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BackgroundPathogenic variants of GNB5 encoding the β5 subunit of the guanine nucleotide-binding protein cause IDDCA syndrome, an autosomal recessive neurodevelopmental disorder associated with cognitive disability and cardiac arrhythmia, particularly severe bradycardia.MethodsWe used echocardiography and telemetric ECG recordings to investigate consequences of Gnb5 loss in mouse.ResultsWe delineated a key role of Gnb5 in heart sinus conduction and showed that Gnb5-inhibitory signalling is essential for parasympathetic control of heart rate (HR) and maintenance of the sympathovagal balance. Gnb5−/− mice were smaller and had a smaller heart than Gnb5+/+ and Gnb5+/−, but exhibited better cardiac function. Lower autonomic nervous system modulation through diminished parasympathetic control and greater sympathetic regulation resulted in a higher baseline HR in Gnb5−/− mice. In contrast, Gnb5−/− mice exhibited profound bradycardia on treatment with carbachol, while sympathetic modulation of the cardiac stimulation was not altered. Concordantly, transcriptome study pinpointed altered expression of genes involved in cardiac muscle contractility in atria and ventricles of knocked-out mice. Homozygous Gnb5 loss resulted in significantly higher frequencies of sinus arrhythmias. Moreover, we described 13 affected individuals, increasing the IDDCA cohort to 44 patients.ConclusionsOur data demonstrate that loss of negative regulation of the inhibitory G-protein signalling causes HR perturbations in Gnb5−/− mice, an effect mainly driven by impaired parasympathetic activity. We anticipate that unravelling the mechanism of Gnb5 signalling in the autonomic control of the heart will pave the way for future drug screening.

Tay-Sachs disease (TSD) is a rare autosomalrecessive genetic disorder characterized by progressive destruction of nerve cells in the brain and spinal cord. It is caused by genetic variations in the HEXA gene leading to a deficiency of β hexosaminidase A (HEXA) isoenzyme activity. This study aimed to identify causative gene variants in 3 unrelated consanguineous families presented with TSD from Pakistan and Morocco.Detailed clinical investigations were carried out on probands in 3 unrelated consanguineous families of Pakistani and Moroccan origin. Targeted gene sequencing and Whole Exome Sequencing (WES) were performed for variant identification. Candidate variants were checked for co-segregation with the phenotype using Sanger sequencing. Public databases including ExAC, GnomAD, dbSNP and the 1,000 Genome Project were searched to determine frequencies of the alleles. Conservation of the missense variants was ensured by aligning orthologous protein sequences from diverse vertebrate species.We report on 3 children presented with Tay-Sachs Disease. The β hexosaminidaseA enzyme activity was reduced in the Pakistani patient in one of the pedigrees. Genetic testing revealed 2 novel homozygous variants (p.Asp386Alafs*13 and p.Trp266Gly) in the gene HEXA in Pakistani and Moroccan patients respectively.The third family of Pakistani origin revealed a previously reported variant (p.Tyr427Ilefs*5) in HEXA. p.Tyr427Ilefs*5 is the most commonly occurring pathogenic variationin Ashkenazi but was not reported in Pakistani population.Our study further expands the ethnic and mutational spectrum of Tay-Sachs disease emphasizing the usefulness of WES as a powerful diagnostic tool where enzymatic activity is not performed for Tay-Sachs disease. The study recommends targeted screening for these mutations (p.Tyr427Ilefs5) for cost effective testing of TSD patients. Further, the study would assist in carrier testing and prenatal diagnosis of the affected families.Das Tay-Sachs-Syndrom ist eine seltene, autosomal-rezessiv vererbte Krankheit, die durch eine progressive Zerstörung von Nervenzellen im Gehirn und Rückenmark gekennzeichnet ist. Ursächlich liegen der Erkrankung genetische Variationen im HEXA-Gen zugrunde, die zu einem Mangel an β-Hexosaminidase A (HEXA)-Isoenzymaktivität führen. Ziel der vorliegenden Studie war es, die Genvarianten in drei nicht miteinander in Verbindung stehenden konsanguinen Familien aus Pakistan und Marokko zu identifizieren, die für das Auftreten von Tay-Sachs-Syndrom in diesen Familien verantwortlich waren.In drei nicht miteinander in Verbindung stehenden konsanguinen Familien, die aus Pakistan und Marokko stammten, wurden Studienteilnehmer einer genauen klinischen Diagnostik unterzogen. Die Identifizierung der Genvarianten erfolgte mittels gezielter Gensequenzierung und Sequenzierung des Gesamtexoms (WES, Whole Exome Sequencing). Für die Prüfung der Kandidatenvarianten auf Co-Segregation mit dem Phänotyp wurde die Sanger-Sequenzierung verwendet. Um die Häufigkeit der Allele zu bestimmen, wurde eine Suche in öffentlichen Datenbanken, darunter ExAC, GnomAD, dbSNP und das 1.000-Genom-Projekt, durchgeführt. Der Erhalt der Missense-Varianten wurde mittels Abgleich orthologer Proteinsequenzen von verschiedenen Wirbeltierarten sichergestellt.Wir berichten über drei Kinder mit Tay-Sachs-Syndrom. In einem der Stammbäume fand sich bei dem pakistanischen Patienten eine verminderte Aktivität des Enzyms β-Hexosaminidase A. Bei der genetischen Testung wurden zwei neuartige homozygote Varianten (p.Asp386Alafs * 13 und p.Trp266Gly) im Gen HEXA bei dem pakistanischen bzw. marokkanischen Patienten gefunden. Bei der dritten Familie mit pakistanischer Abstammung fand sich eine zuvor bereits berichtete Variante (p.Tyr427Ilefs * 5) im HEXA-Gen. Bei Ashkenazi-Juden ist p. Tyr427Ilefs * 5 die häufigste pathogene Variante, doch wurde sie zuvor nicht in der pakistanischen Bevölkerung beschrieben.Unsere Studie erweitert das Spektrum der ethnische Gruppen, in denen Fälle von Tay-Sachs-Syndrom beschrieben wurden, und der zugrundeliegenden Mutationen. Sie macht deutlich, dass die Gesamt-Exom-Sequenzierung (WES) als leistungsstarkes diagnostisches Verfahren in Fällen nützlich ist, bei denen keine Bestimmung der enzymatische Aktivität in Bezug auf das Tay-Sachs-Syndrom durchgeführt wird. Für die kosteneffektive Untersuchung von Patienten mit Tay-Sachs-Syndrom wird ein gezieltes Screening auf diese Mutationen (p. Tyr427Ilefs5) empfohlen. Außerdem würde die Untersuchung die Anlageträgertestung und Pränataldiagnostik in den betroffenen Familien unterstützen.

The SLC25A22 (Solute Carrier Family 25, Member 22) gene encodes for a mitochondrial glutamate/H+ symporter and is involved in the mitochondrial transport of metabolites across the mitochondrial membrane. We hereby report a 12-year-old girl presenting with early-onset epileptic encephalopathy, hypotonia, and global developmental delay. Whole exome sequencing identified a novel homozygous missense mutation in SLC25A22 gene (c.97A>G; p.Lys33Glu), as the likely cause of the disease. The phenotype of our patient and EEG recordings do not completely overlap with the phenotypes previously described, leading to a new and more complex form of disease associated with SLC25A22 variants, characterized by dyskinetic movements and oculogyric crisis.

Hereditary lung diseases can affect the airways, parenchyma and vasculature of the lung. Such diseases comprehend simple monogenic disorders such as Kartagener syndrome and α1-antitrypsin deficiency, in which mutations of critical genes are sufficient to induce well‐defined disease phenotypes. A major comprehension of the genetic basis of pulmonary diseases has produced new investigations into their underlying pathophysiology and contributed sometimes to clarify on more frequent sporadic forms. The presence of these structural abnormalities of the respiratory tract can be fatal, so that the identification of causative genes has allowed prenatal diagnosis for many diseases giving a greater hope of survival thanks to a more adequate and prompt management.

Aminoacyl-tRNA synthetases (ARSs) are ubiquitous, ancient enzymes that charge amino acids to cognate tRNA molecules, the essential first step of protein translation. Here, we describe 32 individuals from 21 families, presenting with microcephaly, neurodevelopmental delay, seizures, peripheral neuropathy, and ataxia, with de novo heterozygous and bi-allelic mutations in asparaginyl-tRNA synthetase (NARS1). We demonstrate a reduction in NARS1 mRNA expression as well as in NARS1 enzyme levels and activity in both individual fibroblasts and induced neural progenitor cells (iNPCs). Molecular modeling of the recessive c.1633C>T (p.Arg545Cys) variant shows weaker spatial positioning and tRNA selectivity. We conclude that de novo and bi-allelic mutations in NARS1 are a significant cause of neurodevelopmental disease, where the mechanism for de novo variants could be toxic gain-of-function and for recessive variants, partial loss-of-function.

Background Most studies relative to Y chromosome abnormalities are focused on the sexual developmental disorders. Recently, a few studies suggest that some genes located on Y chromosome may be related to different neurodevelopment disorders. Case presentation We report a child with sexual developmental disorder associated with a peculiar phenotype characterized by severe language impairment and autistic behaviour associated with a mosaicism [45,X(11)/46,XY(89)] and a partial deletion of the short and long arm of Y chromosome (del Yp11.31q11.23) that also involves the loss of both PCDH11Y and NLGN4Y genes. To our knowledge no study has ever reported the occurrence of the lack of both PCDH11Y and NLGN4Y located in the Y chromosome in the same patient. Conclusions We hypothesized a functional complementary role of PCDH11Y and NLGN4Y within formation/maturation of the cerebral cortex. The impairment of early language development may be mainly related to the lack of PCDH11Y that underlies the early language network development and the later appearance of the autistic behaviour may be mainly related to deficit of inhibitory glicinergic neurotransmission NLGN4Y-linked.

Human immunodeficiency virus-1 (HIV-1) is characterised by a vast genetic diversity classified into distinct phylogenetic strains and recombinant forms. We describe the HIV-1 molecular epidemiology and evolution of 129 consecutive HIV-1 positive migrants living in Milan (northern Italy). Polymerase gene sequences of 116 HIV-1 subtype-B positive patients were aligned with HIV-1 reference sequences (https://www.ncbi.nlm.nih.gov/) by using MAFFT alignment and edited by using Bioedit software. A maximum likelihood (ML) phylogenetic tree was performed by MEGA7 and was visualised by using FigTree v1.4.3. Of 129 migrants, 35 were born in Europe (28 in Eastern Europe), 70 in the Americas (67 in South America), 15 in Africa and nine in Asia; 76.4% were men who have sex with men (MSM). The serotype HIV-1-B prevailed (89.9%), followed by -C, -F1, -D and -A. Compared with 116 HIV-B patients, the 13 with HIV-non-B showed lower Nadir of CD4+ cell/mmc (P= 0.043), more frequently had sub Saharan origin (38.5vs.1.72%,P= 0.0001) and less frequently were MSM (40vs.74.5%,P= 0.02). The ML phylogenetic tree of the 116 HIV-1 subtype-B positive patients showed 13 statistically supported nodes (bootstrap > 70%). Most of the sequences included in these nodes have been isolated from male patients from the Americas and the most common risk factor was MSM. The low number of HIV-1 non-B subtype patients did not allow to perform this analysis. These results suggest a shift of HIV-1 prevention projects' focus and a continuous monitoring of HIV-1 molecular epidemiology among entry populations. Prevention efforts based on HIV molecular epidemiology may improve public health surveillance setting.

Wiedemann-Steiner syndrome (WDSTS) is a rare genetic disorder including developmental delay/intellectual disability (DD/ID), hypertrichosis cubiti, short stature, and distinctive facial features, caused by mutation in KMT2A gene, which encodes a histone methyltransferase (H3K4) that regulates chromatin-mediated transcription. Different neurodevelopmental phenotypes have been described within the WDSTS spectrum, including a peculiar Autism Spectrum Disorder (ASDs) subtype in some affected individuals. Here, we report a 9-year-old Caucasian male found by next-generation panel sequencing to carry a novel heterozygous de novo KMT2A frameshift variant (NM_001197104.2:c.4433delG; p. Arg1478LeufsTer108). This boy presented a WDSTS phenotype associated with broad neurodevelopmental features, including an unusual speech difficulty (i.e., palilalia), and brain imaging studies revealed an array of cortical anomalies (e.g., frontal simplified gyration, focal frontal cortical dysplasia). These clinical and radiological observations expand the known WDSTS-related neurodevelopmental phenotypes and further strengthen the important role of KMT2A in brain function and cortical development.

Selective IgA deficiency (SIgAD) is the most common humoral primary immunodeficiency. Long-term follow-up data in large cohort of pediatric patients are scarce. We report on a single-center cohort of 184 pediatric patients affected with selective IgA deficiency and describe the characteristics at diagnosis and during follow-up. Respiratory infections were the most common clinical finding leading to the initial diagnosis (62%). Positive family history for antibody deficiencies (selective IgA deficiency, common variable immunodeficiency) led to SIgAD diagnosis in 16% of cases. During follow-up, while the incidence of respiratory infections was not particularly high, gastrointestinal symptoms were reported in 27% of patients. Allergic manifestations were found in 23% at diagnosis and an additional 16% of patients during follow-up, leading to a prevalence of atopy of 39% among SIgAD patients. Autoimmune manifestations, excluding celiac disease, were found in 9% of affected patients during follow-up. Celiac disease was found in a high prevalence (14%). Increase of serum IgA levels to partial deficiency (9%) and normal serum levels for age (4%) was observed during follow-up. A small percentage of patients (2%) progressed to common variable immunodeficiency (CVID). In conclusion, this is the first study to describe a large single-center pediatric cohort of patients affected with SIgAD, revealing that overall most patients do well with regard to infections. Many develop CD, at a rate much higher than the general population. A few normalize their IgA levels. A few progress to CVID. Thus, careful follow-up is suggested to diagnose and treat potential complications earlier for avoiding potential morbidities.

Wieacker-Wolff syndrome (WWS) is an X-linked Arthrogryposis Multiplex Congenita (AMC) disorder associated with broad neurodevelopmental impairment. The genetic basis of WWS lies in hemizygous pathogenic variants in ZC4H2, encoding a C4H2 type zinc-finger nuclear factor abundantly expressed in the developing human brain. The main clinical features described in WWS families carrying ZC4H2 pathogenic variants encompass having a short stature, microcephaly, birth respiratory distress, arthrogryposis, hypotonia, distal muscle weakness, and broad neurodevelopmental delay. We hereby report a Sicilian family with a boy clinically diagnosed with WWS and genetically investigated with exome sequencing (ES), leading to the identification of a c.593G>A (p. R198Q) hemizygous pathogenic variant in the ZC4H2 gene. During the first year of life, the onset of central hypoadrenalism led to recurrent hypoglycemic events, which likely contributed to seizure susceptibility. Also, muscle biopsy studies confirmed a pathology of the muscle tissue and revealed peculiar abnormalities of the neuromuscular junction. In conclusion, we expand the phenotypic spectrum of the WWS-related neurodevelopmental disorders and discuss the role of ZC4H2 in the context of the potential neuroendocrinological and neuromuscular features associated with this condition.

This study analysed the impact of PNPLA3 variants on liver histology of 168 HIV/hepatitis C virus (HCV)-coinfected patients who were naïve for HCV treatment. A athologist unaware of the patients' condition graded liver fibrosis and necroinflammation (Ishak) and steatosis (Kleiner). Patients were tested for PNPLA3 variants and genotyped for the PNPLA3 rs738409 C to G variant underlying the I148M substitution. All were hepatitis B surface antigen negative and stated no alcohol abuse. The mean age was 40.6 (37.6-44.1) years, 72.6% were males, 42% had HCV genotype 3, 38.9% HCV genotype 1 and 79.2% were receiving highly active antiretroviral therapy. The 79 patients with the PNPLA3 p.148I/M or M/M variants more frequently showed severe steatosis (score 3-4) than the 89 with PNPLA3 p.148I/I (43% vs. 24.7%, p 0.001), whereas no difference was observed in the degree of necroinflammation or fibrosis. Compared with 112 patients with lower scores, 56 with severe steatosis showed higher body mass index (p 0.03), higher rate of HCV genotype 3 (55.6% vs. 35.2%, p 0.01), PNPLA3 p.148I/M or M/M (60.7% vs. 39.3%, p 0.01) and lower CD4(+) cells/mm(3) (514.00 (390.5-673.0) vs. 500.00 (399.0-627.0); p 0.002). At multivariate analysis, body mass index (p 0.01), HCV genotype 3 (p 0.006), CD4(+) cell count (p 0.005) and PNPLA3 p.148I/M or M/M variants (p 0.01) were found to be independent predictors of severe liver steatosis. The PNPLA3 p.148 I/M or M/M variants and CD4(+) cell count were the only independent predictors of severe steatosis in patients with HCV non-3 genotypes. This is the first study to show that among HIV/HCV-coinfected patients the PNPLA3 p.148I/M or M/M variant have substantially less impact on steatosis for those with HCV genotype 3 than non-genotype 3.

Neurofibromatosis type 1 (NF1) is a proteiform genetic condition caused by pathogenic variants in NF1 and characterized by a heterogeneous phenotypic presentation. Relevant genotype–phenotype correlations have recently emerged, but only few pertinent studies are available. We retrospectively reviewed clinical, instrumental, and genetic data from a cohort of 583 individuals meeting at least 1 diagnostic National Institutes of Health (NIH) criterion for NF1. Of these, 365 subjects fulfilled ≥2 NIH criteria, including 235 pediatric patients. Genetic testing was performed through cDNA-based sequencing, Next Generation Sequencing (NGS), and Multiplex Ligation-dependent Probe Amplification (MLPA). Uni- and multivariate statistical analysis was used to investigate genotype–phenotype correlations. Among patients fulfilling ≥ 2 NIH criteria, causative single nucleotide variants (SNVs) and copy number variations (CNVs) were detected in 267/365 (73.2%) and 20/365 (5.5%) cases. Missense variants negatively correlated with neurofibromas (p = 0.005). Skeletal abnormalities were associated with whole gene deletions (p = 0.05) and frameshift variants (p = 0.006). The c.3721C&gt, T, p.(R1241*) variant positively correlated with structural brain alterations (p = 0.031), whereas Lisch nodules (p = 0.05) and endocrinological disorders (p = 0.043) were associated with the c.6855C&gt, A, p.(Y2285*) variant. We identified novel NF1 genotype–phenotype correlations and provided an overview of known associations, supporting their potential relevance in the implementation of patient management.

We identified nine patients from four unrelated families harboring three biallelic variants in SCN1B (NM_001037.5: c.136C>T; p.[Arg46Cys], c.178C>T; p.[Arg60Cys], and c.472G>A; p.[Val158Met]). All subjects presented with early infantile epileptic encephalopathy 52 (EIEE52), a rare, severe developmental and epileptic encephalopathy featuring infantile onset refractory seizures followed by developmental stagnation or regression. Because SCN1B influences neuronal excitability through modulation of voltage-gated sodium (Na(V)) channel function, we examined the effects of human SCN1B(R46C) (β1(R46C)), SCN1B(R60C) (β1(R60C)), and SCN1B(V158M) (β1(V158M)) on the three predominant brain Na(V) channel subtypes Na(V)1.1 (SCN1A), Na(V)1.2 (SCN2A), and Na(V)1.6 (SCN8A). We observed a shift toward more depolarizing potentials of conductance–voltage relationships (Na(V)1.2/β1(R46C), Na(V)1.2/β1(R60C), Na(V)1.6/β1(R46C), Na(V)1.6/β1(R60C), and Na(V)1.6/β1(V158M)) and channel availability (Na(V)1.1/β1(R46C), Na(V)1.1/β1(V158M), Na(V)1.2/β1(R46C), Na(V)1.2/β1(R60C), and Na(V)1.6/β1(V158M)), and detected a slower recovery from fast inactivation for Na(V)1.1/β1(V158M). Combined with modeling data indicating perturbation-induced structural changes in β1, these results suggest that the SCN1B variants reported here can disrupt normal Na(V) channel function in the brain, which may contribute to EIEE52.

Microphthalmia, anophthalmia, and coloboma (MAC) are a group of congenital eye anomalies that can affect one or both eyes. Patients can present one or a combination of these ocular abnormalities in the so called “MAC spectrum”. The KIF17 gene encodes the kinesin-like protein Kif17, a microtubule-based, ATP-dependent, motor protein that is pivotal for outer segment development and disc morphogenesis in different animal models, including mice and zebrafish. In this report, we describe a Sicilian family with two siblings affected with congenital coloboma, microphthalmia, and a mild delay of motor developmental milestones. Genomic DNA from the siblings and their unaffected parents was sequenced with a clinical exome that revealed compound heterozygous variants in the KIF17 gene (NM_020816.4: c.1255C &gt, T (p.Arg419Trp), c.2554C &gt, T (p.Arg852Cys)) segregating with the MAC spectrum phenotype of the two affected siblings. Variants were inherited from the healthy mother and father, are present at a very low-frequency in genomic population databases, and are predicted to be deleterious in silico. Our report indicates the potential co-segregation of these biallelic KIF17 variants with microphthalmia and coloboma, highlighting a potential conserved role of this gene in eye development across different species.

A rapidly expanding catalog of neurogenetic disorders has encouraged a diagnostic shift towards early clinical whole exome sequencing (WES). Adult primary mitochondrial diseases (PMDs) frequently exhibit neurological manifestations that overlap with other nervous system disorders. However, mitochondrial DNA (mtDNA) is not routinely analyzed in standard clinical WES bioinformatic pipelines. We reanalyzed 11,424 exomes, enriched with neurological diseases, for pathogenic mtDNA variants. Twenty-four different mtDNA mutations were detected in 64 exomes, 11 of which were considered disease causing based on the associated clinical phenotypes. These findings highlight the diagnostic uplifts gained by analyzing mtDNA from WES data in neurological diseases. ANN NEUROL 2021;89:1240-1247.

Background Recurrent respiratory infections (RRIs) are defined by the presence of at least one of the following criteria: (i) > 6 annual respiratory infections (RIs); (ii) > 1 monthly RIs involving the upper airways from September to April; (iii) > 3 annual RIs involving the lower airways represent a very common health problem in the first years of life. We conducted a multi-centre, prospective, single-open study to assess the efficacy and the safety of Streptococcus salivarius 24SMBc and Streptococcus oralis 89a in the prevention of upper respiratory tract infections (URTIs) in children. Methods Ninety-one children (M:F = 47:44, mean age 7.4 ± 2.3 years) with RRIs were enrolled in the study between September and November 2018. At baseline, children received Streptococcus salivarius 24SMBc and Streptococcus oralis 89a as 2 puffs for nostril twice/day for 7 days/months. The treatment lasted for 3 consecutive months. Efficacy was expressed in terms of absence or presence of fever, cough, bronchospasm, rhinorrhea and otalgia, at 1 month (T1), and 3 (T3) months. Safety and tolerability of the probiotic were evaluated on the basis of the number and type of adverse events (AEs) recorded during the treatment. Results Children treated with Streptococcus salivarius 24SMBc and Streptococcus oralis 89a showed a significant decrease of symptoms including episodes of fever, cough, bronchospasm, rhinorrhea, and otalgia (p p p > 0.05). Conducting a subgroup analysis according to the age, it has been reported that children aged 1–3 years old showed an improvement in all symptoms, however, they become statistically significant only at the end of the 3 months of treatment (p p Conclusions Our findings suggest that Streptococcus salivarius 24SMBc and Streptococcus oralis 89a treatment is safe and seems to be effective on short-term in the treatment of RRIs. Studies involving a longer observation period are necessary to establish the real efficacy of the product for the treatment of pediatric patients affected by RRIs.

Mutations in the WWOX gene cause a broad range of ultra-rare neurodevelopmental and brain degenerative disorders, associated with a high likelihood of premature death in animal models as well as in humans. The encoded Wwox protein is a WW domain-containing oxidoreductase that participates in crucial biological processes including tumor suppression, cell growth/differentiation and regulation of steroid metabolism, while its role in neural development is less understood. We analyzed the exomes of a family affected with multiple pre- and postnatal anomalies, including cerebellar vermis hypoplasia, severe neurodevelopmental impairment and refractory epilepsy, and identified a segregating homozygous WWOX mutation leading to a premature stop codon. Abnormal cerebral cortex development due to a defective architecture of granular and molecular cell layers was found in the developing brain of a WWOX-deficient human fetus from this family. A similar disorganization of cortical layers was identified in lde/lde rats (carrying a homozygous truncating mutation which disrupts the active Wwox C-terminal domain) investigated at perinatal stages. Transcriptomic analyses of Wwox-depleted human neural progenitor cells showed an impaired expression of a number of neuronal migration-related genes encoding for tubulins, kinesins and associated proteins. These findings indicate that loss of Wwox may affect different cytoskeleton components and alter prenatal cortical development, highlighting a regulatory role of the WWOX gene in migrating neurons across different species.

Mice lacking GAD1 show neonatal mortality, but the human phenotype associated with GAD1 disruption is poorly characterized. Neuray et al. describe six patients with biallelic GAD1 mutations, presenting with early-infantile onset epilepsy, neurodevelopmental delay, muscle weakness and non-CNS manifestations., Gamma-aminobutyric acid (GABA) and glutamate are the most abundant amino acid neurotransmitters in the brain. GABA, an inhibitory neurotransmitter, is synthesized by glutamic acid decarboxylase (GAD). Its predominant isoform GAD67, contributes up to ∼90% of base-level GABA in the CNS, and is encoded by the GAD1 gene. Disruption of GAD1 results in an imbalance of inhibitory and excitatory neurotransmitters, and as Gad1−/− mice die neonatally of severe cleft palate, it has not been possible to determine any potential neurological dysfunction. Furthermore, little is known about the consequence of GAD1 disruption in humans. Here we present six affected individuals from six unrelated families, carrying bi-allelic GAD1 variants, presenting with developmental and epileptic encephalopathy, characterized by early-infantile onset epilepsy and hypotonia with additional variable non-CNS manifestations such as skeletal abnormalities, dysmorphic features and cleft palate. Our findings highlight an important role for GAD1 in seizure induction, neuronal and extraneuronal development, and introduce GAD1 as a new gene associated with developmental and epileptic encephalopathy.

Contains fulltext : 237881.pdf (Publisher’s version ) (Open Access) Human 4-hydroxyphenylpyruvate dioxygenase-like (HPDL) is a putative iron-containing non-heme oxygenase of unknown specificity and biological significance. We report 25 families containing 34 individuals with neurological disease associated with biallelic HPDL variants. Phenotypes ranged from juvenile-onset pure hereditary spastic paraplegia to infantile-onset spasticity and global developmental delays, sometimes complicated by episodes of neurological and respiratory decompensation. Variants included bona fide pathogenic truncating changes, although most were missense substitutions. Functionality of variants could not be determined directly as the enzymatic specificity of HPDL is unknown; however, when HPDL missense substitutions were introduced into 4-hydroxyphenylpyruvate dioxygenase (HPPD, an HPDL orthologue), they impaired the ability of HPPD to convert 4-hydroxyphenylpyruvate into homogentisate. Moreover, three additional sets of experiments provided evidence for a role of HPDL in the nervous system and further supported its link to neurological disease: (i) HPDL was expressed in the nervous system and expression increased during neural differentiation; (ii) knockdown of zebrafish hpdl led to abnormal motor behaviour, replicating aspects of the human disease; and (iii) HPDL localized to mitochondria, consistent with mitochondrial disease that is often associated with neurological manifestations. Our findings suggest that biallelic HPDL variants cause a syndrome varying from juvenile-onset pure hereditary spastic paraplegia to infantile-onset spastic tetraplegia associated with global developmental delays.

The phosphatidylinositol glycan anchor biosynthesis class S protein (PIGS) gene has recently been implicated in a novel congenital disorder of glycosylation resulting in autosomal recessive inherited glycosylphosphatidylinositol‐anchored protein (GPI‐AP) deficiency. Previous studies described seven patients with biallelic variants in the PIGS gene, of whom two presented with fetal akinesia and five with global developmental delay and epileptic developmental encephalopathy. We present the molecular and clinical characteristics of six additional individuals from five families with unreported variants in PIGS. All individuals presented with hypotonia, severe global developmental delay, microcephaly, intractable early infantile epilepsy, and structural brain abnormalities. Additional findings include vision impairment, hearing loss, renal malformation, and hypotonic facial appearances with minor dysmorphic features but without a distinctive facial gestalt. Four individuals died due to neurologic complications. GPI anchoring studies performed on one individual revealed a significant decrease in GPI‐APs. We confirm that biallelic variants in PIGS cause vitamin pyridoxine‐responsive epilepsy due to inherited GPI deficiency and expand the genotype and phenotype of PIGS‐related disorder. Further delineation of the molecular spectrum of PIGS‐related disorders would improve management, help develop treatments, and encourage the expansion of diagnostic genetic testing to include this gene as a potential cause of neurodevelopmental disorders and epilepsy.

Neurodevelopmental disorders (NDDs) are a group of disorders in which the development of the central nervous system (CNS) is disturbed, resulting in different neurological and neuropsychiatric features, such as impaired motor function, learning, language or non-verbal communication. Frequent comorbidities include epilepsy and movement disorders. Advances in DNA sequencing technologies revealed identifiable genetic causes in an increasingly large proportion of NDDs, highlighting the need of experimental approaches to investigate the defective genes and the molecular pathways implicated in abnormal brain development. However, targeted approaches to investigate specific molecular defects and their implications in human brain dysfunction are prevented by limited access to patient-derived brain tissues. In this context, advances of both stem cell technologies and genome editing strategies during the last decade led to the generation of three-dimensional (3D) in vitro-models of cerebral organoids, holding the potential to recapitulate precise stages of human brain development with the aim of personalized diagnostic and therapeutic approaches. Recent progresses allowed to generate 3D-structures of both neuronal and non-neuronal cell types and develop either whole-brain or region-specific cerebral organoids in order to investigate in vitro key brain developmental processes, such as neuronal cell morphogenesis, migration and connectivity. In this review, we summarized emerging methodological approaches in the field of brain organoid technologies and their application to dissect disease mechanisms underlying an array of pediatric brain developmental disorders, with a particular focus on autism spectrum disorders (ASDs) and epileptic encephalopathies.

PURPOSE: To investigate the effect of PLXNA1 variants on the phenotype of patients with autosomal dominant and recessive inheritance patterns and to functionally characterize the zebrafish homologs plxna1a and plxna1b during development. METHODS: We assembled ten patients from seven families with biallelic or de novo PLXNA1 variants. We describe genotype-phenotype correlations, investigated the variants by structural modeling, and used Morpholino knockdown experiments in zebrafish to characterize the embryonic role of plxna1a and plxna1b. RESULTS: Shared phenotypic features among patients include global developmental delay (9/10), brain anomalies (6/10), and eye anomalies (7/10). Notably, seizures were predominantly reported in patients with monoallelic variants. Structural modeling of missense variants in PLXNA1 suggests distortion in the native protein. Our zebrafish studies enforce an embryonic role of plxna1a and plxna1b in the development of the central nervous system and the eye. CONCLUSION: We propose that different biallelic and monoallelic variants in PLXNA1 result in a novel neurodevelopmental syndrome mainly comprising developmental delay, brain, and eye anomalies. We hypothesize that biallelic variants in the extracellular Plexin-A1 domains lead to impaired dimerization or lack of receptor molecules, whereas monoallelic variants in the intracellular Plexin-A1 domains might impair downstream signaling through a dominant-negative effect.

NTNG2 encodes netrin-G2, a membrane-anchored protein implicated in the molecular organization of neuronal circuitry and synaptic organization and diversification in vertebrates. In this study, through a combination of exome sequencing and autozygosity mapping, we have identified 16 individuals (from seven unrelated families) with ultra-rare homozygous missense variants in NTNG2; these individuals present with shared features of a neurodevelopmental disorder consisting of global developmental delay, severe to profound intellectual disability, muscle weakness and abnormal tone, autistic features, behavioral abnormalities, and variable dysmorphisms. The variants disrupt highly conserved residues across the protein. Functional experiments, including in silico analysis of the protein structure, in vitro assessment of cell surface expression, and in vitro knockdown, revealed potential mechanisms of pathogenicity of the variants, including loss of protein function and decreased neurite outgrowth. Our data indicate that appropriate expression of NTNG2 plays an important role in neurotypical development.

Background Striatal cyclic adenosine monophosphate activity modulates movement and is determined from the balance between its synthesis by adenylate cyclase 5 (ADCY5) and its degradation by phosphodiesterase 10A (PDE10A). Objective We assessed the integrity of striatocortical pathways, in vivo, in 2 genetic hyperkinetic disorders caused by ADCY5 and PDE10A mutations. Methods We studied 6 subjects with PDE10A and ADCY5 mutations using [11 C]IMA107 PET, [123 I]FP-CIT Single-photon emission computed tomography (SPECT) and multimodal MRI to investigate PDE10A and dopamine transporter availability, neuromelanin-containing neurons, and microstructural white and gray matter changes, respectively. Results We found that PDE10A and ADCY5 mutations were associated with decreased PDE10A expression in the striatum and globus pallidus, decreased dopamine transporter expression in the striatum, loss of substantia nigra neuromelanin-containing neurons, and microstructural white and gray matter changes within the substantia nigra, striatum, thalamus, and frontoparietal cortices. Conclusions Our findings indicate an association between PDE10A and ADCY5 mutations and pre/postsynaptic molecular changes, substantia nigra damage, and white and gray matter changes within the striatocortical pathways. © 2018 International Parkinson and Movement Disorder Society.

The rapid development in the last 10-15 years of microarray technologies, such as oligonucleotide array Comparative Genomic Hybridization (CGH) and Single Nucleotide Polymorphisms (SNP) genotyping array, has improved the identification of fine chromosomal structural variants, ranging in length from kilobases (kb) to megabases (Mb), as an important cause of genetic differences among healthy individuals and also as disease-susceptibility and/or disease-causing factors. Structural genomic variations due to unbalanced chromosomal rearrangements are known as Copy-Number Variants (CNVs) and these include variably sized deletions, duplications, triplications and translocations. CNVs can significantly contribute to human diseases and rearrangements in several dosage-sensitive genes have been identified as an important causative mechanism in the molecular aetiology of Charcot-Marie-Tooth (CMT) disease and of several CMT-related disorders, a group of inherited neuropathies with a broad range of clinical phenotypes, inheritance patterns and causative genes. Duplications or deletions of the dosage-sensitive gene PMP22 mapped to chromosome 17p12 represent the most frequent causes of CMT type 1A and Hereditary Neuropathy with liability to Pressure Palsies (HNPP), respectively. Additionally, CNVs have been identified in patients with other CMT types (e.g., CMT1X, CMT1B, CMT4D) and different hereditary poly- (e.g., giant axonal neuropathy) and focal- (e.g., hereditary neuralgic amyotrophy) neuropathies, supporting the notion of hereditary peripheral nerve diseases as possible genomic disorders and making crucial the identification of fine chromosomal rearrangements in the molecular assessment of such patients. Notably, the application of advanced computational tools in the analysis of Next-Generation Sequencing (NGS) data has emerged in recent years as a powerful technique for identifying a genome-wide scale complex structural variants (e.g., as the ones resulted from balanced rearrangements) and also smaller pathogenic (intragenic) CNVs that often remain beyond the detection limit of most conventional genomic microarray analyses; in the context of inherited neuropathies where more than 70 disease-causing genes have been identified to date, NGS and particularly Whole-Genome Sequencing (WGS) hold the potential to reduce the number of genomic assays required per patient to reach a diagnosis, analyzing with a single test all the Single Nucleotide Variants (SNVs) and CNVs in the genes possibly implicated in this heterogeneous group of disorders.

Objective Oxidative stress is involved in several maternal conditions characterized both by an increase in free radicals synthesis and a parallel decrease in the antioxidant activity. Parturition induces considerable oxidative stress and many inflammatory mediators, among which HMGB1, are involved from the beginning of pregnancy to the birth of the infant. We evaluated serum cord blood HMGB1 levels in a population of neonates to investigate correlation with mode of delivery, as well as the influence of labour. Setting and patients The study subjects were 325 neonates delivered at University Hospital “G. Martino” of Messina over an 18-month period. Following cord separation, venous blood sampling was performed on umbelical cords. Results In the cord venous blood, we found HMGB1 values significantly more elevated in spontaneous vaginal group when compared to elective or emergency caesarean section group. Regarding labour, umbilical cord venous blood HMGB1 levels were significantly higher in the spontaneous and induced labour group, compared to non-labouring women. Conclusion These results could highlight a possible role of HMGB1 during birth time related to mode of delivery and labour.

Biallelic mutations in the SLC1A4 gene have been identified as a very rare cause of neurodevelopmental disorders. l-serine transport deficiency has been regarded as the causal molecular mechanism underlying the neurological phenotype of SLC1A4 mutation patients. To date this genetic condition has been reported almost exclusively in a limited number of Ashkenazi-Jewish individuals and as a result the SLC1A4 gene is not routinely included in the majority of the genetic diagnostic panels for neurological diseases. We hereby report a 7-year-old boy from a Southern Italian family, presenting with epileptic encephalopathy, congenital microcephaly, global developmental delay, severe hypotonia, spasticity predominant at the lower limbs, and thin corpus callosum. Whole exome sequencing identified a novel segregating SLC1A4 gene homozygous mutation (c.1141G > A: p.Gly381Arg) as the likely cause of the disease in our family. In order to deeply characterize the electro-clinical and neurological phenotype in our index patient, long-term systematic video-electroencephalograms (EEG) as well as repeated brain imaging studies (which included tractographic reconstructions) were performed on a regular basis during a 7 years follow-up time. In conclusion, we suggest to carefully considering SLC1A4 biallelic mutations in individuals presenting an early onset severe neurodevelopmental disorder with variable spasticity and seizures, regardless the patients' ethnic background.

Familial Mediterranean fever (FMF) is the most common autosomal recessive autoinflammatory disease. To date, following the isolation of more than 280 MEFV sequence variants, the genotype-phenotype correlation in FMF patients has been intensively investigated; however, an univocal and clear consensus has not been yet reached. Thus, the aim of this systematic review was to analyze the available literature findings in order to provide to scientific community an indirect estimation of the impact of genetic factors on the phenotypic variability of FMF. This systematic review has been conducted according to the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) guidelines. The p.M694V mutation was reported to have a relatively severe clinical course, similarly, patients homozygous for M694I and M680I, or carrying a combination of both at codons 694 and 680, have a severe disease. Also, patients homozygous for M694V and V726A variants experienced more severe clinical picture. Conversely, heterozygous p.V726A and p.E148Q genotypes have been correlated with a milder disease course. At present, doubts remain on the potential pathogenic role of E148Q variant. The heterogenity in clinical FMF manifestations reflects the changes occuring in repertoire of mutations. We believe that clinical criteria and gene tests, enhancing each other, could better support the diagnosis of FMF.

BackgroundDespite decades that have passed since its discovery, accurate biomarkers of respiratory syncytial virus (RSV) disease activity and effective therapeutic strategies are still lacking. The high-mobility group box type 1 (HMGB1) protein has been proposed as a possible link between RSV and immune system, but only limited information is currently available to support this hypothesis.MethodsExpression of HMGB1 gene and protein was analyzed by quantitative PCR, enzyme-linked immunosorbent assay (ELISA), western blot, immunocytochemistry, and confocal microscopy in immortalized and primary human bronchial epithelial cells, as well as in rat pup lungs. The role of HMGB1 in RSV infection was explored using glycyrrhizin, a selective HMGB1 inhibitor.ResultsRSV infection strongly induced HMGB1 expression both in vitro and in vivo. Glycyrrhizin dose-dependently inhibited HMGB1 upregulation in both RSV-infected immortalized and primary human bronchial epithelial cells, and this effect was associated with significant reduction of viral replication.ConclusionOur data suggest that HMGB1 expression increases during RSV replication. This seems to have a critical pathogenic role as its selective inhibition virtually modified the infection. These observations provide further insight into the pathophysiology of RSV infection and uncover a potential biomarker and therapeutic target for the most common respiratory infection of infancy.

Multiple sclerosis (MS) is increasingly recognized in the paediatric age. In a smaller, but well-established, proportion of paediatric MS patients [20% of total paediatric MS cases: 0.2% to 0.7% of the total MS patients] the onset of disease is before 10 years of age [pre-pubescent (childhood) MS]; in the majority [80%] of paediatric MS patients, however [1.7% to 5.6% of the total MS population], the onset of disease is between 10 and 18 years [post-pubertal (juvenile) MS]. Notably, while pre-pubertal MS occurs almost equally in both genders (female/male ratio = 0.9:1; reverting to 0.4–0.6/1 in pre-school MS children) the female/male ratio rises to 2.2/3:1 in the post-pubertal age. Interestingly, precocious puberty has been associated to: (a) a higher risk of developing MS; and (b) a more severe disease course. In addition to that, males are more susceptible to MS (and manifest more neurodegeneration) than females the latter being however more inflammatory than males; pregnancy however reduces MS relapses. All the above findings led to the suggestion of an underlying female sex hormonal involvement in the pathophysiology of MS vs. a protective role of male sex hormones. Epigenetic perspectives indicate that the interplay between genetic background, environmental triggers and neuroendocrine changes, typically occurring around the time of adolescence, could all play a combined role in initiating and/or promoting MS with onset in the paediatric age including many of the most frequent disease-associated risk factors (e.g., overweight/obesity, low vitamin D levels, reduced sunlight exposure, Epstein-Barr virus infection). According to this proposed complex multifactorial model, susceptibility to MS may be thus acquired during pre-pubertal age and children have probably to wait until the adolescence to manifest their first clinical signs/symptoms.

Objectives: The aim of the study was to investigate whether the rs35761398 variants of the cannabinoid receptor 2 (CB2) gene may influence the acquisition of HIV infection and the clinical presentation of HIV/hepatitis C virus (HCV) coinfection. Methods: We compared 166 HIV/HCV-coinfected patients with 186 HCV-monoinfected patients, all with biopsy-proven chronic hepatitis (using the Ishak scoring system), naïve for anti-HCV treatment and tested for the CB2 rs35761398 polymorphism (using the TaqMan assay). Results: The HIV/HCV-coinfected patients were more frequently male (P

Objectives We evaluated the association between pre-ART HIV DNA and HIV-infected participant characteristics at baseline as well as with their response to first-line ART. Methods Four hundred and thirty-three patients from the ICONA cohort, starting first-line ART after the year 2000, were analysed. Pre-ART HIV DNA was quantified with the modified COBAS TaqMan HIV-1 Test and normalized by CD4+ T cells. Linear correlation between pre-ART HIV DNA and other continuous markers (HIV RNA, CD4 count, markers of inflammation and coagulation) at baseline was evaluated by means of Pearson correlation coefficient and a linear regression model. Survival analyses and Cox regression models were used to study the association between pre-ART HIV DNA and time to VIRO-immunoclinical events. Results Pre-ART HIV DNA [median (IQR): 10 € 702 (3397-36 € 632) copies/10 6 CD4+ T cells] was correlated with pre-ART HIV RNA [R 2 = +0.44, (P < 0.0001)], CD4+ T cells [R 2 = '0.58, (P < 0.0001)] and CD4/CD8 ratio [R 2 = '0.48, (P < 0.0001)], while weaker correlations were observed with CD8+ T cells (R 2 = '0.20, P = 0.01), IL-6 (R 2 = +0.16, P = 0.002) and soluble CD14 (R 2 = +0.09, P = 0.05). Patients with higher pre-ART HIV DNA showed lower rate and delayed VIROlogical response (defined as HIV RNA ≤50 copies/mL), compared with those having lower HIV DNA (67.2% for >10 € 000, 81.1% for 1000-10 € 000 and 86.4% for 10-1000 copies/10 6 CD4+ T cells; P = 0.0004). Higher pre-ART HIV DNA was also correlated with increased risk of VIROlogical rebound (defined as HIV RNA >50 copies/mL) by 24 months (17.2% for >10 € 000, 7.4% for 1000-10 € 000 and 4.3% for 10-1000 copies/10 6 CD4+ T cells; P = 0.0048). Adjusted HRs of all VIROlogical rebound definitions confirmed these findings (P ≤ 0.02). Conclusions Pre-ART HIV DNA, along with HIV RNA and CD4+ T cell count, should be considered as a new staging marker to better identify people at lower (or higher) risk of viral rebound following achievement of VIROlogical suppression (≤50 copies/mL).

Objectives Our primary aim was to study diabetes mellitus (DM) arising during combination ART (cART) and to attempt to identify associations between these cases and triglycerides (TRG) and the TRG to HDL-cholesterol (TRG/HDL) ratio. Our secondary aim was to analyse the association between DM development and hepatic fibrosis. Methods This was a retrospective cohort study. Patients from the Icona Foundation study initiating first-line cART between 1997 and 2013 were selected and observed until new-onset DM or most recent clinical follow-up. The predictive value of TRG and TRG/HDL ratio levels on DM was evaluated using multivariable Poisson regression models. Results Three-thousand, five-hundred and forty-six patients (males, 73.7%; median age, 38 years; median BMI, 23.1 kg/m2; and hepatitis C virus antibody positive, 22.1%) were included. Of these, 80 developed DM over 13 911 person-years of follow-up (PYFU), corresponding to 5.7 cases per 1000 PYFU (95% CI = 4.6–7.1). At multivariable analysis, latest TRG/HDL ratio, when high, was associated with significant increases in DM risk [relative risk (RR) = 1.63; 95% CI = 1.32–2.01 per 10 points higher], while current TRG, in contrast, was associated with new-onset DM only at crude analysis. Advanced liver fibrosis (defined as fibrosis-4 index >3.25) was also shown to be an independent risk factor for DM (RR = 2.91; 95% CI = 1.10–7.72). Conclusions High TRG/HDL ratio predicted risk of new-onset DM, independently of other traditional risk factors. Furthermore, our findings suggest that advanced hepatic fibrosis, estimated using the fibrosis-4 score, could provide an additional predictor for DM.

See Hansen and Møller (doi:10.1093/brain/awz318) for a scientific commentary on this article. Using polygenic risk scores from a genome-wide association study in generalized and focal epilepsy, Leu et al. reveal a significantly higher genetic burden for epilepsy in multiple cohorts of people with epilepsy compared to population controls. Quantification of common variant burden may be valuable for epilepsy prognosis and treatment., Rare genetic variants can cause epilepsy, and genetic testing has been widely adopted for severe, paediatric-onset epilepsies. The phenotypic consequences of common genetic risk burden for epilepsies and their potential future clinical applications have not yet been determined. Using polygenic risk scores (PRS) from a European-ancestry genome-wide association study in generalized and focal epilepsy, we quantified common genetic burden in patients with generalized epilepsy (GE-PRS) or focal epilepsy (FE-PRS) from two independent non-Finnish European cohorts (Epi25 Consortium, n = 5705; Cleveland Clinic Epilepsy Center, n = 620; both compared to 20 435 controls). One Finnish-ancestry population isolate (Finnish-ancestry Epi25, n = 449; compared to 1559 controls), two European-ancestry biobanks (UK Biobank, n = 383 656; Vanderbilt biorepository, n = 49 494), and one Japanese-ancestry biobank (BioBank Japan, n = 168 680) were used for additional replications. Across 8386 patients with epilepsy and 622 212 population controls, we found and replicated significantly higher GE-PRS in patients with generalized epilepsy of European-ancestry compared to patients with focal epilepsy (Epi25: P = 1.64×10−15; Cleveland: P = 2.85×10−4; Finnish-ancestry Epi25: P = 1.80×10−4) or population controls (Epi25: P = 2.35×10−70; Cleveland: P = 1.43×10−7; Finnish-ancestry Epi25: P = 3.11×10−4; UK Biobank and Vanderbilt biorepository meta-analysis: P = 7.99×10−4). FE-PRS were significantly higher in patients with focal epilepsy compared to controls in the non-Finnish, non-biobank cohorts (Epi25: P = 5.74×10−19; Cleveland: P = 1.69×10−6). European ancestry-derived PRS did not predict generalized epilepsy or focal epilepsy in Japanese-ancestry individuals. Finally, we observed a significant 4.6-fold and a 4.5-fold enrichment of patients with generalized epilepsy compared to controls in the top 0.5% highest GE-PRS of the two non-Finnish European cohorts (Epi25: P = 2.60×10−15; Cleveland: P = 1.39×10−2). We conclude that common variant risk associated with epilepsy is significantly enriched in multiple cohorts of patients with epilepsy compared to controls—in particular for generalized epilepsy. As sample sizes and PRS accuracy continue to increase with further common variant discovery, PRS could complement established clinical biomarkers and augment genetic testing for patient classification, comorbidity research, and potentially targeted treatment.

Sequencing-based studies have identified novel risk genes for rare, severe epilepsies and revealed a role of rare deleterious variation in common epilepsies. To identify the shared and distinct ultra-rare genetic risk factors for rare and common epilepsies, we performed a whole-exome sequencing (WES) analysis of 9,170 epilepsy-affected individuals and 8,364 controls of European ancestry. We focused on three phenotypic groups; the rare but severe developmental and epileptic encephalopathies (DEE), and the commoner phenotypes of genetic generalized epilepsy (GGE) and non-acquired focal epilepsy (NAFE). We observed that compared to controls, individuals with any type of epilepsy carried an excess of ultra-rare, deleterious variants in constrained genes and in genes previously associated with epilepsy, with the strongest enrichment seen in DEE and the least in NAFE. Moreover, we found that inhibitory GABAA receptor genes were enriched for missense variants across all three classes of epilepsy, while no enrichment was seen in excitatory receptor genes. The larger gene groups for the GABAergic pathway or cation channels also showed a significant mutational burden in DEE and GGE. Although no single gene surpassed exome-wide significance among individuals with GGE or NAFE, highly constrained genes and genes encoding ion channels were among the top associations, including CACNA1G, EEF1A2, and GABRG2 for GGE and LGI1, TRIM3, and GABRG2 for NAFE. Our study confirms a convergence in the genetics of common and rare epilepsies associated with ultra-rare coding variation and highlights a ubiquitous role for GABAergic inhibition in epilepsy etiology in the largest epilepsy WES study to date.

Background Intellectual disability (ID) is part of the Down syndrome (DS) phenotypic spectrum, but the exact molecular pathophysiology of ID in individuals with DS is not yet fully understood, with many research hypotheses still unproven. Basing on previous studies (which suggested a possible role of altered inflammatory response in DS-related ID), we assessed the serum levels of a number of inflammatory biomarkers [serum amyloid A (SAA), C-reactive protein (C-RP), high mobility group box-1 (HMGB1)] in a cohort of individuals with DS and healthy controls. Methods In total, 24 children diagnosed with DS and 12 healthy controls were enrolled, and all underwent detailed cognitive assessment. Also, serum SAA, C-RP and HMGB1 levels were measured in all recruited subjects and correlated to the severity of ID in the DS group. Results Serum SAA, C-RP and HMGB1 values were found to be significantly higher in the DS group compared with the healthy subjects (P = 0.001). In addition, serum HMGB1 levels positively correlated with C-RP and SAA in the DS group but not in the healthy controls. Only serum C-RP levels resulted inversely correlated (P 0.05). Conclusions The levels of the determined markers were higher in DS individuals compared with (cognitively) healthy subjects, and CRP showed a negative correlation with IQ in children with DS.

We report 2 families with undiagnosed recessive presynaptic congenital myasthenic syndrome (CMS). Whole exome or genome sequencing identified segregating homozygous variants in VAMP1: c.51_64delAGGTGGGGGTCCCC in a Kuwaiti family and c.146G>C in an Israeli family. VAMP1 is crucial for vesicle fusion at presynaptic neuromuscular junction (NMJ). Electrodiagnostic examination showed severely low compound muscle action potentials and presynaptic impairment. We assessed the effect of the nonsense mutation on mRNA levels and evaluated the NMJ transmission in VAMP1lew/lew mice, observing neurophysiological features of presynaptic impairment, similar to the patients. Taken together, our findings highlight VAMP1 homozygous mutations as a cause of presynaptic CMS. Ann Neurol 2017;81:597–603

Cytogenic testing is routinely applied in most neurological centres for severe paediatric epilepsies. However, which characteristics of copy number variants (CNVs) confer most epilepsy risk and which epilepsy subtypes carry the most CNV burden, have not been explored on a genome-wide scale. Here, we present the largest CNV investigation in epilepsy to date with 10 712 European epilepsy cases and 6746 ancestry-matched controls. Patients with genetic generalized epilepsy, lesional focal epilepsy, non-acquired focal epilepsy, and developmental and epileptic encephalopathy were included. All samples were processed with the same technology and analysis pipeline. All investigated epilepsy types, including lesional focal epilepsy patients, showed an increase in CNV burden in at least one tested category compared to controls. However, we observed striking differences in CNV burden across epilepsy types and investigated CNV categories. Genetic generalized epilepsy patients have the highest CNV burden in all categories tested, followed by developmental and epileptic encephalopathy patients. Both epilepsy types also show association for deletions covering genes intolerant for truncating variants. Genome-wide CNV breakpoint association showed not only significant loci for genetic generalized and developmental and epileptic encephalopathy patients but also for lesional focal epilepsy patients. With a 34-fold risk for developing genetic generalized epilepsy, we show for the first time that the established epilepsy-associated 15q13.3 deletion represents the strongest risk CNV for genetic generalized epilepsy across the whole genome. Using the human interactome, we examined the largest connected component of the genes overlapped by CNVs in the four epilepsy types. We observed that genetic generalized epilepsy and non-acquired focal epilepsy formed disease modules. In summary, we show that in all common epilepsy types, 1.5–3% of patients carry epilepsy-associated CNVs. The characteristics of risk CNVs vary tremendously across and within epilepsy types. Thus, we advocate genome-wide genomic testing to identify all disease-associated types of CNVs.

The myosin-directed chaperone UNC-45B is essential for sarcomeric organization and muscle function from Caenorhabditis elegans to humans. The pathological impact of UNC-45B in muscle disease remained elusive. We report ten individuals with bi-allelic variants in UNC45B who exhibit childhood-onset progressive muscle weakness. We identified a common UNC45B variant that acts as a complex hypomorph splice variant. Purified UNC-45B mutants showed changes in folding and solubility. In situ localization studies further demonstrated reduced expression of mutant UNC-45B in muscle combined with abnormal localization away from the A-band towards the Z-disk of the sarcomere. The physiological relevance of these observations was investigated in C. elegans by transgenic expression of conserved UNC-45 missense variants, which showed impaired myosin binding for one and defective muscle function for three. Together, our results demonstrate that UNC-45B impairment manifests as a chaperonopathy with progressive muscle pathology, which discovers the previously unknown conserved role of UNC-45B in myofibrillar organization.

ObjectiveTo estimate the prevalence of Joubert syndrome (JS) in Italy applying standards of descriptive epidemiology and to provide a molecular characterization of the described patient cohort.MethodsWe enrolled all patients with a neuroradiologically confirmed diagnosis of JS who resided in Italy in 2018 and calculated age and sex prevalence, assuming a Poisson distribution. We also investigated the correlation between proband chronological age and age at diagnosis and performed next-generation sequencing (NGS) analysis on probands' DNA when available.ResultsWe identified 284 patients with JS: the overall, female- and male-specific population-based prevalence rates were 0.47 (95% confidence interval [CI] 0.41–0.53), 0.41 (95% CI 0.32–0.49), and 0.53 (95% CI 0.45–0.61) per 100,000 population, respectively. When we considered only patients in the age range from 0 to 19 years, the corresponding population-based prevalence rates rose to 1.7 (95% CI 1.49–1.97), 1.62 (95% CI 1.31–1.99), and 1.80 (95% CI 1.49–2.18) per 100,000 population. NGS analysis allowed identifying the genetic cause in 131 of 219 screened probands. Age at diagnosis was available for 223 probands, with a mean of 6.67 ± 8.10 years, and showed a statistically significant linear relationship with chronological age (r2 = 0.79; p < 0.001).ConclusionsWe estimated for the first time the age and sex prevalence of JS in Italy and investigated the patients’ genetic profile. The obtained population-based prevalence rate was ≈10 times higher than that available in literature for children population.

Heterozygous mutations in REEP1 (MIM #609139) encoding the receptor expression-enhancing protein 1 (REEP1) are a well-recognized and relatively frequent cause of autosomal dominant hereditary spastic paraplegia (HSP), SPG31.1 REEP1 localizes in the mitochondria and endoplasmic reticulum (ER) and facilitates ER-mitochondria interactions.2 In addition to the HSP phenotype, REEP1 has been associated with an autosomal dominant spinal type of Charcot-Marie-Tooth disease in 2 families.3 More recently, a patient with homozygous REEP1 mutation with a much more severe phenotype akin to spinal muscular atrophy with respiratory distress type 1 (SMARD1) was reported.4 In this report, we present a patient with a homozygous mutation in REEP1 manifesting a severe congenital distal spinal muscular atrophy (SMA) with diaphragmatic paralysis, expanding the phenotype from mild autosomal dominant HSP through to severe recessive distal SMA pattern.

Charcot-Marie-Tooth type 4 (CMT4) is an autosomal recessive severe form of neuropathy with genetic heterogeneity. CMT4B1 is caused by mutations in the myotubularin-related 2 (MTMR2) gene and as a member of the myotubularin family, the MTMR2 protein is crucial for the modulation of membrane trafficking. To enable future clinical trials, we performed a detailed review of the published cases with MTMR2 mutations and describe four novel cases identified through whole-exome sequencing (WES). The four unrelated families harbor novel homozygous mutations in MTMR2 (NM_016156, Family 1: c.1490dupC; p.Phe498IlefsTer2; Family 2: c.1479+1G>A; Family 3: c.1090C>T; p.Arg364Ter; Family 4: c.883C>T; p.Arg295Ter) and present with CMT4B1-related severe early-onset motor and sensory neuropathy, generalized muscle atrophy, facial and bulbar weakness, and pes cavus deformity. The clinical description of the new mutations reported here overlap with previously reported CMT4B1 phenotypes caused by mutations in the phosphatase domain of MTMR2, suggesting that nonsense MTMR2 mutations, which are predicted to result in loss or disruption of the phosphatase domain, are associated with a severe phenotype and loss of independent ambulation by the early twenties. Whereas the few reported missense mutations and also those truncating mutations occurring at the C-terminus after the phosphatase domain cause a rather mild phenotype and patients were still ambulatory above the age 30 years. Charcot-Marie-Tooth neuropathy and Centronuclear Myopathy causing mutations have been shown to occur in proteins involved in membrane remodeling and trafficking pathway mediated by phosphoinositides. Earlier studies have showing the rescue of MTM1 myopathy by MTMR2 overexpression, emphasize the importance of maintaining the phosphoinositides equilibrium and highlight a potential compensatory mechanism amongst members of this pathway. This proved that the regulation of expression of these proteins involved in the membrane remodeling pathway may compensate each other's loss- or gain-of-function mutations by restoring the phosphoinositides equilibrium. This provides a potential therapeutic strategy for neuromuscular diseases resulting from mutations in the membrane remodeling pathway.

Objective: This is the first study to analyze the impact of the rs35761398 variant of the CNR2 gene leading to the substitution of GLN (Q) of codon 63 of the cannabinoid receptor 2 (CB2) with ARG (R) on the clinical presentation of chronic hepatitis in HIV/HCV coinfected patients. Methods: Enrolled in this study were 166 consecutive HIV/HCV coinfected patients, naïve for HCV treatment. A pathologist unaware of the patients’ condition graded liver fibrosis, necroinflammation (Ishak) and steatosis. All patients were screened for the CB2 rs35761398 polymorphism. Results: Of the 166 HIV/HCV coinfected patients, 72.9% were males, 42.5% were infected with HCV-genotype-3 and 60.2% had been intravenous drug users. The median age was 40.6 years and the immunological condition good (median CD4+cells/mm3= 507, IQR: 398.0–669.5). Thirty-five (21.1%) patients were naive for ART and 131(78.9%) were on ART. The CB2-RR variant was detected in 45.8% of patients, QR in 38.6% and QQ in 15.7%. Patients with CB2-RR showed a necroinflammation score (HAI) ≥9 more frequently than those with CB2-QQ or CB2-QR (32.9% vs. 11.5% and 14.1%, respectively, p≤0.001). In the multivariate analysis, the CB2-RR variant (p = 0.03) and liver fibrosis were both identified as independent predictors of the entity of liver necroinflammation (p = 0.0001). Conclusion: This study shows interesting interplay between the CB2-RR variant and liver necroinflammation in chronic hepatitis patients with HIV/HCV coinfection, an observation of clinical value that coincides with the interest in the use of the CB2 agonists and antagonists in clinical practice emerging from the literature.

We described a 5-year-old male with hypodontia, hypohidrosis, and facial dysmorphisms characterized by a depressed nasal bridge, maxillary hypoplasia, and protuberant lips. Chromosomal analysis revealed a normal 46,XY male karyotype. Due to the presence of clinical features of hypohidrotic ectodermal dysplasia (HED), the EDA gene, located at Xq12q13.1, of the patient and his family was sequenced. Analysis of the proband's sequence revealed a missense mutation (T to A transversion) in hemizygosity state at nucleotide position 158 in exon 1 of the EDA gene, which changes codon 53 from leucine to histidine, while heterozygosity at this position was detected in the slightly affected mother; moreover, this mutation was not found in the publically available Human Gene Mutation Database. To date, our findings indicate that a novel mutation in EDA is associated with X-linked HED, adding it to the repertoire of EDA mutations.

Objective The hemojuvelin-bone morphogenetic protein axis is the principal iron-dependent mechanism of hepcidin regulation. The determination of sHJV levels could allow for a better understanding of the pathophysiological mechanisms of hepcidin regulation in thalassaemia. Method We have assessed soluble hemojuvelin (sHJV) in 45 transfused and 15 untransfused thalassaemic patients in comparison to 15 healthy subjects, evaluating its relationships with some parameters of iron overload, anaemia and erythropoiesis. Results Untransfused thalassaemic patients had more severe anaemia and erythropoietic activity, while in transfused patients, the transfused RBCs reduced % reticulocytes and sTfR, increased serum indices of iron overload and iron stores in the liver (low RMI T2* values). sHJV levels were higher in patients than in controls and in untransfused in comparison to transfused patients. In the transfused group, we also found that sHJV values are significantly related to serum ferritin, cardiac MRI T2* and growth differentiation factor 15 and are sensitive to hepatitis C virus infection. Conclusion These results suggest that sHJV synthesis seems to be affected by an erythropoietic/hypoxic signal in untransfused patients that have severe anaemia, while in regularly transfused subjects, it is influenced by iron stores. This article is protected by copyright. All rights reserved.

International audience; We identified individuals with variations in ACTL6B, a component of the chromatin remodeling machinery including the BAF complex. Ten individuals harbored bi-allelic mutations and presented with global developmental delay, epileptic encephalopathy, and spasticity, and ten individuals with de novo heterozygous mutations displayed intellectual disability, ambulation deficits, severe language impairment, hypotonia, Rett-like stereotypies, and minor facial dysmorphisms (wide mouth, diastema, bulbous nose). Nine of these ten unrelated individuals had the identical de novo c.1027G>A (p.Gly343Arg) mutation. Human-derived neurons were generated that recaptured ACTL6B expression patterns in development from progenitor cell to post-mitotic neuron, validating the use of this model. Engineered knock-out of ACTL6B in wild-type human neurons resulted in profound deficits in dendrite development, a result recapitulated in two individuals with different bi-allelic mutations, and reversed on clonal genetic repair or exogenous expression of ACTL6B. Whole-transcriptome analyses and whole-genomic profiling of the BAF complex in wild-type and bi-allelic mutant ACTL6B neural progenitor cells and neurons revealed increased genomic binding of the BAF complex in ACTL6B mutants, with corresponding transcriptional changes in several genes including TPPP and FSCN1, suggesting that altered regulation of some cytoskeletal genes contribute to altered dendrite development. Assessment of bi-alleic and heterozygous ACTL6B mutations on an ACTL6B knock-out human background demonstrated that bi-allelic mutations mimic engineered deletion deficits while heterozygous mutations do not, suggesting that the former are loss of function and the latter are gain of function. These results reveal a role for ACTL6B in neurodevelopment and implicate another component of chromatin remodeling machinery in brain disease.

Mutations in genes involved in chromatin remodelling have been implicated in broad phenotypes of congenital abnormalities and neurodevelopment. However, limited genotype-phenotype correlations are available for some of the rarest genetic disorders that affect chromatin regulation. We hereby describe a 12-year-old girl presented at birth with severe hypotonia, developmental delay, a mid-line capillary malformation and distinctive craniofacial features. During the natural history of her disease, the girl developed severe spasticity and drug-resistant seizures, leading to a diagnosis of Bohring-Opitz syndrome (BOS). We performed whole-exome sequencing (WES) and identified a de novo mutation in ASXL1 (c.2033dupG) which results in the introduction of a premature stop codon (p.R678fs*6). ASXL1 encodes a polycomb repressive complex protein implicated in chromatin regulation and de novo mutations are a known cause of BOS. Phenotypes with segmental craniofacial overgrowth associated to midline capillary malformations enlarge the clinical spectrum of BOS at onset and further expand the differential diagnosis in ASXL1 mutation carriers.

The growing interest in the new role of vitamin D, particularly as an immunomodulatory factor, has spurred basic research and the development of clinical trials to better understand the influence of supplementation on various diseases. Vitamin D is an important nutrient factor in human health due to its role in calcium metabolism regulation, cellular growth, differentiation and its fundamental discovered activity in immune functions. It has influenced different diseases, particularly inflammatory and autoimmune diseases, through immune response regulation, modulating innate and adaptive immunity. : The aim of this review was to explore the role of vitamin D in the main respiratory diseases in children such as asthma, chronic rhinosinusitis, cystic fibrosis and recurrent respiratory infections.