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BackgroundDespite advances in next generation sequencing technologies, the identification of variants of uncertain significance (VUS) can often hinder definitive diagnosis in patients with complex neurodevelopmental disorders.ObjectiveThe objective of this study was to identify and characterize the underlying cause of disease in a family with two children with severe developmental delay associated with generalized dystonia and episodic status dystonicus, chorea, epilepsy, and cataracts.MethodsCandidate genes identified by autozygosity mapping and whole-exome sequencing were characterized using cellular and vertebrate model systems.ResultsHomozygous variants were found in three candidate genes: MED27, SLC6A7, and MPPE1. Although the patients had features of MED27-related disorder, the SLC6A7 and MPPE1 variants were functionally investigated. SLC6A7 variant in vitro overexpression caused decreased proline transport as a result of reduced cell-surface expression, and zebrafish knockdown of slc6a7 exhibited developmental delay and fragile motor neuron morphology that could not be rescued by L-proline transporter–G396S RNA. Lastly, patient fibroblasts displayed reduced cell-surface expression of glycophosphatidylinositol-anchored proteins linked to MPPE1 dysfunction.ConclusionsWe report a family harboring a homozygous MED27 variant with additional loss-of-function SLC6A7 and MPPE1 gene variants, which potentially contribute to a blended phenotype caused by multilocus pathogenic variants. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society

Purple membranes from the archaeon Halobacterium salinarum consist of 2D crystals of the light-driven proton pump bacteriorhodopsin, which convert photons into a proton gradient across the cell membrane. This functional feature and the structural rigidity make them appealing candidates for integration into biomimetic devices. To this end, and in order to carry out their function, purple membranes must be positioned in the correct orientation at the position of interest. Precise placement and control over the orientation of nanoscale objects still constitutes a formidable challenge. Here, it is shown that isolated purple membrane patches can be transported and positioned at predefined locations in nanofluidic confinement, with control over their orientation at the target sites. The transport is achieved through a rocking Brownian motor scheme, while the controlled deposition of the membranes is realized by engineering the surface potential of a fluid-filled nanofluidic slit. This controlled manipulation of purple membrane patches outlines a new pathway toward the integration of biological or other delicate supramolecular structures into top–down-fabricated patterns, for the assembly of nanoscale hybrid devices that serve as a light-driven source of (chemical) energy.

We investigated seven children from six families to expand the phenotypic spectrum associated with an early infantile epileptic encephalopathy caused by biallelic pathogenic variants in the phosphatidylinositol glycan anchor biosynthesis class Q (PIGQ) gene. The affected children were all identified by clinical or research exome sequencing. Clinical data, including EEGs and MRIs, was comprehensively reviewed and flow cytometry and transfection experiments were performed to investigate PIGQ function. Pathogenic biallelic PIGQ variants were associated with increased mortality. Epileptic seizures, axial hypotonia, developmental delay and multiple congenital anomalies were consistently observed. Seizure onset occurred between 2.5 months and 7 months of age and varied from treatable seizures to recurrent episodes of status epilepticus. Gastrointestinal issues were common and severe, two affected individuals had midgut volvulus requiring surgical correction. Cardiac anomalies including arrythmias were observed. Flow cytometry using granulocytes and fibroblasts from affected individuals showed reduced expression of glycosylphosphatidylinositol (GPI)‐anchored proteins. Transfection of wildtype PIGQ cDNA into patient fibroblasts rescued this phenotype. We expand the phenotypic spectrum of PIGQ‐related disease and provide the first functional evidence in human cells of defective GPI‐anchoring due to pathogenic variants in PIGQ.

Background Osteochondritis dissecans is a condition wherein there is a subchondral bone lesion that causes pain, inflammation, and cartilage damage. Dominant Familial Osteochondritis Dissecans is a rare and severe form of osteochondritis dissecans (OCD). It is caused by heterozygous pathogenic variants in the gene encoding Aggrecan; ACAN. Aggrecan, a proteoglycan, is an essential component of the articular and growth plate cartilage. Methods Herein, we report three individuals from one family; the proband who presented with short stature, a lower limb bone exostosis, and bilateral knee and elbow OCD at the age of 13 years old. His twin brother presented with isolated short stature and his father with short stature and lumbar disc herniation. Results Next‐generation sequencing of the ACAN gene in the proband identified a frameshift variant which is also present in the brother and father with short stature. The proband was treated surgically with bilateral elbow microfracture, after the failure of conservative therapy. Conclusion To the best of our knowledge, this is the first patient with an aggrecanopathy who presents with osteochondritis dissecans due to a frameshift variant. This family presents with variable expressivity which might be attributed to modifier genes., Dominant Familial Osteochondritis Dissecans is a rare and severe form of osteochondritis dissecans (OCD). It is caused by heterozygous pathogenic variants in the gene encoding Aggrecan; ACAN. Herein, we report 3 individuals from one family; the proband who presented with short stature, a lower limb bone exostosis, and bilateral knee and elbow OCD at the age of 13 years old. Next‐generation sequencing of the ACAN gene in the proband identified a frameshift deletion and this variant was also present in the brother and father with short stature. To the best of our knowledge, this is the first patient with an aggrecanopathy who presents with osteochondritis dissecans due to a frameshift mutation.

During development, neurons extend axons toward their appropriate synaptic targets to establish functional neuronal connections. The growth cone, a highly motile structure at the tip of the axon, is capable of recognizing extracellular guidance cues and translating them into directed axon outgrowth through modulation of the actin cytoskeleton. Netrin-1 mediates its attractive function through the receptor deleted in colorectal cancer (DCC) to promote axon outgrowth and guidance. The calcium-activated protease calpain is involved in the cleavage of cytoskeletal proteins, which plays an important role during adhesion turnover and cell migration. However, its function during neuronal development is less understood. Here we demonstrate that netrin-1 activated calpain in embryonic rat cortical neurons in an extracellular-regulated kinase 1/2-dependent manner. In addition, we found that netrin-1 stimulation led to an increase in calpain-1 localization in the axon, whereas its endogenous inhibitor calpastatin was decreased in the growth cones of cortical neurons by indirect immunofluorescence. Interestingly, calpain-1 was able to cleave DCC in vitro. Furthermore, netrin-1 induced the cleavage of the cytoskeletal proteins spectrin and focal adhesion kinase concomitantly with the intracellular domain of DCC in a calpain-dependent manner in embryonic rat cortical neurons. Cortical neurons over-expressing calpastatin or calpain-depleted neurons displayed increased basal axon length and were unresponsive to netrin-1 stimulation. Altogether, we propose a novel model whereby netrin-1/DCC-mediated axon outgrowth is modulated by calpain-mediated proteolysis of DCC and cytoskeletal targets in embryonic cortical neurons. Open Science: This manuscript was awarded with the Open Materials Badge For more information see: https://cos.io/our-services/open-science-badges/.

Phosphatidylinositol Glycan Anchor Biosynthesis class H (PIGH) is an essential player in the glycosylphosphatidylinositol (GPI) synthesis, an anchor for numerous cell membrane‐bound proteins. PIGH deficiency is a newly described and rare disorder associated with developmental delay, seizures and behavioral difficulties. Herein, we report three new unrelated families with two different bi‐allelic PIGH variants, including one new variant p.(Arg163Trp) which seems associated with a more severe phenotype. The common clinical features in all affected individuals are developmental delay/intellectual disability and hypotonia. Variable clinical features include seizures, autism spectrum disorder, apraxia, severe language delay, dysarthria, feeding difficulties, facial dysmorphisms, microcephaly, strabismus, and musculoskeletal anomalies. The two siblings homozygous for the p.(Arg163Trp) variant have severe symptoms including profound psychomotor retardation, intractable seizures, multiple bone fractures, scoliosis, loss of independent ambulation, and delayed myelination on brain MRI. Serum iron levels were significantly elevated in one individual. All tested individuals with PIGH deficiency had normal alkaline phosphatase and CD16, a GPI‐anchored protein (GPI‐AP), was found to be decreased by 60% on granulocytes from one individual. This study expands the PIGH deficiency phenotype range toward the severe end of the spectrum with the identification of a novel pathogenic variant., GPIs are synthetized by the GPI‐GnT, comprising PIGH, on the cytoplasmic membrane of ER from a phosphatidylinositol and a N‐acetylglucosamine. Once flipped to the luminal side of the ER and further synthesized, GPIs are added to proteins to form GPI‐APs. GPI‐APs are transported to the cytoplasmic membrane via the Golgi. Features of individuals with bi‐allelic PIGH variants are presented according to their frequency.

Background Splicing is crucial for proper gene expression, and is predominately executed by the major spliceosome. Conversely, 722 introns in 699 human minor intron‐containing genes (MIGs) are spliced by the minor spliceosome. Splicing of these minor introns is disrupted in diseases caused by pathogenic variants in the minor spliceosome, ultimately leading to the aberrant expression of a subset of these MIGs. However, the effect of variants in minor introns and MIGs on diseases remains unexplored. Methods Variants in MIGs and associated clinical manifestations were identified using ClinVar. The HPO database was then used to curate the related symptoms and affected organ systems. Results: We found pathogenic variants in 211 MIGs, which commonly resulted in intellectual disability, seizures and microcephaly. This revealed a subset of MIGs whose aberrant splicing may contribute to the pathogenesis of minor spliceosome‐related diseases. Moreover, we identified 51 pathogenic variants in minor intron splice sites that reduce the splice site strength and can induce alternative splicing. Conclusion These findings highlight that disrupted minor intron splicing has a broader impact on human diseases than previously appreciated. The hope is that this knowledge will aid in the development of therapeutic strategies that incorporate the minor intron splicing pathway., Pathogenic variants in minor spliceosome components result in disrupted splicing of minor introns and a wide range of symptoms affecting many organ systems. Here, we identified a subset of minor intron‐containing genes that may play a role in the pathogenesis of these minor spliceosome‐related diseases. Moreover, we report the presence of 51 pathogenic variants in minor intron splice sites that result in a reduced splice site strength.

Worldwide, one in five men aged over 50 years will experience osteoporosis or a clinical bone fracture, with a greater fracture‐related mortality rate than women. However, the genetic etiology of osteoporosis in men is still poorly understood. We aimed to identify the genetic variants and candidate genes associated with extremely low or high BMD for a better understanding of the biology underlying low bone density that may point to potential therapeutic targets for increasing bone mass. Subjects from the Osteoporotic Fractures in Men Study (MrOS) cohort were evaluated by age and BMI‐adjusted total hip BMD. Those with BMD values 3 SDs away from the mean were selected and the remaining individuals whose adjusted BMD ranked at the highest or lowest 100 were included. Men with the lowest adjusted BMD (N = 98) and highest adjusted BMD (N = 110) were chosen for exome sequencing. Controls (N = 82) were men of Northern and Western European descent from the US Utah population of the 1000 Genomes Project. Fisher's exact test was performed to compare low‐ or high‐BMD subjects with controls for single‐gene associations. Additionally, sets of candidate genes causative of heritable disorders of connective tissue, including osteogenesis imperfecta (OI) and Ehlers‐Danlos syndrome (EDS), were grouped for multigene and mutation burden analyses. No single‐gene associations with rare variants were found for either the low BMD group (33 genes) or high BMD group (18 genes). In the group of OI genes, we detected a significant threefold increased accumulation of rare variants in low‐BMD subjects compared with controls (p = 0.009). Additionally, genes associated with EDS had a twofold increased frequency in low‐BMD subjects compared with controls (p = 0.03). These findings reveal a rare variant burden in OI and EDS disease genes at low BMD, which suggests a potential gene‐panel approach to screen for multivariant associations in larger cohorts. © 2019 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

Congenital disorders of glycosylation (CDGs) affect multiple systems and present a broad spectrum of clinical features, often including skeletal dysplasia. Exome sequencing has led to the identification of new CDG genes. Immune and skeletal phenotypes associated with mutations in PGM3, encoding a protein that converts N-acetyl-glucosamine-6-phosphate into N-acetyl-glucosamine-1-phosphate, were recently reported. Through exome sequencing, we identified a novel homozygous mutation (c.1135T>C; p.Phe379Leu) in PGM3 in two siblings with bone marrow failure, severe combined immunodeficiency, renal and intestinal malformations, and a skeletal dysplasia resembling Desbuquois dysplasia. Severe respiratory compromise secondary to lung hypoplasia and pulmonary hypertension, and intestinal obstruction led to their demise. We thus report the most severe phenotype described so far associated with PGM3 mutations. This CDG should be considered in the presence of skeletal dysplasia associated with severe immunodeficiency. © 2017 American Society for Bone and Mineral Research.

The group of chondrodysplasia with multiple dislocations includes several entities, characterized by short stature, dislocation of large joints, hand and/or vertebral anomalies. Other features, such as epiphyseal or metaphyseal changes, cleft palate, intellectual disability are also often part of the phenotype. In addition, several conditions with overlapping features are related to this group and broaden the spectrum. The majority of these disorders have been linked to pathogenic variants in genes encoding proteins implicated in the synthesis or sulfation of proteoglycans (PG). In a series of 30 patients with multiple dislocations, we have performed exome sequencing and subsequent targeted analysis of 15 genes, implicated in chondrodysplasia with multiple dislocations, and related conditions. We have identified causative pathogenic variants in 60% of patients (18/30); when a clinical diagnosis was suspected, this was molecularly confirmed in 53% of cases. Forty percent of patients remain without molecular etiology. Pathogenic variants in genes implicated in PG synthesis are of major importance in chondrodysplasia with multiple dislocations and related conditions. The combination of hand features, growth failure severity, radiological aspects of long bones and of vertebrae allowed discrimination among the different conditions. We propose key diagnostic clues to the clinician.

The most efficient drug against the human pathogenic fungus Pneumocystis jirovecii is cotrimoxazole targeting the folate biosynthesis. However, resistance toward it is emerging and adverse effects occur in some patients. Studies in rodent models suggested that echinocandins could be useful to treat Pneumocystis pneumonia. Echinocandins inhibit the catalytic subunit Gsc1 of the enzymatic complex ensuring the synthesis of 1,3-β glucan, an essential constituent of cell walls of most fungi. Besides, inhibitors of the enzyme Kre6 involved in the synthesis of 1,6-β glucan, another essential component of fungal walls, were recently described. We identified and functionally characterized these two potential drug targets in the human pathogen P. jirovecii by rescue of the null allele of the orthologous gene in Saccharomyces cerevisiae. The P. jirovecii proteins Gsc1 and Kre6 identified using those of the relative Pneumocystis carinii as the query sequence showed high sequence identity to the putative fungal orthologs (53-97% in conserved functional domains). The expression of their encoding genes on plasmid rescued the increased sensitivity to, respectively, caspofungin or calcofluor white of the corresponding S. cerevisiae null allele. The uniqueness and likely essentiality of these proteins suggest that they are potential good drug targets.

Spondylometaphyseal dysplasia (SMD) corner fracture type (also known as SMD "Sutcliffe" type, MIM 184255) is a rare skeletal dysplasia that presents with mild to moderate short stature, developmental coxa vara, mild platyspondyly, corner fracture-like lesions, and metaphyseal abnormalities with sparing of the epiphyses. The molecular basis for this disorder has yet to be clarified. We describe two patients with SMD corner fracture type and heterozygous pathogenic variants in COL2A1. These two cases together with a third case of SMD corner fracture type with a heterozygous COL2A1 pathogenic variant previously described suggest that this disorder overlaps with type II collagenopathies. The finding of one of the pathogenic variants in a previously reported case of spondyloepimetaphyseal dysplasia (SEMD) Strudwick type and the significant clinical similarity suggest an overlap between SMD corner fracture and SEMD Strudwick types. © 2016 Wiley Periodicals, Inc.

ispartof: ADVANCED MATERIALS INTERFACES vol:6 issue:15 status: published

This work reports on the first thin-film solid nanocomposite electrolyte (NCE) for lithium-ion batteries made by combining two gas-phase deposition techniques, molecular layer deposition (MLD) and atomic layer deposition (ALD). The advantage of using these techniques for the fabrication of NCEs comes from the ease of integration in thin-film batteries and the possibility to alter the properties of the oxide matrix and of the Li-compound independently. Moreover, the mesoporous oxide matrix based on an MLD and etching process, provides uniform interfaces with continuous conduction paths. An enhancement in Li-ion conductivity of two orders of magnitude, compared to the pure Li-compound, is obtained for an NCE consisting of a mesoporous Al2O3 matrix filled with Li2CO3. The impact of the oxide matrix on the resulting NCE Li-ion conductivity is considerable, showing four orders of magnitude difference between silica and alumina. Finally, integration of the NCE in a thin-film solid-state battery stack utilizing a Li-metal anode is demonstrated with good coulombic efficiency over a broad temperature range. The current findings and approach can expand the possibilities for development of novel thin-film solid-state electrolytes.