Biallelic PI4KA variants cause a novel neurodevelopmental syndrome with hypomyelinating leukodystrophy

Hypomyelinating leukodystrophy; Inborn errors of metabolism; PhosphoinositolLeucodistrofia hipomielinizante; Errores innatos del metabolismo; FosfoinositolLeucodistròfia hipomielinizant; Errors innats del metabolisme; FosfoinositolPhosphoinositides are lipids that play a critical role in processes such as cellular signalling, ion channel activity and membrane trafficking. When mutated, several genes that encode proteins that participate in the metabolism of these lipids give rise to neurological or developmental phenotypes. PI4KA is a phosphoinositide kinase that is highly expressed in the brain and is essential for life. Here we used whole exome or genome sequencing to identify 10 unrelated patients harbouring biallelic variants in PI4KA that caused a spectrum of conditions ranging from severe global neurodevelopmental delay with hypomyelination and developmental brain abnormalities to pure spastic paraplegia. Some patients presented immunological deficits or genito-urinary abnormalities. Functional analyses by western blotting and immunofluorescence showed decreased PI4KA levels in the patients’ fibroblasts. Immunofluorescence and targeted lipidomics indicated that PI4KA activity was diminished in fibroblasts and peripheral blood mononuclear cells. In conclusion, we report a novel severe metabolic disorder caused by PI4KA malfunction, highlighting the importance of phosphoinositide signalling in human brain development and the myelin sheath.We thank the CERCA Program/Generalitat de Catalunya for institutional support. This study was supported by grants from the Hesperia Foundation, the Asociación Española contra las Leucodistrofias (ALE-ELA España), the Autonomous Government of Catalonia (SGR 2017SGR1206 and PERIS program URD-Cat SLT002/16/00174) and the Center for Biomedical Research on Rare Diseases (CIBERER) (ACCI19-759 to A.P.). This study was also funded by Fundació La Marató de TV3 (595/C/2020) as well as Instituto de Salud Carlos III (FIS PI20/00758 to C.C.) (co-funded by European Regional Development Fund. ERDF, a way to build Europe). This study was also funded by the Instituto de Salud Carlos III (Rio Hortega, CM18/00145 to V.V.; PFIS, FI18/00141 to L.P.; and Sara Borrell, CD19/00221 to E.V.), co-funded by European Social Fund. ESF investing in your future; the Ministerio de Ciencia e Innovación y Universidades (Juan de la Cierva, FJCI-2016-28811 to E.V.), and the Center for Biomedical Research on Rare Diseases (CIBERER to M.R.). Sequencing and analysis of Patient 5 were performed by the Broad Institute of MIT and Harvard Center for Mendelian Genomics (Broad CMG) and were funded by the National Human Genome Research Institute, the National Eye Institute, the National Heart, Lung and Blood Institute grants UM1 HG008900 and R01 HG009141 and the Chan Zuckerberg Initiative to the Rare Genomes Project. This work was in part supported by the association ‘Connaître les Syndromes Cérébelleux’ (CSC). This research received funding specifically appointed to the Department of Medical Sciences from the Italian Ministry for Education, University and Research (Ministero dell’istruzione, dell’università e della ricerca-MIUR) under the programme ‘Dipartimenti di Eccellenza 2018-2022’ Project code D15D18000410001. Whole-exome sequencing was performed as part of the Autism Sequencing Consortium and was supported by the NIMH (MH111661). D.R.A. and A.P. are members of the Undiagnosed Disease Network International (UDNI)

Accelerated biological aging in COVID-19 patients

Chronological age is a risk factor for SARS-CoV-2 infection and severe COVID-19. Previous findings indicate that epigenetic age could be altered in viral infection. However, the epigenetic aging in COVID-19 has not been well studied. In this study, DNA methylation of the blood samples from 232 healthy individuals and 413 COVID-19 patients is profiled using EPIC methylation array. Epigenetic ages of each individual are determined by applying epigenetic clocks and telomere length estimator to the methylation profile of the individual. Epigenetic age acceleration is calculated and compared between groups. We observe strong correlations between the epigenetic clocks and individual's chronological age (r > 0.8, p < 0.0001). We also find the increasing acceleration of epigenetic aging and telomere attrition in the sequential blood samples from healthy individuals and infected patients developing non-severe and severe COVID-19. In addition, the longitudinal DNA methylation profiling analysis find that the accumulation of epigenetic aging from COVID-19 syndrome could be partly reversed at late clinic phases in some patients. In conclusion, accelerated epigenetic aging is associated with the risk of SARS-CoV-2 infection and developing severe COVID-19. In addition, the accumulation of epigenetic aging from COVID-19 may contribute to the post-COVID-19 syndrome among survivors. Age is a risk factor for SARS-CoV-2 infection and severe disease. Here the authors perform DNA methylation analyses in whole blood from COVID-19 patients using established epigenetic clocks and telomere length estimators, and describing correlations between epigenetic aging and the risk of SARS-CoV-2 infection and severe disease

Neutralizing Autoantibodies to Type I IFNs in >10% of Patients with Severe COVID-19 Pneumonia Hospitalized in Madrid, Spain

Background: In a recent study, autoantibodies neutralizing type I interferons (IFNs) were present in at least 10% of cases of critical COVID-19 pneumonia. These autoantibodies neutralized most type I IFNs but rarely IFN-beta. Objectives: We aimed to define the prevalence of autoantibodies neutralizing type I IFN in a cohort of patients with severe COVID-19 pneumonia treated with IFN-beta-1b during hospitalization and to analyze their impact on various clinical variables and outcomes. Methods: We analyzed stored serum/plasma samples and clinical data of COVID-19 patients treated subcutaneously with IFN-beta-1b from March to May 2020, at the Infanta Leonor University Hospital in Madrid, Spain. Results: The cohort comprised 47 COVID-19 patients with severe pneumonia, 16 of whom (34%) had a critical progression requiring ICU admission. The median age was 71 years, with 28 men (58.6%). Type I IFN-alpha- and omega-neutralizing autoantibodies were found in 5 of 47 patients with severe pneumonia or critical disease (10.6%), while they were not found in any of the 118 asymptomatic controls (p = 0.0016). The autoantibodies did not neutralize IFN-beta. No demographic, comorbidity, or clinical differences were seen between individuals with or without autoantibodies. We found a significant correlation between the presence of neutralizing autoantibodies and higher C-reactive protein levels (p = 5.10e-03) and lower lymphocyte counts (p = 1.80e-02). No significant association with response to IFN-beta-1b therapy (p = 0.34) was found. Survival analysis suggested that neutralizing autoantibodies may increase the risk of death (4/5, 80% vs 12/42, 28.5%). Conclusion: Autoantibodies neutralizing type I IFN underlie severe/critical COVID-19 stages in at least 10% of cases, correlate with increased C-RP and lower lymphocyte counts, and confer a trend towards increased risk of death. Subcutaneous IFN-beta treatment of hospitalized patients did not seem to improve clinical outcome. Studies of earlier, ambulatory IFN-beta treatment are warranted

A deep intronic splice variant advises reexamination of presumably dominant SPG7 Cases

Objective: to identify causative mutations in a patient affected by ataxia and spastic paraplegia. Methods: whole-exome sequencing (WES) and whole-genome sequencing (WGS) were performed using patient's DNA sample. RT-PCR and cDNA Sanger sequencing were performed on RNA extracted from patient's fibroblasts, as well as western blot. Results: a novel missense variant in SPG7 (c.2195T> C; p.Leu732Pro) was first found by whole-exome sequencing (WES), while the second, also unreported, deep intronic variant (c.286 + 853A>G) was identified by whole-genome sequencing (WGS). RT-PCR confirmed the in silico predictions showing that this variant activated a cryptic splice site, inducing the inclusion of a pseudoexon into the mRNA sequence, which encoded a premature stop codon. Western blot showed decreased SPG7 levels in patient's fibroblasts. Interpretation: identification of a deep intronic variant in SPG7, which could only have been detected by performing WGS, led to a diagnosis in this HSP patient. This case challenges the notion of an autosomal dominant inheritance for SPG7, and illustrates the importance of performing WGS subsequently or alternatively to WES to find additional mutations, especially in patients carrying one variant in a gene causing a predominantly autosomal recessive disease

Faunística i distribució dels odonats d?Osona

Es presenta la faunística i la distribució dels odonats d'Osona, a partir de dades d'adults recollides en 17 itineraris durant els anys 1988-89. S'ha detectat 36 espècies (16 anisòpters i 20 zigòpters) que representen el 55,4 % de les presents a Catalunya. Lestes viridis i Anax imperator són les de distribució més àmplia i Platycnemis latipes i L.viridis les més abundants. Olost, Sora i el Sorreigs són els itineraris amb major nombre d'espècies. Finalment es discuteixen aspectes referents a l'abundància, distribució i ecologia de les espècies osonenques.The odonate fauna of Osona (Barcelona, Spain) and its distribution are presented, on the basis of data from adults obtained in 17 itineraries during the period 1988-89. Thirty-six species were detected (16 anisopterans and 20 zygopterans), representing 55,4 % of those recorded from Catalonia. Lestes viridis and Anax imperator have the widest distribution and Platycnemis latipes and L. viridis are the most abundant. Olost, Sora and El Sorreigs are the itineraries with the largest numbers of species. Finally, some aspects of the abundance, distribution and ecology of the species present in Osona are discussed.Se presenta la faunística y la distribución de los odonatos de Osona (Barcelona), a partir de datos de adultos recopilados en 17 itinerarios durante los años 1988-89. Se han detectado 36 especies (16 anisópteros y 20 zigópteros) que representan el 55,4 % de las presentes en Cataluña. Lestes viridis y Anax imperator son las de distribución más amplia y Platycnemis latipes y L.viridis las más abundantes. Olost, Sora y el Sorreigs son los itinerarios con mayor número de especies. Finalmente se discuten aspectos referentes a la abundancia, distribución y ecología de les especies de Osona

Activating cannabinoid receptor 2 preserves axonal health through GSK-3β/NRF2 axis in adrenoleukodystrophy

Aberrant endocannabinoid signaling accompanies several neurodegenerative disorders, including multiple sclerosis. Here, we report altered endocannabinoid signaling in X-linked adrenoleukodystrophy (X-ALD), a rare neurometabolic demyelinating syndrome caused by malfunction of the peroxisomal ABCD1 transporter, resulting in the accumulation of very long-chain fatty acids (VLCFAs). We found abnormal levels of cannabinoid receptor 2 (CB2r) and related endocannabinoid enzymes in the brain and peripheral blood mononuclear cells (PBMCs) of X-ALD patients and in the spinal cord of a murine model of X-ALD. Preclinical treatment with a selective agonist of CB2r (JWH133) halted axonal degeneration and associated locomotor deficits, along with normalization of microgliosis. Moreover, the drug improved the main metabolic disturbances underlying this model, particularly in redox and lipid homeostatic pathways, including increased lipid droplets in motor neurons, through the modulation of the GSK-3β/NRF2 axis. JWH133 inhibited Reactive Oxygen Species elicited by excess VLCFAs in primary microglial cultures of Abcd1-null mice. Furthermore, we uncovered intertwined redox and CB2r signaling in the murine spinal cords and in patient PBMC samples obtained from a phase II clinical trial with antioxidants (NCT01495260). These findings highlight CB2r signaling as a potential therapeutic target for X-ALD and perhaps other neurodegenerative disorders that present with dysregulated redox and lipid homeostasis.This study was funded by the Institute of Health Carlos III through projects [PI19/01008] to SF and [PI20/00759] to AP (co-funded by the European Regional Development Fund, ERDF, a way to build Europe), Miguel Servet program [CPII16/00016] to SF and [PFIS, FI18/00141] to LPS (co-funded by the European Social Fund, ESF investing in your future). This study was also funded by grants from the Spanish Ministry of Health, Social Services and Equality (EC10-137), the Autonomous Government of Catalonia [2017SGR1206], the Hesperia Foundation, CERTIS Obres i Serveis, and the Crowd funding Campaign Arnau’97 to AP. JP was a predoctoral fellow of IDIBELL. The Center for Biomedical Research on Rare Diseases (CIBERER), an initiative of the Institute of Health Carlos III, funded the position of MR. Locomotor experiments were performed by the SEFALer unit F5 led by AP, which belongs to the CIBERER structure. We thank the CERCA Program/Generalitat de Catalunya for institutional support

RINT1 deficiency disrupts lipid metabolism and underlies a complex hereditary spastic paraplegia

The Rad50 interacting protein 1 (Rint1) is a key player in vesicular trafficking between the ER and Golgi apparatus. Biallelic variants in RINT1 cause infantile-onset episodic acute liver failure (ALF). Here, we describe 3 individuals from 2 unrelated families with novel biallelic RINT1loss-of-function variants who presented with early onset spastic paraplegia, ataxia, optic nerve hypoplasia, and dysmorphic features, broadening the previously described phenotype. Our functional and lipidomic analyses provided evidence that pathogenic RINT1 variants induce defective lipid-droplet biogenesis and profound lipid abnormalities in fibroblasts and plasma that impact both neutral lipid and phospholipid metabolism, including decreased triglycerides and diglycerides, phosphatidylcholine/phosphatidylserine ratios, and inhibited Lands cycle. Further, RINT1 mutations induced intracellular ROS production and reduced ATP synthesis, affecting mitochondria with membrane depolarization, aberrant cristae ultrastructure, and increased fission. Altogether, our results highlighted the pivotal role of RINT1 in lipid metabolism and mitochondria function, with a profound effect in central nervous system development

Sphingolipid desaturase DEGS1 is essential for mitochondria-associated membrane integrity

Sphingolipids function as membrane constituents and signaling molecules, with crucial roles in human diseases, from neurodevelopmental disorders to cancer, best exemplified in the inborn errors of sphingolipid metabolism in lysosomes. The dihydroceramide desaturase Delta 4-dihydroceramide desaturase 1 (DEGS1) acts in the last step of a sector of the sphingolipid pathway, de novo ceramide biosynthesis. Defects in DEGS1 cause the recently described hypomyelinating leukodystrophy-18 (HLD18) (OMIM #618404). Here, we reveal that DEGS1 is a mitochondria-associated endoplasmic reticulum membrane-resident (MAM-resident) enzyme, refining previous reports locating DEGS1 at the endoplasmic reticulum only. Using patient fibroblasts, multiomics, and enzymatic assays, we show that DEGS1 deficiency disrupts the main core functions of the MAM: (a) mitochondrial dynamics, with a hyperfused mitochondrial network associated with decreased activation of dynamin-related protein 1; (b) cholesterol metabolism, with impaired sterol O-acyltransferase activity and decreased cholesteryl esters; (c) phospholipid metabolism, with increased phosphatidic acid and phosphatidylserine and decreased phosphatidylethanolamine; and (d) biogenesis of lipid droplets, with increased size and numbers. Moreover, we detected increased mitochondrial superoxide species production in fibroblasts and mitochondrial respiration impairment in patient muscle biopsy tissues. Our findings shed light on the pathophysiology of HLD18 and broaden our understanding of the role of sphingolipid metabolism in MAM function

Inborn errors of type I IFN immunity in patients with life-threatening COVID-19

Clinical outcome upon infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ranges from silent infection to lethal coronavirus disease 2019 (COVID-19). We have found an enrichment in rare variants predicted to be loss-of-function (LOF) at the 13 human loci known to govern Toll-like receptor 3 (TLR3)- and interferon regulatory factor 7 (IRF7)-dependent type I interferon (IFN) immunity to influenza virus in 659 patients with life-threatening COVID-19 pneumonia relative to 534 subjects with asymptomatic or benign infection. By testing these and other rare variants at these 13 loci, we experimentally defined LOF variants underlying autosomal-recessive or autosomal-dominant deficiencies in 23 patients (3.5%) 17 to 77 years of age. We show that human fibroblasts with mutations affecting this circuit are vulnerable to SARS-CoV-2. Inborn errors of TLR3-and IRF7-dependent type I IFN immunity can underlie life-threatening COVID-19 pneumonia in patients with no prior severe infection

HNRNPH1 ‐related syndromic intellectual disability: Seven additional cases suggestive of a distinct syndromic neurodevelopmental syndrome

Pathogenic variants in HNRNPH1 were first reported in 2018. The reported individual, a 13 year old boy with a c.616C>T (p.R206W) variant in the HNRNPH1 gene, was noted to have overlapping symptoms with those observed in HNRNPH2-related X-linked intellectual disability, Bain type (MRXSB), specifically intellectual disability and dysmorphic features. While HNRNPH1 variants were initially proposed to represent an autosomal cause of MRXSB, we report an additional seven cases which identify phenotypic differences from MRXSB. Patients with HNRNPH1 pathogenic variants diagnosed via WES were identified using clinical networks and GeneMatcher. Features unique to individuals with HNRNPH1 variants include distinctive dysmorphic facial features; an increased incidence of congenital anomalies including cranial and brain abnormalities, genitourinary malformations, and palate abnormalities; increased incidence of ophthalmologic abnormalities; and a decreased incidence of epilepsy and cardiac defects compared to those with MRXSB. This suggests that pathogenic variants in HNRNPH1 result in a related, but distinct syndromic cause of intellectual disability from MRXSB, which we refer to as HNRNPH1-related intellectual disability