Truncating NFKB1 variants cause combined NLRP3 inflammasome activation and type I interferon signaling and predispose to necrotizing fasciitis.

In monogenic autoinflammatory diseases, mutations in genes regulating innate immune responses often lead to uncontrolled activation of inflammasome pathways or the type I interferon (IFN-I) response. We describe a mechanism of autoinflammation potentially predisposing patients to life-threatening necrotizing soft tissue inflammation. Six unrelated families are identified in which affected members present with necrotizing fasciitis or severe soft tissue inflammations. Exome sequencing reveals truncating monoallelic loss-of-function variants of nuclear factor κ light-chain enhancer of activated B cells (NFKB1) in affected patients. In patients' macrophages and in NFKB1-variant-bearing THP-1 cells, activation increases both interleukin (IL)-1ß secretion and IFN-I signaling. Truncation of NF-κB1 impairs autophagy, accompanied by the accumulation of reactive oxygen species and reduced degradation of inflammasome receptor nucleotide-binding oligomerization domain, leucine-rich repeat-containing protein 3 (NLRP3), and Toll/IL-1 receptor domain-containing adaptor protein inducing IFN-ß (TRIF), thus leading to combined excessive inflammasome and IFN-I activity. Many of the patients respond to anti-inflammatory treatment, and targeting IL-1ß and/or IFN-I signaling could represent a therapeutic approach for these patients.

Wiskott-Aldrich Syndrome: A study on 577 patients defining the genotype as a predictive biomarker for disease severity.

WAS is a multifaceted monogenic disorder with a broad disease spectrum and variable disease severity and a variety of treatment options including allogeneic hematopoietic stem cell transplantation (HSCT) and gene therapy (GT). No reliable biomarker exists to predict disease course and outcome for individual patients. A total of 577 patients with a WAS variant from 26 countries and a median follow-up of 8.9 years (0.3-71.1), totaling 6118 patient-years, were included in this international retrospective study. Overall survival (OS) of the cohort (censored at HSCT or GT) was 82% (95% CI 78-87) at 15 years and 70% (61-80) at 30 years of age. The type of variant was predictive of outcome: patients with a missense variant in exons 1 or 2 or with the intronic hotspot variant c.559+5G>A (class I variants) had a 15-year OS of 93% (89-98) and a 30-year OS of 91% (86-97), compared to 71% (62-81) and 48% (34-68) in patients with any other variant (class II; p<0.0001). The cumulative incidence rates of disease-related complications such as severe bleeding (p=0.007), life-threatening infection (p<0.0001), and autoimmunity (p=0.004) occurred significantly later in patients with a class I variant. The cumulative incidence of malignancy (p=0.6) was not different between classes I and II. This study represents the largest cohort of WAS patients studied so far. It confirms the spectrum of disease severity and quantifies the risk for specific disease-related complications. The class of variant is a biomarker to predict the outcome for WAS patients.

Gasdermin D drives focal Crystalline Thrombotic Microangiopathy by accelerating Immunothrombosis and Necroinflammation.

Thrombotic microangiopathy (TMA) is characterized by immunothrombosis and life-threatening organ failure, but the precise underlying mechanism driving its pathogenesis remains elusive. In this study, we hypothesized that gasdermin D (GSDMD), a pore-forming protein serving as the final downstream effector of pyroptosis/interleukin (IL)-1pathway, contributes to TMA and its consequences by amplifying neutrophil maturation and subsequent necrosis. Using a murine model of focal crystalline TMA, we found that Gsdmd-deficiency ameliorated immunothrombosis, acute tissue injury and failure. Gsdmd-/- mice exhibited a decrease in mature IL-1, as well as in neutrophil maturation, 2 integrin activation, and recruitment to TMA lesions, where they formed reduced neutrophil extracellular traps both in arteries and interstitial tissue. The GSDMD inhibitor disulfiram dose-dependently suppressed human neutrophil pyroptosis in response to cholesterol crystals. Experiments with GSDMD-deficient human induced pluripotent stem cell-derived neutrophils confirmed the involvement of GSDMD in neutrophil 2 integrin activation, maturation as well as pyroptosis. Both prophylactic and therapeutic administration of disulfiram protected mice from focal TMA, acute tissue injury and failure. Our data identify GSDMD as a key mediator of focal crystalline TMA and its consequences: ischemic tissue infarction and organ failure. GSDMD could potentially serve as a therapeutic target for systemic forms of TMA.

[Participation in children's hospitals: approaches to participatory formats for paediatric patients]. / Teilhabe im Kinderkrankenhaus: Formate zur Verwirklichung des Rechts auf Partizipation von jungen Patientinnen und Patienten.

Based on the UN Convention on the Rights of the Child, children and young people have the right to participate in all matters and decisions that affect them. This applies in particular when they are patients in a children's hospital. In the international context, established formats for the participation of young patients regarding health issues already exist, for example "Children's Councils" or "Young Person's Advisory Groups". In Germany, such approaches are still mostly lacking. It thus remains important to develop suitable formats that enable meaningful and effective participation of young patients in the health system. These formats must be chosen in such a way that they can realistically be implemented in clinical settings as well as in pediatric research, and that they can be sustained in the long term. In order to strengthen the consideration of children's rights in the health system, the advancement of such participatory formats as well as their sustainable implementation and evaluation are desirable.

Generation of complex bone marrow organoids from human induced pluripotent stem cells.

The human bone marrow (BM) niche sustains hematopoiesis throughout life. We present a method for generating complex BM-like organoids (BMOs) from human induced pluripotent stem cells (iPSCs). BMOs consist of key cell types that self-organize into spatially defined three-dimensional structures mimicking cellular, structural and molecular characteristics of the hematopoietic microenvironment. Functional properties of BMOs include the presence of an in vivo-like vascular network, the presence of multipotent mesenchymal stem/progenitor cells, the support of neutrophil differentiation and responsiveness to inflammatory stimuli. Single-cell RNA sequencing revealed a heterocellular composition including the presence of a hematopoietic stem/progenitor (HSPC) cluster expressing genes of fetal HSCs. BMO-derived HSPCs also exhibited lymphoid potential and a subset demonstrated transient engraftment potential upon xenotransplantation in mice. We show that the BMOs could enable the modeling of hematopoietic developmental aspects and inborn errors of hematopoiesis, as shown for human VPS45 deficiency. Thus, iPSC-derived BMOs serve as a physiologically relevant in vitro model of the human BM microenvironment to study hematopoietic development and BM diseases.

Transcatheter management of pure native aortic valve regurgitation in patients with left ventricular assist device.

OBJECTIVES: Aortic valve regurgitation (AR) frequently complicates the clinical course after left ventricular assist device (LVAD) implantation. Transcatheter aortic valve implantation (TAVI) has emerged as an alternative to surgical aortic valve replacement (SAVR) in this cohort with a mostly high surgical risk profile. The unique challenges in LVAD patients, such as presence of non-calcified aortic valves and annular dilatation, raise concerns about device migration and paravalvular leakage (PVL) leading to missing device success. This study evaluates procedural outcomes and survival rates in LVAD patients who underwent TAVI, emphasizing strategies to enhance device success. METHODS: Between January 2017 and April 2023, 27 LVAD patients with clinically significant AR underwent elective or urgent TAVI at our centre. Primary end-points were procedural success rates, without the need for a second transcatheter heart valve (THV) and postprocedural AR/PVL. Secondary outcomes included survival rates and adverse events. RESULTS: Among the cohort, 14.8% received AR-dedicated TAVI devices, with none requiring a second THV. There was no intraprocedural AR, and 1 patient (25%) had AR > 'trace' at discharge. Additionally, 25.9% underwent device landing zone (DLZ) pre-stenting with a standard TAVI device, all without needing a second THV. There was no intraprocedural AR, and none to trace AR at discharge. Among the 59.3% receiving standard TAVI devices, 37.5% required a second THV. In this subgroup, intraprocedural AR > 'trace' occurred in 12.5%, decreasing to 6.25% at discharge. In-hospital mortality was 3.7%, and median follow-up survival was 388 days (interquartile range 208-1167 days). CONCLUSIONS: TAVI yields promising procedural outcomes and early survival rates in LVAD patients with AR. Tailored TAVI devices and pre-stenting techniques enhance procedural success. Continued research into these strategies is essential to optimize outcomes in this complex patient cohort.

Clinical and functional spectrum of RAC2-related immunodeficiency.

ABSTRACT: Mutations in the small Rho-family guanosine triphosphate hydrolase RAC2, critical for actin cytoskeleton remodeling and intracellular signal transduction, are associated with neonatal severe combined immunodeficiency (SCID), infantile neutrophilic disorder resembling leukocyte adhesion deficiency (LAD), and later-onset combined immune deficiency (CID). We investigated 54 patients (23 previously reported) from 37 families yielding 15 novel RAC2 missense mutations, including one present only in homozygosity. Data were collected from referring physicians and literature reports with updated clinical information. Patients were grouped by presentation: neonatal SCID (n = 5), infantile LAD-like disease (n = 5), or CID (n = 44). Disease correlated to RAC2 activity: constitutively active RAS-like mutations caused neonatal SCID, dominant-negative mutations caused LAD-like disease, whereas dominant-activating mutations caused CID. Significant T- and B-lymphopenia with low immunoglobulins were seen in most patients; myeloid abnormalities included neutropenia, altered oxidative burst, impaired neutrophil migration, and visible neutrophil macropinosomes. Among 42 patients with CID with clinical data, upper and lower respiratory infections and viral infections were common. Twenty-three distinct RAC2 mutations, including 15 novel variants, were identified. Using heterologous expression systems, we assessed downstream effector functions including superoxide production, p21-activated kinase 1 binding, AKT activation, and protein stability. Confocal microscopy showed altered actin assembly evidenced by membrane ruffling and macropinosomes. Altered protein localization and aggregation were observed. All tested RAC2 mutant proteins exhibited aberrant function; no single assay was sufficient to determine functional consequence. Most mutants produced elevated superoxide; mutations unable to support superoxide formation were associated with bacterial infections. RAC2 mutations cause a spectrum of immune dysfunction, ranging from early onset SCID to later-onset combined immunodeficiencies depending on RAC2 activity. This trial was registered at www.clinicaltrials.gov as #NCT00001355 and #NCT00001467.

Brain expression profiles of two SCN1A antisense RNAs in children and adolescents with epilepsy.

Objective: Heterozygous mutations within the voltage-gated sodium channel α subunit (SCN1A) are responsible for the majority of cases of Dravet syndrome (DS), a severe developmental and epileptic encephalopathy. Development of novel therapeutic approaches is mandatory in order to directly target the molecular consequences of the genetic defect. The aim of the present study was to investigate whether cis-acting long non-coding RNAs (lncRNAs) of SCN1A are expressed in brain specimens of children and adolescent with epilepsy as these molecules comprise possible targets for precision-based therapy approaches. Methods: We investigated SCN1A mRNA expression and expression of two SCN1A related antisense RNAs in brain tissues in different age groups of pediatric non-Dravet patients who underwent surgery for drug resistant epilepsy. The effect of different antisense oligonucleotides (ASOs) directed against SCN1A specific antisense RNAs on SCN1A expression was tested. Results: The SCN1A related antisense RNAs SCN1A-dsAS (downstream antisense, RefSeq identifier: NR_110598) and SCN1A-usAS (upstream AS, SCN1A-AS, RefSeq identifier: NR_110260) were widely expressed in the brain of pediatric patients. Expression patterns revealed a negative correlation of SCN1A-dsAS and a positive correlation of lncRNA SCN1A-usAS with SCN1A mRNA expression. Transfection of SK-N-AS cells with an ASO targeted against SCN1A-dsAS was associated with a significant enhancement of SCN1A mRNA expression and reduction in SCN1A-dsAS transcripts. Conclusion: These findings support the role of SCN1A-dsAS in the suppression of SCN1A mRNA generation. Considering the haploinsufficiency in genetic SCN1A related DS, SCN1A-dsAS is an interesting target candidate for the development of ASOs (AntagoNATs) based precision medicine therapeutic approaches aiming to enhance SCN1A expression in DS.

Multisensory integration deficits in Schizophrenia and Autism evidenced in behaviour but not event related potentials.

The process of integrating information from different sensory channels, known as multisensory integration (MSI) was assessed in two disorders, Autism Spectrum Disorder (ASD) and Schizophrenia (SCZ). 32 healthy controls (HC), 35 SCZ patients, and 23 ASD patients performed an audiovisual (AV) synchronous target detection task while reaction time (RT) and scalp recorded electrophysiological (EEG) activity were measured. MSI in the AV condition resulted in faster and less variable RTs compared to the unimodal conditions. Using our novel bootstrap method, MSI gain was observed in 78 % of HC, 26 % of ASD, and 48 % of SCZ patients. At the neural level, MSI in the AV condition resulted in larger amplitude of sensory evoked responses and cognitive P3 response compared to the corresponding unimodal conditions. These neural effects of MSI were not related to the behavioural MSI gain identified at the individual level and could not explain the deficits in behavioural MSI of patient groups. In conclusion, a robust MSI gain deficit in RT was observed in both patient groups that was not reflected in early perceptual and cognitive electro-cortical responses, suggesting that behavioural MSI deficits in ASD and SCZ may arise at late processing stages such as response selection.

Disrupted degradative sorting of TLR7 is associated with human lupus.

Hyperactive TLR7 signaling has long been appreciated as driver of autoimmune disease in mouse models. Recently, gain-of-function mutations in TLR7 were identified as a monogenic cause of human lupus. TLR7 is an intracellular transmembrane receptor, sensing RNA breakdown products within late endosomes. Here, we show that endosome dysfunction leads to unrestricted TLR7 signaling and is associated with human lupus. The late endosomal BORC complex together with the small GTPase Arl8b controls intracellular TLR7 levels by regulating receptor turnover. This requires a direct interaction between the TLR7-associated trafficking factor Unc93b1 and Arl8b. We identified an UNC93B1 mutation in a patient with childhood-onset lupus, which results in reduced BORC interaction and endosomal TLR7 accumulation. Therefore, a failure to control TLR7 turnover is sufficient to break immunological tolerance to nucleic acids. Our results highlight the importance of an intact endomembrane system in preventing pathological TLR7 signaling and autoimmune disease.

A Novel Biallelic LCK Variant Resulting in Profound T-Cell Immune Deficiency and Review of the Literature.

Lymphocyte-specific protein tyrosine kinase (LCK) is an SRC-family kinase critical for initiation and propagation of T-cell antigen receptor (TCR) signaling through phosphorylation of TCR-associated CD3 chains and recruited downstream molecules. Until now, only one case of profound T-cell immune deficiency with complete LCK deficiency [1] caused by a biallelic missense mutation (c.1022T>C, p.L341P) and three cases of incomplete LCK deficiency [2] caused by a biallelic splice site mutation (c.188-2A>G) have been described. Additionally, deregulated LCK expression has been associated with genetically undefined immune deficiencies and hematological malignancies. Here, we describe the second case of complete LCK deficiency in a 6-month-old girl born to consanguineous parents presenting with profound T-cell immune deficiency. Whole exome sequencing (WES) revealed a novel pathogenic biallelic missense mutation in LCK (c.1393T>C, p.C465R), which led to the absence of LCK protein expression and phosphorylation, and a consecutive decrease in proximal TCR signaling. Loss of conventional CD4+ and CD8+ αßT-cells and homeostatic T-cell expansion was accompanied by increased γδT-cell and Treg percentages. Surface CD4 and CD8 co-receptor expression was reduced in the patient T-cells, while the heterozygous mother had impaired CD4 and CD8 surface expression to a lesser extent. We conclude that complete LCK deficiency is characterized by profound T-cell immune deficiency, reduced CD4 and CD8 surface expression, and a characteristic TCR signaling disorder. CD4 and CD8 surface expression may be of value for early detection of mono- and/or biallelic LCK deficiency.

CARD9 deficiency with allergic bronchopulmonary aspergillosis (ABPA)-like presentation: a case report.

PURPOSE: We present a patient with CARD9 deficiency and allergic bronchopulmonary aspergillosis (ABPA)-like presentation. METHODS: Following medical history taking and routine laboratory investigations, an inborn error of immunity was suspected, and the responsible variant was identified using Whole Exome Sequencing and confirmed by Sanger sequencing. RESULTS: A 14-year-old Iranian female presented with a history of chest pain, productive cough, dyspnea, malaise, and recurrent fever. Imaging by computed tomography (CT scan), chest X-ray (CXR), bronchoscopy, transbronchial lung biopsy (TBLB), and histopathology findings led to a diagnosis of ABPA-like presentation. The genetic study showed an autosomal recessive homozygous mutation in the CARD9 gene. Clinical remission was achieved following the administration of voriconazole, which was continued as prophylaxis. CONCLUSIONS: This is the first-time report of a patient with inherited CARD9 deficiency and ABPA-like presentation due to Aspergillus Terrus. This study paves the way to elucidate immunological mechanisms underlying CARD9 deficiency and aspergillosis.

Efficacy and Safety of Anti-Tumor Necrosis Factor Alpha in Very Early Onset Inflammatory Bowel Disease.

BACKGROUND: Very early onset inflammatory bowel disease (VEOIBD) is defined as disease onset in patients younger than 6 years. Challenges in treatment of VEOIBD include lack of approved therapies and increased incidence of monogenic immunodeficiencies. We report on patterns of anti-TNF use, efficacy, and safety in a large cohort of patients with VEOIBD. METHODS: Very early onset inflammatory bowel disease patients receiving care at a single center were prospectively enrolled in a data registry and biorepository starting in 2012. Whole exome sequencing was available to all patients. Clinical data including IBD medication use and response were extracted from the medical record. We examined antitumor necrosis factor (anti-TNF) cumulative exposure and time to failure and evaluated the effect of covariates on anti-TNF failure using Cox proportional hazard regression. RESULTS: In this cohort of 216 VEOIBD patients with median 5.8-year follow-up, 116 (53.7%) were TNF-exposed. Sixty-two TNF-exposed patients (53.4%) received their first dose at younger than 6 years. Cumulative exposure to anti-TNF was 23.6% at 1 year, 38.4% at 3 years, and 43.4% at 5 years after diagnosis. Cumulative exposure was greater in patients with Crohn's disease (P = .0004) and in those diagnosed in 2012 or later (P < .0001). Tumor necrosis factor failure occurred in 50.9% of those exposed. Features predictive of anti-TNF failure included ulcerative colitis/IBD-unclassified (hazard ratio, 1.94; P = .03), stricturing (hazard ratio, 2.20; P = .04), and younger age at diagnosis (hazard ratio, 1.25; P = .01). Adverse events occurred in 22.6% of infliximab-exposed and 14.3% of adalimumab-exposed. CONCLUSIONS: Efficacy and safety of anti-TNFs in VEOIBD is comparable to what has previously been reported in older patients.

Half of VEOIBD patients followed for a median 5.8 years used anti-TNF. Anti-TNF failure occurred in half of those exposed. Stricturing, UC/IBD-U, and younger age at diagnosis were predictors of failure. Adverse events were similar to those reported in older patients.

Precision medicine in monogenic inflammatory bowel disease: proposed mIBD REPORT standards.

Owing to advances in genomics that enable differentiation of molecular aetiologies, patients with monogenic inflammatory bowel disease (mIBD) potentially have access to genotype-guided precision medicine. In this Expert Recommendation, we review the therapeutic research landscape of mIBD, the reported response to therapies, the medication-related risks and systematic bias in reporting. The mIBD field is characterized by the absence of randomized controlled trials and is dominated by retrospective observational data based on case series and case reports. More than 25 off-label therapeutics (including small-molecule inhibitors and biologics) as well as cellular therapies (including haematopoietic stem cell transplantation and gene therapy) have been reported. Heterogeneous reporting of outcomes impedes the generation of robust therapeutic evidence as the basis for clinical decision making in mIBD. We discuss therapeutic goals in mIBD and recommend standardized reporting (mIBD REPORT (monogenic Inflammatory Bowel Disease Report Extended Phenotype and Outcome of Treatments) standards) to stratify patients according to a genetic diagnosis and phenotype, to assess treatment effects and to record safety signals. Implementation of these pragmatic standards should help clinicians to assess the therapy responses of individual patients in clinical practice and improve comparability between observational retrospective studies and controlled prospective trials, supporting future meta-analysis.

C-terminal variants in CDC42 drive type I interferon-dependent autoinflammation in NOCARH syndrome reversible by ruxolitinib.

C-terminal variants in CDC42 encoding cell division control protein 42 homolog underlie neonatal-onset cytopenia, autoinflammation, rash, and hemophagocytic lymphohistiocytosis (NOCARH). Pyrin inflammasome hyperactivation has been shown to contribute to disease pathophysiology. However, mortality of NOCARH patients remains high despite inflammasome-focused treatments. Here, we demonstrate in four NOCARH patients from three families that cell-intrinsic activation of type I interferon (IFN) is a previously unrecognized driver of autoinflammation in NOCARH. Our data show that aberrant innate immune activation is caused by sensing of cytosolic nucleic acids released from mitochondria, which exhibit disturbances in integrity and dynamics due to CDC42 dysfunction. In one of our patients, treatment with the Janus kinase inhibitor ruxolitinib led to complete remission, indicating that inhibition of type I IFN signaling may have an important role in the management of autoinflammation in patients with NOCARH.

Excellent outcome of stem cell transplantation for sickle cell disease.

Many sickle cell disease (SCD) patients lack matched family donors (MFD) or matched unrelated donors (MUD), implying haploidentical donors (MMFD) as a logical donor choice. We used a reduced toxicity protocol for all donor types. We included 31 patients (2-22 years) with MFD (n = 15), MMFD (10), or MUD (6) HSCT and conditioning with alemtuzumab/ATG, thiotepa, fludarabine and treosulfan, and post-transplant cyclophosphamide for MMFD. After the initial six patients, treosulfan was replaced by targeted busulfan (AUC 65-75 ng*h/ml). After a median follow-up of 26 months (6-123), all patients are alive and off immunosuppression. Two MMFD patients experienced secondary graft failure with recurrence of SCD, both after treosulfan conditioning. Neither acute GVHD ≥ °III nor moderate/severe chronic GVHD was observed. The disease-free, severe GVHD-free survival was 100%, 100%, and 80% in the MFD, MUD, and MMFD groups, respectively (p = 0.106). There was a higher rate of virus reactivation in MMFD (100%) and MUD (83%) compared to MFD (40%; p = 0.005), but not of viral disease (20% vs 33% vs 13%; p = 0.576). Six patients had treosulfan-based conditioning, two of whom experienced graft failure (33%), compared to 0/25 (0%) after busulfan-based conditioning (p = 0.032). Donor chimerism was ≥ 80% in 28/31 patients (90%) at last follow-up. Reduced toxicity myeloablative conditioning resulted in excellent overall survival, negligible GVHD, and low toxicity among all donor groups in pediatric and young adult patients with SCD.

Transcatheter Aortic Valve Replacement for Isolated Aortic Regurgitation Using a New Self-Expanding TAVR System.

BACKGROUND: Patients with severe aortic regurgitation (AR) are often not considered for surgery because of increased surgical risk. Because of unique anatomical characteristics among patients with AR, interventional treatment options are limited, and implantation results are inconsistent compared with those among patients with aortic stenosis. OBJECTIVES: The authors describe the initial commercial experience of the first Conformité Européenne-marked transfemoral transcatheter aortic valve replacement system (JenaValve Trilogy [JV]) for the treatment of patients with AR. METHODS: This multicenter registry included 58 consecutive patients from 6 centers across Germany. Transcatheter aortic valve replacement was performed with the JV system for isolated severe and symptomatic AR. Patient characteristics, primary implantation outcomes, and valve performance up to 30 days were analyzed using Valve Academic Research Consortium 3 definitions. RESULTS: The mean patient age was 76.5 ± 9 years, with a mean Society of Thoracic Surgeons score of 4.2% ± 4.3%. Device success was achieved in 98% of patients. The mean gradient was 4.3 ± 1.6 mm Hg, and no moderate or severe paravalvular regurgitation occurred. No conversion to open heart surgery or valve embolization was reported. There were no major vascular complications or bleeding events. The rate of new permanent pacemaker implantation was 19.6%. At 30 days, 92% of the patients were in NYHA functional class I or II, and the 30-day mortality rate was 1.7%. CONCLUSIONS: Treatment of patients with severe symptomatic AR using the transfemoral JV system is safe and effective. Given its favorable hemodynamic performance and low complication rates, this system may offer a new treatment option for patients with AR not suitable for surgery.

Movement initiation and preparation in subjects with schizophrenia - The amplitude of the readiness potential as a biological marker for negative symptom severity.

OBJECTIVE: Despite extensive research, the etiology of negative symptoms is not well understood. Preliminary findings are linking motor disturbances to negative symptom severity. We aimed to further the understanding to what extent motor movement preparation influences negative symptom severity. METHODS: In a cohort of 31 subjects with schizophrenia and 20 control subjects we recorded the readiness potential amplitude over Cz during spontaneous movements of the right and left thumb. We further assessed negative and positive symptom severity (scale for the assessment of negative and positive symptoms) as well as neurological soft signs (NSS). RESULTS: In subjects with schizophrenia the severity of negative symptoms was best predicted by the readiness potential amplitude and the NSS subdomain motor coordination. The correlation between deficits in motor coordination and negative symptom severity was partially mediated by the readiness potential amplitude in subjects with schizophrenia. CONCLUSIONS: Deficits in motor processing are linked to negative symptom severity in schizophrenia. The readiness potential may represent a biological marker of these basal deficits. In combination with the assessment of NSS, the readiness potential may be a marker of the course of negative symptom severity and help clarifying interdependencies between (pre)frontal networks for action initiation and coordination, as well as negative symptoms.