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The time required to reach a correct diagnosis is a key concern for rare disease (RD) patients. Diagnostic delay can be intolerably long, often described as an “odyssey” and, for some, a diagnosis may remain frustratingly elusive. The International Rare Disease Research Consortium proposed, as ultimate goal for 2017–2027, to enable all people with a suspected RD to be diagnosed within one year of presentation, if the disorder is known. Subsequently, unsolved cases would enter a globally coordinated diagnostic and research pipeline. In-depth analysis of the genotype through next generation sequencing, together with a standardized in-depth phenotype description and sophisticated high-throughput approaches, have been applied as diagnostic tools to increase the chance of a timely and accurate diagnosis. The success of this approach is evident in the Orphanet database. From 2010 to March 2017 over 600 new RDs and roughly 3600 linked genes have been described and identified. However, combination of -omics and phenotype data, as well as international sharing of this information, has raised ethical concerns. Values to be assessed include not only patient autonomy but also family implications, beneficence, non-maleficence, justice, solidarity and reciprocity, which must be respected and promoted and, at the same time, balanced among each other. In this work we suggest that, to maximize patients’ involvement in the search for a diagnosis and identification of new causative genes, undiagnosed patients should have the possibility to: (1) actively participate in the description of their phenotype; (2) choose the level of visibility of their profile in matchmaking databases; (3) express their preferences regarding return of new findings, in particular which level of Variant of Unknown Significance (VUS) significance should be considered relevant to them. The quality of the relationship between individual patients and physicians, and between the patient community and the scientific community, is critically important for optimizing the use of available data and enabling international collaboration in order to provide a diagnosis, and the attached support, to unsolved cases. The contribution of patients to collecting and coding data comprehensively is critical for efficient use of data downstream of data collection.

Rare diseases (RD) patient registries are powerful instruments that help develop clinical research, facilitate the planning of appropriate clinical trials, improve patient care, and support healthcare management. They constitute a key information system that supports the activities of European Reference Networks (ERNs) on rare diseases. A rapid proliferation of RD registries has occurred during the last years and there is a need to develop guidance for the minimum requirements, recommendations and standards necessary to maintain a high-quality registry. In response to these heterogeneities, in the framework of RD-Connect, a European platform connecting databases, registries, biobanks and clinical bioinformatics for rare disease research, we report on a list of recommendations, developed by a group of experts, including members of patient organizations, to be used as a framework for improving the quality of RD registries. This list includes aspects of governance, Findable, Accessible, Interoperable and Reusable (FAIR) data and information, infrastructure, documentation, training, and quality audit. The list is intended to be used by established as well as new RD registries. Further work includes the development of a toolkit to enable continuous assessment and improvement of their organizational and data quality. Supported by the RD-CONNECT: an integrated platform connecting registries, biobanks and clinical bioinformatics for rare disease research, which received funding from the European Union within the framework of FP7 Collaborative projectHEALTH.2012.2.1.1-1-C [Grant agreement number: 305444]. Supported partly also by EuRRECa: European Registries for Rare Endocrine Conditions, which received funding from the European Union within the framework of CHAFEA Health Programme (2014–2020) [Grant agreement number: 777215] and the COST Action CA16210 “Maximising Impact of research in NeuroDevelopmental Disorders”. Sí

The time required to reach a correct diagnosis is one of the most important problems for rare disease (RD) patients. Diagnostic delay can be intolerably long, to the point that it is usually described as a “diagnostic odyssey” and, sometimes, a diagnosis might never occur. The International Rare Disease Research Consortium proposed, as ultimate goal for 2017-2027, to enable all people with a suspected RD to be diagnosed within one year if the disorder is known, and to enter a globally coordinated diagnostic and research pipeline for the unsolved cases. In-depth analysis of the genotype through next generation sequencing, together with a standardized in-depth phenotype description and sophisticated high-throughput approaches, have been applied as diagnostic tools to increase the chance of a timely and accurate diagnosis. This approach is very fruitful as, according to the Orphanet database, from 2010 to March 2017 more than 600 new RDs have been described and about 3600 genes linked to RDs have been identified. However, combination of -omics and phenotype data and international sharing of this information raise ethical concerns. Values to be assessed include not only patient autonomy but also family implications, beneficence, non-maleficence, justice, solidarity and reciprocity, which must be respected and promoted and, at the same time, balanced among each other. In this work we suggest that, to maximise patients involvement in the search for a diagnosis and identification of new causative genes, undiagnosed patients should have the possibility to: 1) actively participate in the description of their phenotype; 2) choose the level of visibility of their profile in matchmaking databases; 3) express their preferences regarding return of new findings, in particular which level of Variant of Unknown Significance (VUS) significance should be considered relevant to them. The quality of the relation between individual patients and physicians, and between the patient community and the scientific community is critically important for making the best use of available data and combining efforts in the search for matches with similar cases worldwide that will help to solve unsolved cases. The contribution of patients to collecting and coding data comprehensively is critical for efficient use of data downstream of data collection.

Transgenic mouse models expressing mutant superoxide dismutase 1 (SOD1) have been critical in furthering our understanding of amyotrophic lateral sclerosis (ALS). However, such models generally overexpress the mutant protein, which may give rise to phenotypes not directly relevant to the disorder. Here, we have analysed a novel mouse model that has a point mutation in the endogenous mouse Sod1 gene; this mutation is identical to a pathological change in human familial ALS (fALS) which results in a D83G change in SOD1 protein. Homozgous Sod1(D83G/D83G) mice develop progressive degeneration of lower (LMN) and upper motor neurons, likely due to the same unknown toxic gain of function as occurs in human fALS cases, but intriguingly LMN cell death appears to stop in early adulthood and the mice do not become paralyzed. The D83 residue coordinates zinc binding, and the D83G mutation results in loss of dismutase activity and SOD1 protein instability. As a result, Sod1(D83G/D83G) mice also phenocopy the distal axonopathy and hepatocellular carcinoma found in Sod1 null mice (Sod1(-/-)). These unique mice allow us to further our understanding of ALS by separating the central motor neuron body degeneration and the peripheral effects from a fALS mutation expressed at endogenous levels.

Amyotrophic lateral sclerosis (ALS) is a fatal, neurodegenerative disorder in which motor neurons in the spinal cord and motor cortex degenerate. Although the majority of ALS cases are sporadic, mutations in Cu-Zn superoxide dismutase-1 (SOD1) are causative for 10-20% of familial ALS (fALS), and recent findings show that a hexanucleotide repeat expansion in the C9ORF72 gene may account for >30% of fALS cases in Europe. SOD1(G93A) transgenic mice have a phenotype and pathology similar to human ALS. In both ALS patients and SOD1(G93A) mice, the first pathological features of disease manifest at the neuromuscular junction, where significant denervation occurs prior to motor neuron degeneration. Strategies aimed at preventing or delaying denervation may therefore be of benefit in ALS. In this study, we show that Nogo-A levels increase in muscle fibres of SOD1(G93A) mice along with the elevation of markers of neuromuscular dysfunction (CHRNA1/MUSK). Symptomatic treatment of SOD1(G93A) mice from 70 days of age with an anti-Nogo-A antibody (GSK577548) significantly improves hindlimb muscle innervation at 90 days, a late symptomatic stage of disease, resulting in increased muscle force and motor unit survival and a significant increase in motor neuron survival. However, not all aspects of this improvement in anti-Nogo-A antibody-treated SOD1(G93A) mice were maintained at end-stage disease. These results show that treatment with anti-Nogo-A antibody significantly improves neuromuscular function in the SOD1(G93A) mouse model of ALS, at least during the earlier stages of disease and suggest that pharmacological inhibition of Nogo-A may be a disease-modifying approach in ALS.

Amyotrophic lateral sclerosis (ALS) is a debilitating and fatal late-onset neurodegenerative disease. Familial cases of ALS (FALS) constitute approximately 10% of all ALS cases, and mutant superoxide dismutase 1 (SOD1) is found in 15-20% of FALS. SOD1 mutations confer a toxic gain of unknown function to the protein that specifically targets the motor neurons in the cortex and the spinal cord. We have previously shown that the autosomal dominant Legs at odd angles (Loa) mutation in cytoplasmic dynein heavy chain (Dync1h1) delays disease onset and extends the life span of transgenic mice harboring human mutant SOD1(G93A). In this study we provide evidence that despite the lack of direct interactions between mutant SOD1 and either mutant or wild-type cytoplasmic dynein, the Loa mutation confers significant reductions in the amount of mutant SOD1 protein in the mitochondrial matrix. Moreover, we show that the Loa mutation ameliorates defects in mitochondrial respiration and membrane potential observed in SOD1(G93A) motor neuron mitochondria. These data suggest that the Loa mutation reduces the vulnerability of mitochondria to the toxic effects of mutant SOD1, leading to improved mitochondrial function in SOD1(G93A) motor neurons.

Optogenetics Applied to Motorneuron Control Nerves damaged by disease or injury do not always regenerate. In such cases, therapies involving transplanted stem cells show some promise. However, the new neurons derived from transplanted cells cannot communicate with the central control systems that would normally regulate movement. To avoid the need for such communication, in a proof-of-principle study, Bryson et al. (p. 94 ; see the Perspective by Iyer and Delp ) added optogenetic control to differentiation and transplantation of motor neurons. In the mouse, these engineered neurons were able to reestablish connections within a damaged sciatic nerve and, when activated by localized light stimulation, could drive muscle contractions.

Huntington’s disease is an autosomal dominant neurodegenerative disorder caused by the expansion of a polyglutamine repeat tract in the huntingtin protein. Polyglutamine-expanded huntingtin forms intranuclear as well as perinuclear inclusion bodies. Perinuclear aggregates formed by polyglutamine-expanded proteins are associated with a characteristic indentation of the nuclear envelope. We examined the nuclear envelope in cells containing huntingtin aggregates using immunostaining for lamin B1, a major component of the nuclear lamina. Laser confocal microscopy analysis revealed that huntingtin aggregates in a juxtanuclear position were associated with a clear focal distortion in the nuclear envelope in cells transfected with polyglutamine-expanded huntingtin. Lamin B1 distribution was not altered by aggregates of polyglutamine-expanded ataxin-1, that are exclusively intranuclear. Thus lamin immunocytochemistry demonstrates clearly the depression of the nuclear envelope resulting from the formation of perinuclear aggregates by polyglutamine-expanded huntingtin. Lamin immunocytochemistry would be of value to monitor the state of the nuclear envelope in experimental paradigms aimed at establishing the significance of perinuclear aggregates of pathogenic proteins.

Background: Since the discovery that mutations in the enzyme SOD1 are causative in human amyotrophic lateral sclerosis (ALS), many strategies have been employed to elucidate the toxic properties of this ubiquitously expressed mutant protein, including the generation of GFP-SOD1 chimaeric proteins for studies in protein localization by direct visualization using fluorescence microscopy. However, little is known about the biochemical and physical properties of these chimaeric proteins, and whether they behave similarly to their untagged SOD1 counterparts.Methodology/Principal Findings: Here we compare the physicochemical properties of SOD1 and the effects of GFP-tagging on its intracellular behaviour. Immunostaining demonstrated that SOD1 alone and GFP-SOD1 have an indistinguishable intracellular distribution in PC12 cells. Cultured primary motor neurons expressing GFP or GFP-SOD1 showed identical patterns of cytoplasmic expression and of movement within the axon. However, GFP tagging of SOD1 was found to alter some of the intrinsic properties of SOD1, including stability and specific activity. Evaluation of wildtype and mutant SOD1, tagged at either the N- or C-terminus with GFP, in PC12 cells demonstrated that some chimaeric proteins were degraded to the individual proteins, SOD1 and GFP.Conclusions/Significance: Our findings indicate that most, but not all, properties of SOD1 remain the same with a GFP tag.

SUMMARY Mutations in the enzyme glycyl-tRNA synthetase (GARS) cause motor and sensory axon loss in the peripheral nervous system in humans, described clinically as Charcot-Marie-Tooth type 2D or distal spinal muscular atrophy type V. Here, we characterise a new mouse mutant, GarsC201R, with a point mutation that leads to a non-conservative substitution within GARS. Heterozygous mice with a C3H genetic background have loss of grip strength, decreased motor flexibility and disruption of fine motor control; this relatively mild phenotype is more severe on a C57BL/6 background. Homozygous mutants have a highly deleterious set of features, including movement difficulties and death before weaning. Heterozygous animals have a reduction in axon diameter in peripheral nerves, slowing of nerve conduction and an alteration in the recovery cycle of myelinated axons, as well as innervation defects. An assessment of GARS levels showed increased protein in 15-day-old mice compared with controls; however, this increase was not observed in 3-month-old animals, indicating that GARS function may be more crucial in younger animals. We found that enzyme activity was not reduced detectably in heterozygotes at any age, but was diminished greatly in homozygous mice compared with controls; thus, homozygous animals may suffer from a partial loss of function. The GarsC201R mutation described here is a contribution to our understanding of the mechanism by which mutations in tRNA synthetases, which are fundamentally important, ubiquitously expressed enzymes, cause axonopathy in specific sets of neurons.