The Canadian Neuromuscular Disease Registry 2010-2019: A Decade of Facilitating Clinical Research Througha Nationwide, Pan-NeuromuscularDisease Registry.

We report the recruitment activities and outcomes of a multi-disease neuromuscular patient registry in Canada. The Canadian Neuromuscular Disease Registry (CNDR) registers individuals across Canada with a confirmed diagnosis of a neuromuscular disease. Diagnosis and contact information are collected across all diseases and detailed prospective data is collected for 5 specific diseases: Amyotrophic Lateral Sclerosis (ALS), Duchenne Muscular Dystrophy (DMD), Myotonic Dystrophy (DM), Limb Girdle Muscular Dystrophy (LGMD), and Spinal Muscular Atrophy (SMA). Since 2010, the CNDR has registered 4306 patients (1154 pediatric and 3148 adult) with 91 different neuromuscular diagnoses and has facilitated 125 projects (73 academic, 3 not-for-profit, 3 government, and 46 commercial) using registry data. In conclusion, the CNDR is an effective and productive pan-neuromuscular registry that has successfully facilitated a substantial number of studies over the past 10 years.

The GBA p.Trp378Gly mutation is a probable French-Canadian founder mutation causing Gaucher disease and synucleinopathies.

Biallelic GBA mutations cause Gaucher disease (GD), and heterozygous carriers are at risk for synucleinopathies. No founder GBA mutations in French-Canadians are known. GBA was fully sequenced using targeted next generation and Sanger sequencing in French-Canadian Parkinson disease (PD) patients (n = 436), rapid eye movement (REM)-sleep behavior disorder (RBD) patients (n = 189) and controls (n = 891). Haplotype, identity-by-descent (IBD) and principal component analyses (PCA) were performed using single nucleotide polymorphism-chip data. Data on GD patients from Toronto and Montreal were collected from patients' files. A GBA p.Trp378Gly mutation was identified in two RBD and four PD patients (1% of all patients combined), and not in controls. The two RBD patients had converted to DLB within 3 years of their diagnosis. Haplotype, IBD and PCA analysis demonstrated that this mutation is from a single founder. Out of 167 GD patients screened, 15 (9.0%) carried the p.Trp378Gly mutation, all in trans with p.Asn370Ser. Three (20%) of the GD patients with the p.Trp378Gly mutation had developed Parkinsonism, and 11 patients had family history of PD. The p.Trp378Gly mutation is the first French-Canadian founder GBA mutation to be described, which leads to synucleinopathies and to GD type 1 when in compound heterozygosity with p.Asn370Ser.

Multiprobe Study of the Solid Electrolyte Interphase on Silicon-Based Electrodes in Full-Cell Configuration.

The failure mechanism of silicon-based electrodes has been studied only in a half-cell configuration so far. Here, a combination of 7Li, 19F MAS NMR, XPS, TOF-SIMS, and STEM-EELS, provides an in-depth characterization of the solid electrolyte interphase (SEI) formation on the surface of silicon and its evolution upon aging and cycling with LiNi1/3Mn1/3Co1/3O2 as the positive electrode in a full Li-ion cell configuration. This multiprobe approach indicates that the electrolyte degradation process observed in the case of full Li-ion cells exhibits many similarities to what has been observed in the case of half-cells in previous works, in particular during the early stages of the cycling. Like in the case of Si/Li half-cells, the development of the inorganic part of the SEI mostly occurs during the early stage of cycling while an incessant degradation of the organic solvents of the electrolyte occurs upon cycling. However, for extended cycling, all the lithium available for cycling is consumed because of parasitic reactions and is either trapped in an intermediate part of the SEI or in the electrolyte. This nevertheless does not prevent the further degradation of the organic electrolyte solvents, leading to the formation of lithium-free organic degradation products at the extreme surface of the SEI. At this point, without any available lithium left, the cell cannot function properly anymore. Cycled positive and negative electrodes do not show any sign of particles disconnection or clogging of their porosity by electrolyte degradation products and can still function in half-cell configuration. The failure mechanism for full Li-ion cells appears then very different from that known for half-cells and is clearly due to a lack of cyclable lithium because of parasitic reactions occurring before the accumulation of electrolyte degradation products clogs the porosity of the composite electrode or disconnects the active material particles.

Destructuring ionic liquids in ionogels: enhanced fragility for solid devices.

Confining ionic liquids (ILs) with added lithium salt within silica host networks enhances their fragility and improves their conductivity. Overall, conductivity measurements, Raman spectroscopy of the TFSI anion and NMR spectroscopy of the lithium cation show segregative interaction of lithium ions with the SiO2 host matrix. This implies at IL/SiO2 interfaces a breakdown of aggregated regions that are found systematically in bulk ILs. Such destructuration due to the interface effect determines the fragility and thus results locally at the interface in short relaxation times, low viscosity, and good ionic conductivity. The "destructuration" of ion pairs or domains makes ILs within ionogels a competitive alternative to existing solid ionic conductors in all-solid devices, such as lithium batteries and supercapacitors.

Effects of vine water status on dimethyl sulfur potential, ammonium, and amino acid contents in Grenache Noir grapes (Vitis vinifera).

We studied the effect of vine water status on the dimethyl sulfur potential (DMSP), ammonium, and amino acid contents of the berry during the maturation of Grenache Noir grapes. Water deficit increased the accumulation of amino acids in berries and favored yeast assimilable amino nitrogen. Similarly, ammonium content was higher in berries from vines subjected to moderate water deficit. DMSP content followed the same trend as yeast assimilable amino acid content, with higher concentrations observed in the berries of vines subjected to water deficit. The high DMSP and yeast assimilable nitrogen contents of musts from vines subjected to water deficit resulted in a better preservation of DMSP during winemaking. The wines produced from these musts had a higher DMSP level and would therefore probably have a higher aroma shelf life, because the DMSP determines the rate of release of dimethyl sulfur during wine storage, and this compound enhances fruity notes.

Establishing a Canadian registry of patients with amyotrophic lateral sclerosis.

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is a devastating cause of progressive weakness, respiratory failure and death. To date there is no effective therapy to meaningfully extend survival but continuously emerging targets and putative treatments are studied in clinical trials. Canadian epidemiological data on ALS is scarce and the socioeconomic impact of ALS on Canadian society is unclear. The Canadian Neuromuscular Disease Registry (CNDR) is a national clinic-based registry of patients with neuromuscular diseases with the goal of facilitating the design and execution of clinical research. METHODS: We conducted a national stakeholder survey to assess interest for a Canadian ALS registry and an assessment of expected case ascertainment. A dataset derivation meeting was held to establish the registry medical dataset. RESULTS: We report the results of the national stakeholder survey, case ascertainment assessment, and the derived dataset that have resulted in the current implementation of a Canadian registry of patients with ALS. CONCLUSIONS: The development of this long sought-after resource is a significant step forward for the Canadian ALS patient and research communities that will result in more efficient clinical trial recruitment and advancements in our understanding of ALS in Canada.

Diversity of ARSACS mutations in French-Canadians.

BACKGROUND: The growing number of spastic ataxia of Charlevoix-Saguenay (SACS) gene mutations reported worldwide has broadened the clinical phenotype of autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS). The identification of Quebec ARSACS cases without two known SACS mutation led to the development of a multi-modal genomic strategy to uncover mutations in this large gene and explore phenotype variability. METHODS: Search for SACS mutations by combining various methods on 20 cases with a classical French-Canadian ARSACS phenotype without two mutations and a group of 104 sporadic or recessive spastic ataxia cases of unknown cause. Western blot on lymphoblast protein from cases with different genotypes was probed to establish if they still expressed sacsin. RESULTS: A total of 12 mutations, including 7 novels, were uncovered in Quebec ARSACS cases. The screening of 104 spastic ataxia cases of unknown cause for 98 SACS mutations did not uncover carriers of two mutations. Compounds heterozygotes for one missense SACS mutation were found to minimally express sacsin. CONCLUSIONS: The large number of SACS mutations present even in Quebec suggests that the size of the gene alone may explain the great genotypic diversity. This study does not support an expanding ARSACS phenotype in the French-Canadian population. Most mutations lead to loss of function, though phenotypic variability in other populations may reflect partial loss of function with preservation of some sacsin expression. Our results also highlight the challenge of SACS mutation screening and the necessity to develop new generation sequencing methods to ensure low cost complete gene sequencing.

Quantitative MAS NMR characterization of the LiMn(1/2)Ni(1/2)O(2) electrode/electrolyte interphase.

The conditions in which degradation processes at the positive electrode/electrolyte interface occur are still incompletely understood and traditional surface analytical techniques struggle to characterize and depict accurately interfacial films. In the present work, information on the growth and evolution of the interphases upon storage and cycling as well as their electrochemical consequences are gathered in the case of LiNi(1/2)Mn(1/2)O(2) with commonly used LiPF(6) (1M in EC/DMC) electrolyte. The use of (7)Li, (19)F and (31)P MAS NMR, made quantitative through the implementation of empirical calibration, is combined with transmission electron microscopy (TEM) and electron energy loss spectroscopy (EELS) to probe the elements involved in surface species and to unravel the inhomogenous architecture of the interphase. At room temperature, contact with the electrolyte leads to a covering of the oxide surface first by LiF and lithiated organic species are found on the outer part of the interphase. At 55°C, not only the interphase proceeds in further covering of the surface but also thickens resulting in an increase of 240% of lithiated species and the presence of -POF(2) fluorophosphates. The composition gradient within the interphase depth is also strongly affected by the temperature. In agreement with the electrochemical performance, quantitative NMR surface analyses show that the use of LiBOB-modified electrolyte results in a Li-enriched interphase, intrinsically less resistive than the standard LiPF(6)-based interphase, comprised of a mixture of resistive LiF with non lithiated species.

Mutations in FUS cause FALS and SALS in French and French Canadian populations.

BACKGROUND: The identification of mutations in the TARDBP and more recently the identification of mutations in the FUS gene as the cause of amyotrophic lateral sclerosis (ALS) is providing the field with new insight about the mechanisms involved in this severe neurodegenerative disease. METHODS: To extend these recent genetic reports, we screened the entire gene in a cohort of 200 patients with ALS. An additional 285 patients with sporadic ALS were screened for variants in exon 15 for which mutations were previously reported. RESULTS: In total, 3 different mutations were identified in 4 different patients, including 1 3-bp deletion in exon 3 of a patient with sporadic ALS and 2 missense mutations in exon 15 of 1 patient with familial ALS and 2 patients with sporadic ALS. CONCLUSIONS: Our study identified sporadic patients with mutations in the FUS gene. The accumulation and description of different genes and mutations helps to develop a more comprehensive picture of the genetic events underlying amyotrophic lateral sclerosis.

Hematopoietic progenitor cell mobilization and harvesting in children with malignancies: do the advantages of pegfilgrastim really translate into clinical benefit?

Our purpose was to assess success rates in children of achieving optimal hematopoietic progenitor cells (HPCs) harvest after mobilization with 300 microg/kg pegfilgrastim. Between January 2005 and January 2007, 26 children with solid malignancies who were referred for HPC collection were consecutively included. Hematopoietic progenitor cell mobilization consisted of one s.c. injection of 300 microg/kg body weight (BW) of pegfilgrastim. The success criterion was defined as at least 5 x 10(6) CD34+ cells/kg during the first standard apheresis (less than 3 blood volumes processed (BVP)). After 26 inclusions, the Bayesian analysis gave a mean estimated success rate of 60.7% (95% credibility interval: 42.0-78.0%). The first apheresis allowed the collection of 8.3 x 10(6) CD34+ cells/kg BW (range 0.6-37.8), with a median of 2.8 BVP (range 1.4-3.0). Overall, the median of CD34+ cells collected was 12.4 x 10(6)/kg (range 2.7-37.8). The cumulative dose of anthracyclin was the only variable associated with the total number of CD34+ collected cells (P<0.05). Mobilization was clinically well tolerated in 20 patients. No drug-related adverse events of grade > or =3 occurred. We conclude that a single injection of 300 microg/kg pegfilgrastim in the hematological steady state is an efficient and well-tolerated method of HPC mobilization in children with solid malignancies.

Contribution of TARDBP mutations to sporadic amyotrophic lateral sclerosis.

AIMS AND BACKGROUND: Mutations in the TARDBP gene, which encodes the TAR DNA binding protein (TDP-43), have been described in individuals with familial and sporadic amyotrophic lateral sclerosis (ALS). We screened the TARDBP gene in 285 French sporadic ALS patients to assess the frequency of TARDBP mutations in ALS. RESULTS: Six individuals had potentially deleterious mutations of which three were novel including a Y374X truncating mutation and P363A and A382P missense mutations. This suggests that TARDBP mutations may predispose to ALS in approximately 2% of the individuals followed in this study. CONCLUSION: Our findings, combined with those from other collections, brings the total number of mutations in unrelated ALS patients to 17, further suggesting that mutations in the TARDBP gene have an important role in the pathogenesis of ALS.

Association of paraoxonase gene cluster polymorphisms with ALS in France, Quebec, and Sweden.

BACKGROUND: The paraoxonase gene cluster on chromosome 7 comprising the PON1-3 genes is an attractive candidate for association in amyotrophic lateral sclerosis (ALS) given the role of paraoxonase genes during the response to oxidative stress and their contribution to the enzymatic break down of nerve toxins. Oxidative stress is considered one of the mechanisms involved in ALS pathogenesis. Evidence for this includes the fact that mutations of SOD1, which normally reduce the production of toxic superoxide anion, account for 12% to 23% of familial cases in ALS. In addition, PON variants were shown to be associated with susceptibility to ALS in several North American and European populations. METHODS: We extended this analysis to examine 20 single nucleotide polymorphisms (SNPs) across the PON gene cluster in a set of patients from France (480 cases, 475 controls), Quebec (159 cases, 95 controls), and Sweden (558 cases, 506 controls). RESULTS: Although individual SNPs were not considered associated on their own, a haplotype of SNPs at the C-terminal portion of PON2 that includes the PON2 C311S amino acid change was significant in the French (p value 0.0075) and Quebec (p value 0.026) populations as well as all three populations combined (p value 1.69 x 10(-6)). Stratification of the samples showed that this variation was pertinent to ALS susceptibility as a whole, and not to a particular subset of patients. CONCLUSIONS: These findings contribute to the increasing weight of evidence that genetic variants in the paraoxonase gene cluster are associated with amyotrophic lateral sclerosis.

[Hereditary ataxias, spastic parapareses and neuropathies in Eastern Canada]. / Ataxies, paraparésies spastiques et neuropathies héréditaires fréquentes dans l'Est du Canada.

It has been demonstrated, for many inherited diseases, that historical events have shaped the various regional gene pools of Eastern Canada. In so doing, it has given rise to the increased prevalence of some rare diseases due, to founder effects. The following neurogenetic disorders were first identified in patients from Eastern Canada: AOA-2, Arsacs, HSN-2, Arca-1, HMSN/ACC and Arsal. The population of Eastern Canada, we are convinced, will still allow the identification of new rare forms of hereditary ataxias, spastic parapareses and neuropathies as well as contribute to the uncovering of their mutated genes. We have summarized our current knowledge of the various hereditary ataxias, spastic parapareses and neuropathies in Eastern Canada. The study of the more common and homogenous features of these diseases has been largely completed.

A novel founder SCN4A mutation causes painful cold-induced myotonia in French-Canadians.

BACKGROUND: Myotonia is observed in classic congenital myotonia caused by CLCN1 mutations and in sodium-channel myotonia (SCM) due to SCN4A mutations. METHODS: We assessed 66 electrically proven cases of myotonia belonging to 17 French-Canadian families living in the Saguenay Lac St-Jean area of Quebec, a region well known for its genetic founder effects. The CLCN1 gene was sequenced in one affected member of each family. SCN4A exons with known SCM mutations were subsequently sequenced in families where no CLCN1 mutations were found. RESULTS: Six families, 33% of cases (22/66), presenting classic congenital myotonia phenotypes were found to carry two previously identified CLCN1 mutations. In the other 11 families comprising 66% of cases (44/66), a new dominant SCN4A mutation in exon 24 (M1476I) was uncovered and segregated with a variable SCM phenotype. Although all carriers of this novel mutation had electrical myotonia, some were asymptomatic (25%) and age at onset was variable in the others (5 to 67, mean 21). Cold aggravated myotonia was observed in 41% of cases and painful myotonia in 18%. Additional features observed include aggravation of symptoms with pregnancies (7%), localized muscle swelling (2%), myotonic reactions to anesthesia (2%), and food-induced paralysis (2%). CONCLUSIONS: This cohort is the largest described with a variable sodium-channel myotonia phenotype caused by a single SCN4A mutation. The clinical variability observed in this cohort underlines the phenotypic heterogeneity of SCN4A mutations and suggests that variants in other genes likely modulate clinical expression.

Distal truncation of KCC3 in non-French Canadian HMSN/ACC families.

BACKGROUND: Hereditary motor and sensory neuropathy with agenesis of the corpus callosum (HMSN/ACC) is a severe and progressive autosomal recessive polyneuropathy. Mutations in the potassium-chloride cotransporter 3 gene (KCC3) were identified as responsible for HMSN/ACC in the French Canadian (FC) population. In the present study, the authors were interested in finding new mutations in non-FC populations, assessing the activity of mutant proteins and refining genotype-phenotype correlations. METHODS: The authors screened KCC3 for mutations using direct sequencing in six non-FC HMSN/ACC families. They then assessed the functionality of the most common mutant protein using a flux assay in Xenopus laevis oocytes. RESULTS: The authors identified mutations in exon 22 of KCC3: a novel mutation (del + 2994-3003; E1015X) in one family, as well as a known mutation (3031C-->T; R1011X) found in five unrelated families and associated with two different haplotypes. The function of the cotransporter was abolished, although a limited amount of mutant proteins were correctly localized at the membrane. CONCLUSIONS: KCC3 mutations in exon 22 constitute a recurrent mutation site for hereditary motor and sensory neuropathy with agenesis of the corpus callosum (HMSN/ACC), regardless of ethnic origin, and are the most common cause of HMSN/ACC in the non-French Canadian (FC) families analyzed so far. Therefore, for genetic analysis, exon 22 screening should be prioritized in non-FC populations. Finally, the R1011X mutation leads to the abrogation of KCC3's function in Xenopus laevis oocytes, likely due to impaired transit of the cotransporter.

A founder haplotype for autosomal dominant sensory ataxia in Eastern Canada.

We present phenotypic and genotypic data for an additional family with autosomal dominant sensory ataxia, a disease characterized by gait difficulties associated with diminished sensation in the limbs and areflexia. The same disease haplotype spanning the entire SNAX1 locus is observed in affected members of this second family, enabling the locus to be reduced to a 7.3-cM interval.

K-Cl cotransport in red blood cells from patients with KCC3 isoform mutants.

Red blood cells (RBCs) possess the K-Cl cotransport (KCC) isoforms 1, 3, and 4. Mutations within a given isoform may affect overall KCC activity. In a double-blind study, we analyzed, with Rb as a K congener, K fluxes (total flux, ouabain-sensitive Na+/K+ pump, and bumetanide-sensitive Na-K-2Cl cotransport, Cl-dependent, and ouabain- and bumetanide-insensitive KCC with or without stimulation by N-ethylmaleimide (NEM) and staurosporine or Mg removal, and basal channel-mediated fluxes, osmotic fragility, and ions and water in the RBCs of 8 controls, and of 8 patients with hereditary motor and sensory neuropathy with agenesis of corpus callosum (HMSN-ACC) with defined KCC3 mutations (813FsX813 and Phe529FsX532) involving the truncations of 338 and 619 C-terminal amino acids, respectively. Water and ion content and, with one exception, mean osmotic fragility, as well as K fluxes without stimulating agents, were similar in controls and HMSN-ACC RBCs. However, the NEM-stimulated KCC was reduced 5-fold (p < 0.0005) in HMSN-ACC vs control RBCs, as a result of a lower Vmax (p < 0.05) rather than a lower Km (p = 0.109), accompanied by corresponding differences in Cl activation. Low intracellular Mg activated KCC in 6 out of 7 controls vs 1 out of 6 HMSN-ACC RBCs, suggesting that regulation is compromised. The lack of differences in staurosporine-activated KCC indicates different action mechanisms. Thus, in HMSN-ACC patients with KCC3 mutants, RBC KCC activity, although indistinguishable from that of the control group, responded differently to biochemical stressors, such as thiol alkylation or Mg removal, thereby indirectly indicating an important contribution of KCC3 to overall KCC function and regulation.

Mutational spectrum of the CHAC gene in patients with chorea-acanthocytosis.

Chorea-acanthocytosis (ChAc) is an autosomal recessive neurological disorder whose characteristic features include hyperkinetic movements and abnormal red blood cell morphology. Mutations in the CHAC gene on 9q21 were recently found to cause chorea-acanthocytosis. CHAC encodes a large, novel protein with a yeast homologue implicated in protein sorting. In this study, all 73 exons plus flanking intronic sequence in CHAC were screened for mutations by denaturing high-performance liquid chromatography in 43 probands with ChAc. We identified 57 different mutations, 54 of which have not previously been reported, in 39 probands. The novel mutations comprise 15 nonsense, 22 insertion/deletion, 15 splice-site and two missense mutations and are distributed throughout the CHAC gene. Three mutations were found in multiple families within this or our previous study. The preponderance of mutations that are predicted to cause absence of gene product is consistent with the recessive inheritance of this disease. The high proportion of splice-site mutations found is probably a reflection of the large number of exons that comprise the CHAC gene. The CHAC protein product, chorein, appears to have a certain tolerance to amino-acid substitutions since only two out of nine substitutions described here appear to be pathogenic.

A founder mutation in French-Canadian families with X-linked hereditary neuropathy.

BACKGROUND: The aim of the present study was to identify the mutations in the connexin 32 gene in French-Canadian families with X-linked Charcot-Marie-Tooth disease (CMTX). METHODS: Molecular analysis was performed by nonisotopic single strand conformation polymorphism (SSCP) analysis and sequencing. Clinical evaluation was carried out according to the scale defined by the European Hereditary Motor and Sensory Neuropathy Consortium. RESULTS: In one family, the mutation Arg142Trp was located in the transmembrane domain III whereas, in four other families we identified a novel mutation (Ser26Trp) located in the transmembrane domain I of the connexin 32 gene. Haplotype analysis revealed that these four families are related and suggests a founder mutation. Sixteen patients from these four families were studied. As expected, all the affected males were more clinically affected than the females and all affected patients exhibited some electrophysiological characteristics of demyelination. CONCLUSION: Our study suggests that the Ser26Trp mutation may cause a primary demyelinating neuropathy that is not associated with a specific clinical phenotype. We also find evidence that the majority of kindreds share a common ancestor.