Severe West Nile virus and Sars-CoV-2 infections in a patient with thymoma and anti-type I IFN antibodies.

The current study aimed to investigate determinants of severity in a previously healthy patient who experienced two life-threatening infections, from West Nile Virus and SARS-CoV2. During COVID19 hospitalization he was diagnosed with a thymoma, retrospectively identified as already present at the time of WNV infection. Heterozygosity for p.Pro554Ser in the TLR3 gene, which increases susceptibility to severe COVID-19, and homozygosity for CCR5 c.554_585del, associated to severe WNV infection, were found. Neutralizing anti-IFN-α and anti-IFN-ω auto-antibodies were detected, likely induced by the underlying thymoma and increasing susceptibility to both severe COVID-19 pneumonia and West Nile encephalitis.

Genetic determinants of type 1 diabetes in individuals with weak evidence of islet autoimmunity at disease onset.

AIMS/HYPOTHESIS: Islet autoantibodies (AAbs) are detected in >90% of individuals with clinically suspected type 1 diabetes at disease onset. A single AAb, sometimes at low titre, is often detected in some individuals, making their diagnosis uncertain. Type 1 diabetes genetic risk scores (GRS) are a useful tool for discriminating polygenic autoimmune type 1 diabetes from other types of diabetes, particularly the monogenic forms, but testing is not routinely performed in the clinic. Here, we used a type 1 diabetes GRS to screen for monogenic diabetes in individuals with weak evidence of autoimmunity, i.e. with a single AAb at disease onset. METHODS: In a pilot study, we genetically screened 142 individuals with suspected type 1 diabetes, 42 of whom were AAb-negative, 27 of whom had a single AAb (single AAb-positive) and 73 of whom had multiple AAbs (multiple AAb-positive) at disease onset. Next-generation sequencing (NGS) was performed in 41 AAb-negative participants, 26 single AAb-positive participants and 60 multiple AAb-positive participants using an analysis pipeline of more than 200 diabetes-associated genes. RESULTS: The type 1 diabetes GRS was significantly lower in AAb-negative individuals than in those with a single and multiple AAbs. Pathogenetic class 4/5 variants in MODY or monogenic diabetes genes were identified in 15/41 (36.6%) AAb-negative individuals, while class 3 variants of unknown significance were identified in 17/41 (41.5%). Residual C-peptide levels at diagnosis were higher in individuals with mutations compared to those without pathogenetic variants. Class 3 variants of unknown significance were found in 11/26 (42.3%) single AAb-positive individuals, and pathogenetic class 4/5 variants were present in 2/26 (7.7%) single AAb-positive individuals. No pathogenetic class 4/5 variants were identified in multiple AAb-positive individuals, but class 3 variants of unknown significance were identified in 19/60 (31.7%) patients. Several patients across the three groups had more than one class 3 variant. CONCLUSIONS/INTERPRETATION: These findings provide insights into the genetic makeup of patients who show weak evidence of autoimmunity at disease onset. Absence of islet AAbs or the presence of a single AAb together with a low type 1 diabetes GRS may be indicative of a monogenic form of diabetes, and use of NGS may improve the accuracy of diagnosis.

Genotype-phenotype correlation in the spectrum of frontotemporal dementia-parkinsonian syndromes and advanced diagnostic approaches.

The term frontotemporal dementia (FTD) refers to a group of progressive neurodegenerative disorders characterized mainly by atrophy of the frontal and anterior temporal lobes. Based on clinical presentation, three main clinical syndromes have traditionally been described: behavioral variant frontotemporal dementia (bvFTD), non-fluent/agrammatic primary progressive aphasia (nfPPA), and semantic variant PPA (svPPA). However, over the last 20 years, it has been recognized that cognitive phenotypes often overlap with motor phenotypes, either motor neuron diseases or parkinsonian signs and/or syndromes like progressive supranuclear palsy (PSP) and cortico-basal syndrome (CBS). Furthermore, FTD-related genes are characterized by genetic pleiotropy and can cause, even in the same family, pure motor phenotypes, findings that underlie the clinical continuum of the spectrum, which has pure cognitive and pure motor phenotypes as the extremes. The genotype-phenotype correlation of the spectrum, FTD-motor neuron disease, has been well defined and extensively investigated, while the continuum, FTD-parkinsonism, lacks a comprehensive review. In this narrative review, we describe the current knowledge about the genotype-phenotype correlation of the spectrum, FTD-parkinsonism, focusing on the phenotypes that are less frequent than bvFTD, namely nfPPA, svPPA, PSP, CBS, and cognitive-motor overlapping phenotypes (i.e. PPA + PSP). From a pathological point of view, they are characterized mainly by the presence of phosphorylated-tau inclusions, either 4 R or 3 R. The genetic correlate of the spectrum can be heterogeneous, although some variants seem to lead preferentially to specific clinical syndromes. Furthermore, we critically review the contribution of genome-wide association studies (GWAS) and next-generation sequencing (NGS) in disentangling the complex heritability of the FTD-parkinsonism spectrum and in defining the genotype-phenotype correlation of the entire clinical scenario, owing to the ability of these techniques to test multiple genes, and so to allow detailed investigations of the overlapping phenotypes. Finally, we conclude with the importance of a detailed genetic characterization and we offer to patients and families the chance to be included in future randomized clinical trials focused on autosomal dominant forms of FTLD.

Mutations in MYO9B are associated with Charcot-Marie-Tooth disease type 2 neuropathies and isolated optic atrophy.

BACKGROUND AND PURPOSE: Charcot-Marie-Tooth disease (CMT) is a heterogeneous group of disorders caused by mutations in at least 100 genes. However, approximately 60% of cases with axonal neuropathies (CMT2) still remain without a genetic diagnosis. We aimed at identifying novel disease genes responsible for CMT2. METHODS: We performed whole exome sequencing and targeted next generation sequencing panel analyses on a cohort of CMT2 families with evidence for autosomal recessive inheritance. We also performed functional studies to explore the pathogenetic role of selected variants. RESULTS: We identified rare, recessive variants in the MYO9B (myosin IX) gene in two families with CMT2. MYO9B has not yet been associated with a human disease. MYO9B is an unconventional single-headed processive myosin motor protein with signaling properties, and, consistent with this, our results indicate that a variant occurring in the MYO9B motor domain impairs protein expression level and motor activity. Interestingly, a Myo9b-null mouse has degenerating axons in sciatic nerves and optic nerves, indicating that MYO9B plays an essential role in both peripheral nervous system and central nervous system axons, respectively. The degeneration observed in the optic nerve prompted us to screen for MYO9B mutations in a cohort of patients with optic atrophy (OA). Consistent with this, we found compound heterozygous variants in one case with isolated OA. CONCLUSIONS: Novel or very rare variants in MYO9B are associated with CMT2 and isolated OA.

Functional Characterisation of the Rare SCN5A p.E1225K Variant, Segregating in a Brugada Syndrome Familial Case, in Human Cardiomyocytes from Pluripotent Stem Cells.

Brugada syndrome (BrS) is an inherited autosomal dominant cardiac channelopathy. Pathogenic rare mutations in the SCN5A gene, encoding the alpha-subunit of the voltage-dependent cardiac Na+ channel protein (Nav1.5), are identified in 20% of BrS patients, affecting the correct function of the channel. To date, even though hundreds of SCN5A variants have been associated with BrS, the underlying pathogenic mechanisms are still unclear in most cases. Therefore, the functional characterization of the SCN5A BrS rare variants still represents a major hurdle and is fundamental to confirming their pathogenic effect. Human cardiomyocytes (CMs) differentiated from pluripotent stem cells (PSCs) have been extensively demonstrated to be reliable platforms for investigating cardiac diseases, being able to recapitulate specific traits of disease, including arrhythmic events and conduction abnormalities. Based on this, in this study, we performed a functional analysis of the BrS familial rare variant NM_198056.2:c.3673G>A (NP_932173.1:p.Glu1225Lys), which has been never functionally characterized before in a cardiac-relevant context, as the human cardiomyocyte. Using a specific lentiviral vector encoding a GFP-tagged SCN5A gene carrying the specific c.3673G>A variant and CMs differentiated from control PSCs (PSC-CMs), we demonstrated an impairment of the mutated Nav1.5, thus suggesting the pathogenicity of the rare BrS detected variant. More broadly, our work supports the application of PSC-CMs for the assessment of the pathogenicity of gene variants, the identification of which is increasing exponentially due to the advances in next-generation sequencing methods and their massive use in genetic testing.

Unravelling Novel SCN5A Mutations Linked to Brugada Syndrome: Functional, Structural, and Genetic Insights.

Brugada Syndrome (BrS) is a rare inherited cardiac arrhythmia causing potentially fatal ventricular tachycardia or fibrillation, mainly occurring during rest or sleep in young individuals without heart structural issues. It increases the risk of sudden cardiac death, and its characteristic feature is an abnormal ST segment elevation on the ECG. While BrS has diverse genetic origins, a subset of cases can be conducted to mutations in the SCN5A gene, which encodes for the Nav1.5 sodium channel. Our study focused on three novel SCN5A mutations (p.A344S, p.N347K, and p.D349N) found in unrelated BrS families. Using patch clamp experiments, we found that these mutations disrupted sodium currents: p.A344S reduced current density, while p.N347K and p.D349N completely abolished it, leading to altered voltage dependence and inactivation kinetics when co-expressed with normal channels. We also explored the effects of mexiletine treatment, which can modulate ion channel function. Interestingly, the p.N347K and p.D349N mutations responded well to the treatment, rescuing the current density, while p.A344S showed a limited response. Structural analysis revealed these mutations were positioned in key regions of the channel, impacting its stability and function. This research deepens our understanding of BrS by uncovering the complex relationship between genetic mutations, ion channel behavior, and potential therapeutic interventions.

Integrated evaluation of a panel of neurochemical biomarkers to optimize diagnosis and prognosis in amyotrophic lateral sclerosis.

BACKGROUND AND PURPOSE: This study was undertaken to determine the diagnostic and prognostic value of a panel of serum biomarkers and to correlate their concentrations with several clinical parameters in a large cohort of patients with amyotrophic lateral sclerosis (ALS). METHODS: One hundred forty-three consecutive patients with ALS and a control cohort consisting of 70 patients with other neurodegenerative disorders (DEG), 70 patients with ALS mimic disorders (ALSmd), and 45 healthy controls (HC) were included. Serum neurofilament light chain (NfL), ubiquitin carboxyl-terminal hydrolase isozyme L1 (UCHL1), glial fibrillary acidic protein (GFAP), and total tau protein levels were measured using ultrasensitive single molecule array. RESULTS: NfL correlated with disease progression rate (p < 0.001) and with the measures of upper motor neuron burden (p < 0.001). NfL was higher in the ALS patients with classic and pyramidal phenotype. GFAP was raised in ALS with cognitive-behavioral impairment compared with ALS with normal cognition. NfL displayed the best diagnostic performance in discriminating ALS from HC (area under the curve [AUC] = 0.990), DEG (AUC = 0.946), and ALSmd (AUC = 0.850). UCHL1 performed well in distinguishing ALS from HC (AUC = 0.761), whereas it was not helpful in differentiating ALS from DEG and ALSmd. In multivariate analysis, NfL (p < 0.001) and UCHL1 (p = 0.038) were independent prognostic factors. Survival analysis combining NfL and UCHL1 effectively stratified patients with lower NfL levels (p < 0.001). CONCLUSIONS: NfL is a useful biomarker for the diagnosis of ALS and the strongest predictor of survival. UCHL1 is an independent prognostic factor helpful in stratifying survival in patients with low NfL levels, likely to have slowly progressive disease. GFAP reflects extramotor involvement, namely cognitive impairment or frontotemporal dementia.

Burden of Rare Variants in ALS and Axonal Hereditary Neuropathy Genes Influence Survival in ALS: Insights from a Next Generation Sequencing Study of an Italian ALS Cohort.

Although the genetic architecture of amyotrophic lateral sclerosis (ALS) is incompletely understood, recent findings suggest a complex model of inheritance in ALS, which is consistent with a multistep pathogenetic process. Therefore, the aim of our work is to further explore the architecture of ALS using targeted next generation sequencing (NGS) analysis, enriched in motor neuron diseases (MND)-associated genes which are also implicated in axonal hereditary motor neuropathy (HMN), in order to investigate if disease expression, including the progression rate, could be influenced by the combination of multiple rare gene variants. We analyzed 29 genes in an Italian cohort of 83 patients with both familial and sporadic ALS. Overall, we detected 43 rare variants in 17 different genes and found that 43.4% of the ALS patients harbored a variant in at least one of the investigated genes. Of note, 27.9% of the variants were identified in other MND- and HMN-associated genes. Moreover, multiple gene variants were identified in 17% of the patients. The burden of rare variants is associated with reduced survival and with the time to reach King stage 4, i.e., the time to reach the need for percutaneous endoscopic gastrostomy (PEG) positioning or non-invasive mechanical ventilation (NIMV) initiation, independently of known negative prognostic factors. Our data contribute to a better understanding of the molecular basis of ALS supporting the hypothesis that rare variant burden could play a role in the multistep model of disease and could exert a negative prognostic effect. Moreover, we further extend the genetic landscape of ALS to other MND-associated genes traditionally implicated in degenerative diseases of peripheral axons, such as HMN and CMT2.

ADCY10 frameshift variant leading to severe recessive asthenozoospermia and segregating with absorptive hypercalciuria.

STUDY QUESTION: Can whole exome sequencing (WES) reveal a novel pathogenic variant in asthenozoospermia in a multiplex family including multiple patients? SUMMARY ANSWER: Patients were discovered to be homozygous for a rare 2-bp deletion in the ADCY10 coding region (c.1205_1206del, rs779944215). WHAT IS KNOWN ALREADY: ADCY10 encodes for soluble adenylyl cyclase (sAC), which is the predominant adenylate cyclase in sperm. It is already established that proper sAC activity and a constant supply of cAMP are crucial to sperm motility regulation, and knockout mouse models have been reported as severely asthenozoospermic. ADCY10 is a susceptibility gene for dominant absorptive hypercalciuria (OMIM#143870); however, no ADCY10 variations have been confirmed to cause human asthenozoospermia to date. STUDY DESIGN, SIZE, DURATION: This was a retrospective genetics study of a highly consanguineous pedigree of asthenozoospermia. The subject family was recruited in Iran in 2016. PARTICIPANTS/MATERIALS, SETTING, METHODS: The two patients were diagnosed as asthenozoospermic through careful clinical investigations. Both patients, respective parents, and an unaffected brother were subjected to WES. The discovered variant was validated by Sanger sequencing and segregated with the phenotype. To confirm the pathogenicity of the variant, sperm samples from both patients, 10 normozoospermic men and 10 asthenozoospermic patients not representing the variation, were treated with a cAMP analogue dissolved in human tubal fluid medium, followed by computer-assisted sperm analysis and statistical analyses. MAIN RESULTS AND THE ROLE OF CHANCE: The discovered homozygous variant occurs at 10 amino acids upstream of the ADCY10 nucleotide binding site leading to a premature termination (p.His402Argfs*41). Treatment of the patients' sperm samples with a cell-permeable cAMP analogue resulted in a significant increase in sperm motility, indicating the pathogenic role of the variant. Moreover, absorptive hypercalciuria, segregating within the family, was also associated with the same variant following a dominant inheritance. LIMITATIONS, REASONS FOR CAUTION: Though nonsense-mediated decay is highly likely to occur in the mutated transcripts, we were not able to confirm this due to low RNA levels in mature sperm. WIDER IMPLICATIONS OF THE FINDINGS: Our finding enlarges the phenotypic spectrum associated with the ADCY10 gene, previously described as a susceptibility gene for dominant absorptive hypercalciuria. STUDY FUNDING/COMPETING INTEREST(S): This study was supported by grants from the Royan Institute, Tehran, Iran, and San Raffaele Hospital, Milan, Italy. The authors have no conflict of interest. TRIAL REGISTRATION NUMBER: N/A.

Expanding the spectrum of genes responsible for hereditary motor neuropathies.

BACKGROUND: Inherited peripheral neuropathies (IPNs) represent a broad group of genetically and clinically heterogeneous disorders, including axonal Charcot-Marie-Tooth type 2 (CMT2) and hereditary motor neuropathy (HMN). Approximately 60%-70% of cases with HMN/CMT2 still remain without a genetic diagnosis. Interestingly, mutations in HMN/CMT2 genes may also be responsible for motor neuron disorders or other neuromuscular diseases, suggesting a broad phenotypic spectrum of clinically and genetically related conditions. Thus, it is of paramount importance to identify novel causative variants in HMN/CMT2 patients to better predict clinical outcome and progression. METHODS: We designed a collaborative study for the identification of variants responsible for HMN/CMT2. We collected 15 HMN/CMT2 families with evidence for autosomal recessive inheritance, who had tested negative for mutations in 94 known IPN genes, who underwent whole-exome sequencing (WES) analyses. Candidate genes identified by WES were sequenced in an additional cohort of 167 familial or sporadic HMN/CMT2 patients using next-generation sequencing (NGS) panel analysis. RESULTS: Bioinformatic analyses led to the identification of novel or very rare variants in genes, which have not been previously associated with HMN/CMT2 (ARHGEF28, KBTBD13, AGRN and GNE); in genes previously associated with HMN/CMT2 but in combination with different clinical phenotypes (VRK1 and PNKP), and in the SIGMAR1 gene, which has been linked to HMN/CMT2 in only a few cases. These findings were further validated by Sanger sequencing, segregation analyses and functional studies. CONCLUSIONS: These results demonstrate the broad spectrum of clinical phenotypes that can be associated with a specific disease gene, as well as the complexity of the pathogenesis of neuromuscular disorders.

Efficacy of lentivirus-mediated gene therapy in an Omenn syndrome recombination-activating gene 2 mouse model is not hindered by inflammation and immune dysregulation.

BACKGROUND: Omenn syndrome (OS) is a rare severe combined immunodeficiency associated with autoimmunity and caused by defects in lymphoid-specific V(D)J recombination. Most patients carry hypomorphic mutations in recombination-activating gene (RAG) 1 or 2. Hematopoietic stem cell transplantation is the standard treatment; however, gene therapy (GT) might represent a valid alternative, especially for patients lacking a matched donor. OBJECTIVE: We sought to determine the efficacy of lentiviral vector (LV)-mediated GT in the murine model of OS (Rag2R229Q/R229Q) in correcting immunodeficiency and autoimmunity. METHODS: Lineage-negative cells from mice with OS were transduced with an LV encoding the human RAG2 gene and injected into irradiated recipients with OS. Control mice underwent transplantation with wild-type or OS-untransduced lineage-negative cells. Immunophenotyping, T-dependent and T-independent antigen challenge, immune spectratyping, autoantibody detection, and detailed tissue immunohistochemical analyses were performed. RESULTS: LV-mediated GT allowed immunologic reconstitution, although it was suboptimal compared with that seen in wild-type bone marrow (BM)-transplanted OS mice in peripheral blood and hematopoietic organs, such as the BM, thymus, and spleen. We observed in vivo variability in the efficacy of GT correlating with the levels of transduction achieved. Immunoglobulin levels and T-cell repertoire normalized, and gene-corrected mice responded properly to challenges in vivo. Autoimmune manifestations, such as skin infiltration and autoantibodies, dramatically improved in GT mice with a vector copy number/genome higher than 1 in the BM and 2 in the thymus. CONCLUSIONS: Our data show that LV-mediated GT for patients with OS significantly ameliorates the immunodeficiency, even in an inflammatory environment.

Novel JAG1 Deletion Variant in Patient with Atypical Alagille Syndrome.

Alagille syndrome (AGS) is an autosomal-dominant disorder characterized by various degrees of abnormalities in the liver, heart, eyes, vertebrae, kidneys, face, vasculature, skeleton, and pancreas. This case report describes a newborn child exhibiting a congenital neural tube defect and peculiar craniofacial appearance characterized by a prominent forehead, deep-set eyes, bulbous nasal tip, and subtle upper lip. Just a few hours after birth, congenital heart disease was suspected for cyanosis and confirmed by heart evaluation. In particular, echocardiography indicated pulmonary atresia with ventricular septal defect with severe hypoplasia of the pulmonary branches (1.5 mm), large patent ductus arteriosus and several major aortopulmonary collateral arteries. Due to the association of peculiar craniofacial appearance and congenital heart disease, a form of Alagille syndrome was suspected. In addition, on the fifth day after birth, the patient developed jaundice, had acholic stools, and high levels of conjugated bilirubin and gamma-glutamyltransferase (GGT) were detected in the blood. Genetic testing revealed the novel variant c.802del in a single copy of the JAG1 gene. No variants in the NOTCH2 gene were detected. To the best of our knowledge, this is the first clinical description of a congenital neural tube defect in a molecularly confirmed Alagille patient. This work demonstrates a novel pathogenic heterozygous JAG1 mutation is associated with an atypical form of Alagille syndrome, suggesting an increased risk for neural tube defects compared to other Alagille patients.

TBK1 mutations in Italian patients with amyotrophic lateral sclerosis: genetic and functional characterisation.

BACKGROUND: TANK-binding kinase 1 (TBK1) gene has been recently identified as a causative gene of amyotrophic lateral sclerosis (ALS). METHODS: We sequenced the TBK1 gene in a cohort of 154 Italian patients with ALS with unclear genetic aetiology. We subsequently assessed the pathogenic potential of novel identified TBK1 variants using functional in vitro studies: expression, targeting and activity were evaluated in patient-derived fibroblasts and in cells transfected with mutated-TBK1 plasmids. RESULTS: We identified novel genomic TBK1 variants including two loss-of-function (LoF) (p.Leu59Phefs*16 and c.358+5G>A), two missense (p.Asp118Asn and p.Ile397Thr) and one intronic variant (c.1644-5_1644-2delAATA), in addition to two previously reported pathogenetic missense variants (p.Lys291Glu and p.Arg357Gln). Functional studies in patient-derived fibroblasts revealed that the c.358+5G>A causes aberrant pre-mRNA processing leading TBK1 haploinsufficiency. Biochemical studies in cellular models showed that the truncating variant p.Leu59Phefs*16 abolishes TBK1 protein expression, whereas the p.Asp118Asn variant severely impairs TBK1 phosphorylation activity. Conversely, the p.Ile397Thr variant displayed enhanced phosphorylation activity, whose biological relevance is not clear. CONCLUSION: The observed frequency of TBK1 LoF variants was 1.3% (2/154), increasing up to 3.2% (5/154) by taking into account also the functional missense variants that we were able to classify as potentially pathogenic, supporting the relevance of TBK1 in the Italian population with ALS.

Combined early treatment in hemiplegic attacks related to CACNA1A encephalopathy with brain oedema: Blocking the cascade?

Introduction Variants in the CACNA1A gene on chromosome 19p13 result in a spectrum of neurological phenotypes ranging from familial or sporadic hemiplegic migraine to congenital or progressive encephalopathies. Patients with CACNA1A variants often show acute attacks with ataxia or hemiplegia till coma, sometimes related to unilateral brain oedema. No guidelines for the medical management of these attacks are available since treatment is empiric, and many cases do not respond to common antimigraine drugs. Case description We report on the emergency personalized treatment protocol used in an 11 year-old girl with CACNA1A-related encephalopathy for the management of acute attacks of headache, hemiconvulsions and hemiplegia with coma. Discussion Combined corticosteroid pulses and hypertonic solution led to a reduction in severity and duration of acute attacks when administered in the early stages, characterized by migraine, seizure, fever, vomiting and impairment of consciousness associated to hemispheric slowing on the EEG.

Clinical Pregenetic Screening for Stroke Monogenic Diseases: Results From Lombardia GENS Registry.

BACKGROUND AND PURPOSE: Lombardia GENS is a multicentre prospective study aimed at diagnosing 5 single-gene disorders associated with stroke (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, Fabry disease, MELAS [mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes], hereditary cerebral amyloid angiopathy, and Marfan syndrome) by applying diagnostic algorithms specific for each clinically suspected disease METHODS: We enrolled a consecutive series of patients with ischemic or hemorrhagic stroke or transient ischemic attack admitted in stroke units in the Lombardia region participating in the project. Patients were defined as probable when presenting with stroke or transient ischemic attack of unknown etiopathogenic causes, or in the presence of <3 conventional vascular risk factors or young age at onset, or positive familial history or of specific clinical features. Patients fulfilling diagnostic algorithms specific for each monogenic disease (suspected) were referred for genetic analysis. RESULTS: In 209 patients (57.4±14.7 years), the application of the disease-specific algorithm identified 227 patients with possible monogenic disease. Genetic testing identified pathogenic mutations in 7% of these cases. Familial history of stroke was the only significant specific feature that distinguished mutated patients from nonmutated ones. The presence of cerebrovascular risk factors did not exclude a genetic disease. CONCLUSIONS: In patients prescreened using a clinical algorithm for monogenic disorders, we identified monogenic causes of events in 7% of patients in comparison to the 1% to 5% prevalence reported in previous series.

Possible role of fructosamine 3-kinase genotyping for the management of diabetic patients.

Diabetes mellitus is a global pandemic and continues to increase in numbers and significance. Several pathogenic processes are involved in the development of such disease and these mechanisms could be influenced by genetic, epigenetic and environmental factors. Non-enzymatic glycation reactions of proteins have been strongly related to pathogenesis of chronic diabetic complications. The identification of fructosamine 3-kinase (FN3K), an enzyme involved in protein deglycation, a new form of protein repair, is of great interest. FN3K phosphorylates fructosamines on the third carbon of their sugar moiety, making them unstable and causing them to detach from proteins, suggesting a protective role of this enzyme. Moreover, the variability in FN3K activity has been associated with some polymorphisms in the FN3K gene. Here we argue about genetic studies and evidence of FN3K involvement in diabetes, together with results of our analysis of the FN3K gene on a Caucasian cohort of diabetic patients. Present knowledge suggests that FN3K could act in concert with other molecular mechanisms and may impact on gene expression and activity of other enzymes involved in deglycation process.

The E1015K variant in the synprint region of the CaV2.1 channel alters channel function and is associated with different migraine phenotypes.

Mutations in the CACNA1A gene, which encodes the pore-forming α1A subunit of the CaV2.1 voltage-gated calcium channel, cause a number of human neurologic diseases including familial hemiplegic migraine. We have analyzed the functional impact of the E1015K amino acid substitution located in the "synprint" domain of the α1A subunit. This variant was identified in two families with hemiplegic migraine and in one patient with migraine with aura. The wild type (WT) and the E1015K forms of the GFP-tagged α1A subunit were expressed in cultured hippocampal neurons and HEK cells to understand the role of the variant in the transport activity and physiology of CaV2.1. The E1015K variant does not alter CaV2.1 protein expression, and its transport to the cell surface and synaptic terminals is similar to that observed for WT channels. Electrophysiological data demonstrated that E1015K channels have increased current density and significantly altered inactivation properties compared with WT. Furthermore, the SNARE proteins syntaxin 1A and SNAP-25 were unable to modulate voltage-dependent inactivation of E1015K channels. Overall, our findings describe a genetic variant in the synprint site of the CaV2.1 channel which is characterized by a gain-of-function and associated with both hemiplegic migraine and migraine with aura in patients.

A novel SPAST gene splicing variant (c.1617-2A>C) in a heterozygous carrier with hereditary spastic paraplegia.

Hereditary spastic paraplegia (HSP) is a group of genetically heterogenous neurodegenerative disorders characterized by progressive spasticity and weakness of lower limbs. We report a novel splicing variant (c.1617-2A>C) of the SPAST gene in a heterozygous carrier from an Italian family with autosomal dominant HSP. The case study describes a pure form of spastic paraparesis with the cardinal clinical features of SPG4. The novel variant affects a canonical splice site and is likely to disrupt RNA splicing. We conclude that the c.1617-2A>C substitution is a null variant, which could be classified as pathogenic; its penetrance should be further investigated.

Unveiling the SOD1-mediated ALS phenotype: insights from a comprehensive meta-analysis.

BACKGROUND AND OBJECTIVES: Amyotrophic lateral sclerosis associated with mutations in SOD1 (SOD1-ALS) might be susceptible to specific treatment. The aim of the study is to outline the clinical features of SOD1-ALS patients by comparing them to patients without ALS major gene variants and patients with variants in other major ALS genes. Defining SOD1-ALS phenotype may assist clinicians in identifying patients who should be prioritized for genetic testing. METHODS: We performed an extensive literature research including original studies which reported the clinical features of SOD1-ALS and at least one of the following patient groups: C9ORF72 hexanucleotide repeat expansion (C9-ALS), TARDBP (TARDBP-ALS), FUS (FUS-ALS) or patients without a positive test for a major-ALS gene (N-ALS). A random effects meta-analytic model was applied to clinical data extracted encompassing sex, site and age of onset. To reconstruct individual patient survival data, the published Kaplan-Meier curves were digitized. Data were measured as odds ratio (OR) or standardized mean difference (SMD) as appropriate. Median survival was compared between groups. RESULTS: Twenty studies met the inclusion criteria. We identified 721 SOD1-ALS, 470 C9-ALS, 183 TARDBP-ALS, 113 FUS-ALS and 2824 N-ALS. SOD1-ALS showed a higher rate of spinal onset compared with N-ALS and C9-ALS (OR = 4.85, 95% CI = 3.04-7.76; OR = 10.47, 95% CI = 4.32-27.87) and an earlier onset compared with N-ALS (SMD = - 0.45, 95% CI = - 0.72 to - 0.18). SOD1-ALS had a similar survival compared with N-ALS (p = 0.14), a longer survival compared with C9-ALS (p < 0.01) and FUS-ALS (p = 0.019) and a shorter survival compared with TARDBP-ALS (p < 0.01). DISCUSSION: This study indicates the presence of a specific SOD1-ALS phenotype. Insights in SOD1-ALS clinical features are important in genetic counseling, disease prognosis and support patients' stratification in clinical trials.