Expanding the natural history of CASK-related disorders to the prenatal period

Aim To assess whether microcephaly with pontine and cerebellar hypoplasia (MICPCH) could manifest in the prenatal period in patients with calcium/calmodulin-dependent serine protein kinase (CASK) gene disorders. Method In this international multicentre retrospective study, we contacted a CASK parents' social media group and colleagues with expertise in cerebellar malformations and asked them to supply clinical and imaging information. Centiles and standard deviations (SD) were calculated according to age by nomograms. Results The study consisted of 49 patients (44 females and 5 males). Information regarding prenatal head circumference was available in 19 patients; 11 out of 19 had a fetal head circumference below -2SD (range -4.1SD to -2.02SD, mean gestational age at diagnosis 20 weeks). Progressive prenatal deceleration of head circumference growth rate was observed in 15 out of 19. At birth, 20 out of 42 had a head circumference below -2SD. A total of 6 out of 15 fetuses had a TCD z-score below -2 (range -5.88 to -2.02). Interpretation This study expands the natural history of CASK-related disorders to the prenatal period, showing evidence of progressive deceleration of head circumference growth rate, head circumference below -2SD, or small TCD. Most cases will not be diagnosed according to current recommendations for fetal central nervous system routine assessment. Consecutive measurements and genetic studies are advised in the presence of progressive deceleration of head circumference growth rates or small TCD

Preventing Pseudomonas aeruginosa and Chromobacterium violaceum infections by anti-adhesion-active components of edible seeds

<p>Abstract</p> <p>Background</p> <p><it>Pseudomonas aeruginosa </it>adhesion to animal/human cells for infection establishment involves adhesive proteins, including its galactose- and fucose-binding lectins PA-IL (LecA) and PA-IIL (LecB). The lectin binding to the target-cell receptors may be blocked by compatible glycans that compete with those of the receptors, functioning as anti-adhesion glycodecoys. The anti-adhesion treatment is of the utmost importance for abrogating devastating antibiotic-resistant <it>P. aeruginosa </it>infections in immunodeficient and cystic fibrosis (CF) patients. This strategy functions in nature in protecting embryos and neonates. We have shown that PA-IL, PA-IIL, and also CV-IIL (a PA-IIL homolog produced in the related pathogen <it>Chromobacterium violaceum</it>) are highly useful for revealing natural glycodecoys that surround embryos in diverse avian eggs and are supplied to neonates in milks and royal jelly. In the present study, these lectins were used as probes to search for seed embryo-protecting glycodecoys.</p> <p>Methods</p> <p>The lectin-blocking glycodecoy activities were shown by the hemagglutination-inhibition test. Lectin-binding glycoproteins were detected by Western blotting with peroxidase-labeled lectins.</p> <p>Results</p> <p>The present work reports the finding - by using PA-IL, PA-IIL, and CV-IIL - of rich glycodecoy activities of low (< 10 KDa) and high MW (> 10 kDa) compounds (including glycoproteins) in extracts of cashew, cocoa, coffee, pumpkin, and tomato seeds, resembling those of avian egg whites, mammal milks, and royal jelly.</p> <p>Conclusions</p> <p>Edible seed extracts possess lectin-blocking glycodecoys that might protect their embryos from infections and also might be useful for hampering human and animal infections.</p

Clinical phenotypes of infantile onset CACNA1A-related disorder

BACKGROUND: CACNA1A-related disorders present with persistent progressive and non-progressive cerebellar ataxia and paroxysmal events: epileptic seizures and non-epileptic attacks. These phenotypes overlap and co-exist in the majority of patients. OBJECTIVE: To describe phenotypes in infantile onset CACNA1A-related disorder and to explore intra-familial variations and genotype-phenotype correlations. MATERIAL AND METHODS: This study was a multicenter international collaboration. A retrospective chart review of CACNA1A patients was performed. Clinical, radiological, and genetic data were collected and analyzed in 47 patients with infantile-onset disorder. RESULTS: Paroxysmal non-epileptic events (PNEE) were observed in 68% of infants, with paroxysmal tonic upward gaze (PTU) noticed in 47% of infants. Congenital cerebellar ataxia (CCA) was diagnosed in 51% of patients including four patients with developmental delay and only one neurological sign. PNEEs were found in 63% of patients at follow-up, with episodic ataxia (EA) in 40% of the sample. Cerebellar ataxia was found in 58% of the patients at follow-up. Four patients had epilepsy in infancy and nine in childhood. Seven infants had febrile convulsions, three of which developed epilepsy later; all three patients had CCA. Cognitive difficulties were demonstrated in 70% of the children. Cerebellar atrophy was found in only one infant but was depicted in 64% of MRIs after age two. CONCLUSIONS: Nearly all of the infants had CCA, PNEE or both. Cognitive difficulties were frequent and appeared to be associated with CCA. Epilepsy was more frequent after age two. Febrile convulsions in association with CCA may indicate risk of epilepsy in later childhood. Brain MRI was normal in infancy. There were no genotype-phenotype correlations found

Photoreceptor Guanylate Cyclase (GUCY2D) Mutations Cause Retinal Dystrophies by Severe Malfunction of Ca2+-Dependent Cyclic GMP Synthesis

Over 100 mutations in GUCY2D that encodes the photoreceptor guanylate cyclase GC-E are known to cause two major diseases: autosomal recessive Leber congenital amaurosis (arLCA) or autosomal dominant cone-rod dystrophy (adCRD) with a poorly understood mechanism at the molecular level in most cases. Only few mutations were further characterized for their enzymatic and molecular properties. GC-E activity is under control of neuronal Ca2+-sensor proteins, which is often a possible route to dysfunction. We investigated five recently-identified GC-E mutants that have been reported in patients suffering from arLCA (one large family) and adCRD/maculopathy (four families). Microsatellite analysis revealed that one of the mutations, c.2538G &gt; C (p.K846N), occurred de novo. To better understand the mechanism by which mutations that are located in different GC-E domains develop different phenotypes, we investigated the molecular consequences of these mutations by expressing wildtype and mutant GC-E variants in HEK293 cells. Analyzing their general enzymatic behavior, their regulation by Ca2+ sensor proteins and retinal degeneration protein 3 (RD3) dimerization domain mutants (p.E841K and p.K846N) showed a shift in Ca2+-sensitive regulation by guanylate cyclase-activating proteins (GCAPs). Mutations in the cyclase catalytic domain led to a loss of enzyme function in the mutant p.P873R, but not in p.V902L. Instead, the p.V902L mutation increased the guanylate cyclase activity more than 20-fold showing a high GCAP independent activity and leading to a constitutively active mutant. This is the first mutation to be described affecting the GC-E catalytic core in a complete opposite way

Juvenile mucopolysaccharidosis plus disease caused by a missense mutation in VPS33A.

Funder: Cambridge Biomedical Research Centre supported by the National Institute of Health ResearchFunder: Global Challenges Research FundFunder: Medical Research CouncilFunder: Global Challenge Research Grant, Research England GCRFFunder: European Union's Horizon 2020 Research and Innovation Program under the Marie Sklodowska‐CurieA rare and fatal disease resembling mucopolysaccharidosis in infants, is caused by impaired intracellular endocytic trafficking due to deficiency of core components of the intracellular membrane-tethering protein complexes, HOPS, and CORVET. Whole exome sequencing identified a novel VPS33A mutation in a patient suffering from a variant form of mucopolysaccharidosis. Electron and confocal microscopy, immunoblotting, and glycosphingolipid trafficking experiments were undertaken to investigate the effects of the mutant VPS33A in patient-derived skin fibroblasts. We describe an attenuated juvenile form of VPS33A-related syndrome-mucopolysaccharidosis plus in a man who is homozygous for a hitherto unknown missense mutation (NM_022916.4: c.599 G>C; NP_075067.2:p. Arg200Pro) in a conserved region of the VPS33A gene. Urinary glycosaminoglycan (GAG) analysis revealed increased heparan, dermatan sulphates, and hyaluronic acid. We showed decreased abundance of VPS33A in patient derived fibroblasts and provided evidence that the p.Arg200Pro mutation leads to destablization of the protein and proteasomal degradation. As in the infantile form of mucopolysaccharidosis plus, the endocytic compartment in the fibroblasts also expanded-a phenomenon accompanied by increased endolysosomal acidification and impaired intracellular glycosphingolipid trafficking. Experimental treatment of the patient's cultured fibroblasts with the proteasome inhibitor, bortezomib, or exposure to an inhibitor of glucosylceramide synthesis, eliglustat, improved glycosphingolipid trafficking. To our knowledge this is the first report of an attenuated juvenile form of VPS33A insufficiency characterized by appreciable residual endosomal-lysosomal trafficking and a milder mucopolysaccharidosis plus than the disease in infants. Our findings expand the proof of concept of redeploying clinically approved drugs for therapeutic exploitation in patients with juvenile as well as infantile forms of mucopolysaccharidosis plus disease

Juvenile Mucopolysaccharidosis plus disease caused by a missense mutation in VPS33A.

A rare and fatal disease resembling mucopolysaccharidosis in infants, is caused by impaired intracellular endocytic trafficking due to deficiency of core components of the intracellular membrane-tethering protein complexes, HOPS and CORVET. Whole Exome Sequencing identified a novel VPS33A mutation in a patient suffering from a variant form of mucopolysaccharidosis. Electron and confocal microscopy, immunoblotting, and glycosphingolipid trafficking experiments were undertaken to investigate the effects of the mutant VPS33A in patient-derived skin fibroblasts. We describe an attenuated juvenile form of VPS33A-related syndrome - mucopolysaccharidosis plus in a man who is homozygous for a hitherto unknown missense mutation (NM_022916.4: c.599 G>C; NP_075067.2:p. Arg200Pro) in a conserved region of the VPS33A gene. Urinary glycosaminoglycan (GAG) analysis revealed increased heparan, dermatan sulphates and hyaluronic acid. We showed decreased abundance of VPS33A in patient derived fibroblasts and provided evidence that the p.Arg200Pro mutation leads to destabilisation of the protein and proteasomal degradation. As in the infantile form of mucopolysaccharidosis plus, the endocytic compartment in the fibroblasts also expanded - a phenomenon accompanied by increased endolysosomal acidification and impaired intracellular glycosphingolipid trafficking. Experimental treatment of the patient's cultured fibroblasts with the proteasome inhibitor, bortezomib, or exposure to an inhibitor of glucosylceramide synthesis, eliglustat, improved glycosphingolipid trafficking. To our knowledge this is the first report of an attenuated juvenile form of VPS33A insufficiency characterised by appreciable residual endosomal-lysosomal trafficking and a milder mucopolysaccharidosis plus than the disease in infants. Our findings expand the proof of concept of redeploying clinically approved drugs for therapeutic exploitation in patients with juvenile as well as infantile forms of mucopolysaccharidosis plus disease. This article is protected by copyright. All rights reserved

Major brain malformations: corpus callosum dysgenesis, agenesis of septum pellucidum and polymicrogyria in patients with BCORL1-related disorders

ObjectiveBCORL1, a transcriptional co-repressor, has a role in cortical migration, neuronal differentiation, maturation, and cerebellar development. We describe BCORL1 as a new genetic cause for major brain malformations.Methods and resultsWe report three patients from two unrelated families with neonatal onset intractable epilepsy and profound global developmental delay. Brain MRI of two siblings from the first family depicted hypoplastic corpus callosum and septal agenesis (ASP) in the older brother and unilateral perisylvian polymicrogyria (PMG) in the younger one. MRI of the patient from the second family demonstrated complete agenesis of corpus callosum (CC). Whole Exome Sequencing revealed a novel hemizygous variant in NM_021946.5 (BCORL1):c.796C&gt;T (p.Pro266Ser) in the two siblings from the first family and the NM_021946.5 (BCORL1): c.3376G&gt;A; p.Asp1126Asn variant in the patient from the second family, both variants inherited from healthy mothers. We reviewed the patients' charts and MRIs and compared the phenotype to the other published BCORL1-related cases. Brain malformations have not been previously described in association with the BCORL1 phenotype. We discuss the potential influence of BCORL1 on brain development.ConclusionsWe suggest that BCORL1 variants present with a spectrum of neurodevelopmental disorders and can lead to major brain malformations originating at different stages of fetal development. We suggest adding BCORL1 to the genetic causes of PMG, ASP, and CC dysgenesis