be related to the inhibition of ROS production.

The risk of nephrolithiasis is causally related to inactive matrix Gla protein, a marker of vitamin K status: a Mendelian randomization study in a Flemish population.

Background: Vitamin K (VK)-dependent γ-glutamate carboxylation and serine phosphorylation activate matrix Gla protein (MGP) to a potent locally acting inhibitor of calcification. Nephrolithiasis represents a process of unwanted calcification associated with substantial mortality and high recurrence rates. We hypothesized that the risk of nephrolithiasis increases with VK shortage, as exemplified by higher plasma levels of desphospho-uncarboxylated MGP (dp-ucMGP). Methods: In 1748 randomly recruited Flemish individuals (51.1% women; mean age 46.8 years), we determined dp-ucMGP and the prevalence of nephrolithiasis at baseline (April 1996-February 2015) and its incidence during follow-up until March 2016. We estimated the multivariable-adjusted relative risk associated with the doubling of dp-ucMGP, using logistic or Cox regression. We did a Mendelian randomization analysis using four MGP genotypes as instrumental variables. Results: With adjustments applied for sex, age and 24-h urinary volume and calcium excretion, the odds of having prevalent nephrolithiasis [n = 144 (8.2%)] associated with dp-ucMGP was 1.31 [95% confidence interval (CI) 1.04-1.64; P = 0.022]. dp-ucMGP levels were associated (P ≤ 0.001) with MGP variants rs2098435, rs4236 and rs2430692. In the Mendelian analysis, the causal odds ratio was 3.82 (95% CI 1.15-12.7; P = 0.029). The incidence of nephrolithiasis over 12.0 years (median) was 37 cases (0.2%). With similar adjustments as before, the hazard ratio in relation to dp-ucMGP was 2.48 (95% CI 1.71-3.61; P < 0.001). Additional adjustment for a nephrolithiasis propensity score produced consistent results. Conclusion: Higher levels of inactive dp-ucMGP may be causally associated with the risk of nephrolithiasis. Whether or not VK deficiency plays a role in these observations remains to be firmly established.

A novel SCN9A splicing mutation in a compound heterozygous girl with congenital insensitivity to pain, hyposmia and hypogeusia.

Congenital insensitivity to pain (CIP) is a rare autosomal recessive disorder presenting with a spectrum of clinical features caused by mutations in different genes. A 10-year-old girl with CIP, hyposmia and hypogeusia, and her unaffected twin and parents underwent next generation sequencing of SCN9A exons and flanking splice sites. Transcript analysis from whole blood successfully assayed the effect of the mutation on the mRNA splicing by polymerase chain reaction amplification on cDNA and Sanger sequencing. We identified the novel splicing variant c.1108-2A>G compound with the p.Arg896Gln (c.2687G>A) missense mutation previously described in a homozygous patient. The new intronic variant was predicted to induce exon 10 skipping. Conversely, SCN9A mRNA assay demonstrated its partial deletion with a loss of 46 nucleotides causing a premature stop codon in position p.Gln369 (NP_002968). Genetic analysis showed that the two variants were biallelic, being the mother and brother heterozygous carriers of the missense mutation, and the father heterozygous for the splicing mutation. Skin biopsy showed lack of Meissner's corpuscles, loss of epidermal nociceptors and normal autonomic organ innervation. We report a novel splicing mutation and provide clues on its pathogenic effect, broadening the spectrum of genotypes and phenotypes associated to CIP.

SOS2 and ACP1 Loci Identified through Large-Scale Exome Chip Analysis Regulate Kidney Development and Function.

Genome-wide association studies have identified >50 common variants associated with kidney function, but these variants do not fully explain the variation in eGFR. We performed a two-stage meta-analysis of associations between genotypes from the Illumina exome array and eGFR on the basis of serum creatinine (eGFRcrea) among participants of European ancestry from the CKDGen Consortium (nStage1: 111,666; nStage2: 48,343). In single-variant analyses, we identified single nucleotide polymorphisms at seven new loci associated with eGFRcrea (PPM1J, EDEM3, ACP1, SPEG, EYA4, CYP1A1, and ATXN2L; PStage1<3.7×10-7), of which most were common and annotated as nonsynonymous variants. Gene-based analysis identified associations of functional rare variants in three genes with eGFRcrea, including a novel association with the SOS Ras/Rho guanine nucleotide exchange factor 2 gene, SOS2 (P=5.4×10-8 by sequence kernel association test). Experimental follow-up in zebrafish embryos revealed changes in glomerular gene expression and renal tubule morphology in the embryonic kidney of acp1- and sos2-knockdowns. These developmental abnormalities associated with altered blood clearance rate and heightened prevalence of edema. This study expands the number of loci associated with kidney function and identifies novel genes with potential roles in kidney formation.

Next-generation sequencing of a family with a high penetrance of monoclonal gammopathies for the identification of candidate risk alleles.

BACKGROUND: The authors describe a family with a high penetrance of plasma cell dyscrasias, suggesting inheritance of an autosomal dominant risk allele. METHODS: The authors performed whole-exome sequencing and reported on a combined approach aimed at the identification of causative variants and risk loci, using the wealth of data provided by this approach. RESULTS: The authors identified gene mutations and single-nucleotide polymorphisms of potential significance, and pinpointed a known risk locus for myeloma as a potential area of transmissible risk in the family. CONCLUSIONS: To the authors' knowledge, the current study is the first to provide a whole-exome sequencing approach to such cases, and a framework analysis that could be applied to further understanding of the inherited risk of developing plasma cell dyscrasias. Cancer 2017;123:3701-3708. © 2017 American Cancer Society.

PEAR1 is not a major susceptibility gene for cardiovascular disease in a Flemish population.

BACKGROUND: Platelet Endothelial Aggregation Receptor 1 (PEAR1), a membrane protein highly expressed in platelets and endothelial cells, plays a role in platelet contact-induced activation, sustained platelet aggregation and endothelial function. Previous reports implicate PEAR1 rs12041331 as a variant influencing risk in patients with coronary heart disease. We investigated whether genetic variation in PEAR1 predicts cardiovascular outcome in a white population. METHODS: In 1938 participants enrolled in the Flemish Study on Environment, Genes and Health Outcomes (51.3% women; mean age 43.6 years), we genotyped 9 tagging SNPs in PEAR1, measured baseline cardiovascular risk factors, and recorded Cardiovascular disease incidence. For SNPs, we contrasted cardiovascular disease incidence of minor-allele heterozygotes and homozygotes (variant) vs. major-allele homozygotes (reference) and for haplotypes carriers vs. non-carriers. In adjusted analyses, we accounted for family clusters and baseline covariables, including sex, age, body mass index, mean arterial pressure, the total-to-HDL cholesterol ratio, smoking and drinking, antihypertensive drug treatment, and history of cardiovascular disease and diabetes mellitus. RESULTS: Over a median follow-up of 15.3 years, 238 died and 181 experienced a major cardiovascular endpoint. The multivariable-adjusted hazard ratios of eight PEAR1 SNPs, including rs12566888, ranged from 0.87 to 1.07 (P ≥0.35) and from 0.78 to 1.30 (P ≥0.15), respectively. The hazard ratios of three haplotypes with frequency ≥10% ranged from 0.93 to 1.11 (P ≥0.49) for mortality and from 0.84 to 1.03 (P ≥0.29) for a cardiovascular complications. These results were not influenced by intake of antiplatelet drugs, nonsteroidal anti-inflammatory drugs, or both (P-values for interaction ≥ 0.056). CONCLUSIONS: In a White population, we could not replicate previous reports from experimental studies or obtained in patients suggesting that PEAR1 might be a susceptibility gene for cardiovascular complications.

Novel approach identifies SNPs in SLC2A10 and KCNK9 with evidence for parent-of-origin effect on body mass index.

The phenotypic effect of some single nucleotide polymorphisms (SNPs) depends on their parental origin. We present a novel approach to detect parent-of-origin effects (POEs) in genome-wide genotype data of unrelated individuals. The method exploits increased phenotypic variance in the heterozygous genotype group relative to the homozygous groups. We applied the method to >56,000 unrelated individuals to search for POEs influencing body mass index (BMI). Six lead SNPs were carried forward for replication in five family-based studies (of ∼4,000 trios). Two SNPs replicated: the paternal rs2471083-C allele (located near the imprinted KCNK9 gene) and the paternal rs3091869-T allele (located near the SLC2A10 gene) increased BMI equally (beta = 0.11 (SD), P<0.0027) compared to the respective maternal alleles. Real-time PCR experiments of lymphoblastoid cell lines from the CEPH families showed that expression of both genes was dependent on parental origin of the SNPs alleles (P<0.01). Our scheme opens new opportunities to exploit GWAS data of unrelated individuals to identify POEs and demonstrates that they play an important role in adult obesity.

Interaction between polyphenols intake and PON1 gene variants on markers of cardiovascular disease: a nutrigenetic observational study.

BACKGROUND: Paraoxonase 1 (PON1) gene polymorphisms and polyphenols intake have been reported independently associated to lipid profile and susceptibility to atherosclerosis and cardiovascular disease. However, the interaction between these factors remains to be investigated. We performed an observational nutrigenetic study to examine whether the interaction between polyphenols and anthocyanins intake and PON1 genetic variants can modulate biomarkers of cardiovascular health in an Italian healthy population. METHODS: We recruited 443 healthy volunteers who participated in the EC funded ATHENA project (AnThocyanin and polyphenols bioactive for Health Enhancement through Nutritional Advancement). Data collection included detailed demographic, clinical, dietary, lifestyle, biochemical and genetic data. Polyphenols and anthocyanins intake was measured by 24 h dietary recall repeated three times a year in order to get seasonal variations. We tested the interaction between 18 independent tagging SNPs in PON1 gene and polyphenols intake on HDL, LDL, cholesterol, triglycerides and atherogenic index of plasma. RESULTS: Without considering the genetic background, we could not observe significant differences in the lipid profile between high and low polyphenols and anthocyanins intake. Using a nutrigenetic approach, we identified protective genotypes in four independent polymorphisms that, at Bonferroni level (p ≤ 0.0028), present a significant association with increased HDL level under high polyphenols and anthocyanins intake, compared to risk genotypes (rs854549, Beta = 4.7 per C allele; rs854552, Beta = 5.6 per C allele; rs854571, Beta = 3.92 per T allele; rs854572, Beta = 3.94 per C allele). CONCLUSIONS: We highlight the protective role of genetic variants in PON1 towards cardiovascular risk under high polyphenols and anthocyanins consumption. PON1 variants could represent novel biomarkers to stratify individuals who might benefit from targeted dietary recommendation for health promotion and strategies of preventive medicine.

A candidate gene study identifies a haplotype of CD2 as novel susceptibility factor for systemic sclerosis.

OBJECTIVES: Systemic sclerosis (SSc) is a rare autoimmune disease (AID) with a complex genetic etiology. Evidence for a shared pathogenesis across AIDs is given by the well-known pleiotropism of autoimmune genes. Recently, several unbiased approaches have identified an association between polymorphisms of the CD2 gene, and rheumatoid arthritis (RA) susceptibility. The objective of this study was to investigate whether CD2 polymorphisms are associated with SSc. METHODS: Two SNPs of CD2, rs624988 and rs798036, were genotyped in a total of 1,786 SSc patients and 2,360 healthy individuals from two European populations (France and Italy). Meta-analyses were performed to assess whether an association exists between CD2 polymorphisms or haplotypes and SSc or its main subtypes. RESULTS: The combined analyses revealed an association between the rs624988 A allele and SSc susceptibility: padj=0.023, OR=1.14 (95%CI 1.04-1.25). Single marker analysis did not reveal any association between rs798036 and SSc. Haplotype analysis identified that the A-T haplotype, previously described in RA, was associated with higher susceptibility for SSc (padj=0.029, OR=1.14, 95%CI 1.04-1.25) and with the positive anti-centromere antibody sub-group of SSc patients (padj=0.009, OR=1.19 95%CI 1.07-1.32). Genotype-mRNA expression correlations revealed that the CD2 risk haplotype was associated with decreased CD2 mRNA expression in SSc patients. CONCLUSIONS: Our study establishes CD2 as a new susceptibility factor for SSc, in a European Caucasian population, confirming the sharing of autoimmune risk factors by SSc and RA.

Association Analysis of Noncoding Variants in Neuroligins 3 and 4X Genes with Autism Spectrum Disorder in an Italian Cohort.

Since involved in synaptic transmission and located on X-chromosome, neuroligins 3 and 4X have been studied as good positional and functional candidate genes for autism spectrum disorder pathogenesis, although contradictory results have been reported. Here, we performed a case-control study to assess the association between noncoding genetic variants in NLGN3 and NLGN4X genes and autism, in an Italian cohort of 202 autistic children analyzed by high-resolution melting. The results were first compared with data from 379 European healthy controls (1000 Genomes Project) and then with those from 1061 Italian controls genotyped by Illumina single nucleotide polymorphism (SNP) array 1M-duo. Statistical evaluations were performed using Plink v1.07, with the Omnibus multiple loci approach. According to both the European and the Italian control groups, a 6-marker haplotype on NLGN4X (rs6638575(G), rs3810688(T), rs3810687(G), rs3810686(C), rs5916269(G), rs1882260(T)) was associated with autism (odd ratio = 3.58, p-value = 2.58 × 10-6 for the European controls; odds ratio = 2.42, p-value = 6.33 × 10-3 for the Italian controls). Furthermore, several haplotype blocks at 5-, 4-, 3-, and 2-, including the first 5, 4, 3, and 2 SNPs, respectively, showed a similar association with autism. We provide evidence that noncoding polymorphisms on NLGN4X may be associated to autism, suggesting the key role of NLGN4X in autism pathophysiology and in its male prevalence.

Coronary risk in relation to genetic variation in MEOX2 and TCF15 in a Flemish population.

BACKGROUND: In mice MEOX2/TCF15 heterodimers are highly expressed in heart endothelial cells and are involved in the transcriptional regulation of lipid transport. In a general population, we investigated whether genetic variation in these genes predicted coronary heart disease (CHD). RESULTS: In 2027 participants randomly recruited from a Flemish population (51.0 % women; mean age 43.6 years), we genotyped six SNPs in MEOX2 and four in TCF15. Over 15.2 years (median), CHD, myocardial infarction, coronary revascularisation and ischaemic cardiomyopathy occurred in 106, 53, 78 and 22 participants. For SNPs, we contrasted CHD risk in minor-allele heterozygotes and homozygotes (variant) vs. major-allele homozygotes (reference) and for haplotypes carriers (variant) vs. non-carriers. In multivariable-adjusted analyses with correction for multiple testing, CHD risk was associated with MEOX2 SNPs (P ≤ 0.049), but not with TCF15 SNPs (P ≥ 0.29). The MEOX2 GTCCGC haplotype (frequency 16.5 %) was associated with the sex- and age-standardised CHD incidence (5.26 vs. 3.03 events per 1000 person-years; P = 0.036); the multivariable-adjusted hazard ratio [HR] of CHD was 1.78 (95 % confidence interval, 1.25-2.56; P = 0.0054). For myocardial infarction, coronary revascularisation, and ischaemic cardiomyopathy, the corresponding HRs were 1.96 (1.16-3.31), 1.87 (1.20-2.91) and 3.16 (1.41-7.09), respectively. The MEOX2 GTCCGC haplotype significantly improved the prediction of CHD over and beyond traditional risk factors and was associated with similar population-attributable risk as smoking (18.7 % vs. 16.2 %). CONCLUSIONS: Genetic variation in MEOX2, but not TCF15, is a strong predictor of CHD. Further experimental studies should elucidate the underlying molecular mechanisms.

PEAR1 is not a human hypertension-susceptibility gene.

OBJECTIVE: Platelet endothelial aggregation receptor 1 (PEAR1) is a membrane protein involved in platelet contact-induced activation and sustained platelet aggregation. Experimental studies identified PEAR1, as a candidate gene that may be linked to the blood-pressure driven kidney injury in salt-sensitive Dahl rats. AIM: In a family-based European population study (mean age 39.7 years; 52.2% women), we searched for association of changes in blood pressure or incidence of hypertension with genetic variation in PEAR1. METHODS: Among 1973 randomly recruited people, genotyped for PEAR1, we measured blood pressure at baseline and follow-up. RESULTS: Median follow-up was 10.0 years. While accounting for family clusters and blood pressure at baseline and with adjustments applied for sex, age, body mass index, smoking and drinking, total cholesterol, and antihypertensive drug treatment, all associations of systolic and diastolic blood pressure changes with nine single nucleotide polymorphisms (SNPs) in PEAR1 were all non-significant (p ≥ 0.059). With similar adjustments, the incidence of hypertension (397 cases among 1532 participants were normotensive at baseline [25.9%]) was not related to the SNPs in PEAR1 (hazard ratios ≤ 1.09; p ≥ 0.09). CONCLUSION: Our study suggests that PEAR1 is not a hypertension susceptibility gene in humans.