DNA methylation epi-signature is associated with two molecularly and phenotypically distinct clinical subtypes of Phelan-McDermid syndrome.

BACKGROUND: Phelan-McDermid syndrome is characterized by a range of neurodevelopmental phenotypes with incomplete penetrance and variable expressivity. It is caused by a variable size and breakpoint microdeletions in the distal long arm of chromosome 22, referred to as 22q13.3 deletion syndrome, including the SHANK3 gene. Genetic defects in a growing number of neurodevelopmental genes have been shown to cause genome-wide disruptions in epigenomic profiles referred to as epi-signatures in affected individuals. RESULTS: In this study we assessed genome-wide DNA methylation profiles in a cohort of 22 individuals with Phelan-McDermid syndrome, including 11 individuals with large (2 to 5.8 Mb) 22q13.3 deletions, 10 with small deletions (< 1 Mb) or intragenic variants in SHANK3 and one mosaic case. We describe a novel genome-wide DNA methylation epi-signature in a subset of individuals with Phelan-McDermid syndrome. CONCLUSION: We identified the critical region including the BRD1 gene as responsible for the Phelan-McDermid syndrome epi-signature. Metabolomic profiles of individuals with the DNA methylation epi-signature showed significantly different metabolomic profiles indicating evidence of two molecularly and phenotypically distinct clinical subtypes of Phelan-McDermid syndrome.

A genome-wide DNA methylation signature for SETD1B-related syndrome.

SETD1B is a component of a histone methyltransferase complex that specifically methylates Lys-4 of histone H3 (H3K4) and is responsible for the epigenetic control of chromatin structure and gene expression. De novo microdeletions encompassing this gene as well as de novo missense mutations were previously linked to syndromic intellectual disability (ID). Here, we identify a specific hypermethylation signature associated with loss of function mutations in the SETD1B gene which may be used as an epigenetic marker supporting the diagnosis of syndromic SETD1B-related diseases. We demonstrate the clinical utility of this unique epi-signature by reclassifying previously identified SETD1B VUS (variant of uncertain significance) in two patients.

Does a familial subtype of complex regional pain syndrome exist? Results of a systematic review.

Background and Objective: Complex regional pain syndrome (CRPS) is a chronic condition characterized by severe regional pain, allodynia, hyperalgesia, and functional impairment. The aim of this systematic review is to investigate whether a familial subtype of CRPS (fCRPS) exists and to determine whether people with fCRPS have specific characteristics. Methods: Databases CINAHL, Medline, PsycINFO, and PubMed were searched with no date limitation. Quality of reporting was assessed using the Scottish Intercollegiate Guidelines Network scale and the Joanna Briggs Institute's checklists. Results: Eight studies were included. Family relationships were defined as any immediate (i.e., parents or siblings) or blood relatives. A combination of participants with known or unknown causes for CRPS was recruited. The studies in this review support the potential for the existence of fCRPS, although this included less than 25% of those affected. People with potential fCRPS showed more severe symptoms, more sites involved, a higher percentage of spontaneous onset, and earlier age at onset. An elevated sibling recurrence risk ratio of 5.6 (95% confidence interval [CI], 3.0 to 9.8) was reported for people under 50. None of the studies established a pattern of heritability. Therefore, the most likely explanation for heritability would be a multifactorial model in which cumulative and interactive Gene × Environment effects may be involved. Conclusions: This systematic review supports the potential for the existence of fCRPS; however, all identified studies used uncontrolled case reports, case series, and case-control designs that cannot provide evidence of causation. Further studies are required to reveal the heritability and genetic structure of fCRPS.

Contexte et objectifs: Le syndrome de douleur régionale complexe (SDRC) est une maladie chronique qui se caractérise par de fortes douleurs régionales, une allodynie, une hyperalgésie et une déficience fonctionnelle. Le but de cette revue systématique était de vérifier s'il existe un sous-type familial de SDRC (SDRCf) et de déterminer si les personnes atteintes de SDRCf présentent des caractéristiques particulières.Méthodes: Des recherches ont été effectuées dans les bases de données CINAHL, Medline, PsychINFO et PubMed, sans limite de date. La qualité des rapports a été évaluée à l'aide de l'échelle du Scottish Intercollegiate Guidelines Network et des listes de vérification de l'Institut Joanna Briggs.Résultats: Huit études ont été incluses. Les relations familiales ont été définies comme toutes les relations immédiates (i.e. parents, frères ou soeurs), ou les parents consanguins. Une combinaison de participants pour lesquels les causes du SDRC étaient connues et inconnues ont été recrutés. Les études ayant fait partie de cette revue vont dans le sens de la possible existence d'un SDRCf, bien que cette constatation touchait moins de 25 % des personnes affectées. Les personnes souffrant d'un possible SDRCf présentaient des symptômes plus graves, un plus grand nombre de régions touchées, un pourcentage plus élevé de déclenchements spontanés et le déclenchement de la maladie à un plus jeune âge. Un rapport relatif de récurrence élevé, se situant à 5,6 (95 % IC, 3,0 à 9,8) chez les frères et soeurs, a été rapporté pour les personnes de moins de 50 ans. Aucune des études n'établissait de modèle d'héritabilité. L'explication la plus plausible pour l'héritabilité serait donc un modèle mutifactoriel dans lequel les effets cumulatifs des gènes et de l'environnement pourraient interagir.Conclusions: Les conclusions de cette revue systémaique vont dans le sens de l'existence possible du SDRCf; toutefois, toutes les études répertoriées ont eu recours à des devis non contrôlés comme des rapports de cas, des séries de cas et des études cas-témoins qui ne peuvent pas prouver le lien de causalité. D'autres études sont nécesaires pour révéler l'héritabilité et la structure génétique du SDRCf.

Endothelin-1 regulation is entangled in a complex web of epigenetic mechanisms in diabetes.

Endothelial cells (ECs) are primary targets of glucose-induced tissue damage. As a result of hyperglycemia, endothelin-1 (ET-1) is upregulated in organs affected by chronic diabetic complications. The objective of the present study was to identify novel transcriptional mechanisms that influence ET-1 regulation in diabetes. We carried out the investigation in microvascular ECs using multiple approaches. ECs were incubated with 5 mM glucose (NG) or 25 mM glucose (HG) and analyses for DNA methylation, histone methylation, or long non-coding RNA- mediated regulation of ET-1 mRNA were then performed. DNA methylation array analyses demonstrated the presence of hypomethylation in the proximal promoter and 5' UTR/first exon regions of EDN1 following HG culture. Further, globally blocking DNA methylation or histone methylation significantly increased ET-1 mRNA expressions in both NG and HG-treated HRECs. While, knocking down the pathogenetic lncRNAs ANRIL, MALAT1, and ZFAS1 subsequently prevented the glucose-induced upregulation of ET-1 transcripts. Based on our past and present findings, we present a novel paradigm that reveals a complex web of epigenetic mechanisms regulating glucose-induced transcription of ET-1. Improving our understanding of such processes may lead to better targeted therapies.

Metabolomic analysis of human plasma reveals that arginine is depleted in knee osteoarthritis patients.

OBJECTIVE: To identify novel biomarker(s) for knee osteoarthritis (OA) using a metabolomics approach. METHOD: We utilized a two-stage case-control study design. Plasma samples were collected from knee OA patients and healthy controls after 8-h fasting and metabolically profiled using a targeted metabolomics assay kit. Linear regression was used to identify novel metabolic markers for OA. Receiver operating characteristic (ROC) analysis was used to examine diagnostic values. Gene expression analysis was performed on human cartilage to explore the potential mechanism for the novel OA marker(s). RESULTS: Sixty-four knee OA patients and 45 controls were included in the discovery stage and 72 knee OA patients and 76 age and sex matched controls were included in the validation stage. We identified and confirmed six metabolites that were significantly associated with knee OA, of which arginine was the most significant metabolite (P < 3.5 × 10(-13)) with knee OA patients having on average 69 µM lower than that in controls. ROC analysis showed that arginine had the greatest diagnostic value with area under the curve (AUC) of 0.984. The optimal cutoff of arginine concentration was 57 µM with 98.3% sensitivity and 89% specificity. The depletion of arginine in OA patients was most likely due to the over activity of arginine to ornithine pathway, leading to imbalance between cartilage repair and degradation. CONCLUSION: Arginine is significantly depleted in refractory knee OA patients. Further studies within a longitudinal setting are required to examine whether arginine can predict early OA changes.

The genetic background of Southern Iranian couples before marriage.

Genetic service for couples plays an increasingly important role in diagnosis and risk management. This study investigated the status of consanguinity and the medical genetic history (effectiveness and coverage of medical genetic services) in couples residing in a city in southern Iran. We questioned couples who were referred to Behbahan Marital Counseling Center, Behbahan, Iran, during the period from January to November 2014, to obtain information on consanguinity, disease history, and previous referral to a medical genetics center. For the collected data was obtained descriptive statistics with STATA 11.0 software. A total of 500 couples were questioned. Mean age was 24.8 ± 5.2 years. Almost one quarter (23.4%) of the couples were consanguineous. Consanguinity was almost twice as common in rural areas as in urban areas (33.9 vs. 19.2%, p = 0.001). Only a few couples (~3.0%) had ever been referred for genetic counseling. The main reason for previous genetic counseling was consanguinity (85.7%). The majority of the participants (96.3%) had never been tested for any genetic conditions. Our findings suggest that only a small proportion of couples in Khuzestan Province, Iran (Behbahan City) were receiving adequate genetics care. This may reflect the limited accessibility of such services, and inadequate awareness and education among the care providers.