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A deficiency of 3-hydroxyisobutyric acid dehydrogenase (HIBADH) has been recently identified as a cause of primary 3-hydroxyisobutyric aciduria in two siblings; the only previously recognized primary cause had been a deficiency of methylmalonic semialdehyde dehydrogenase, the enzyme that is immediately downstream of HIBADH in the valine catabolic pathway and is encoded by the ALDH6A1 gene. Here we report on three additional patients from two unrelated families who present with marked and persistent elevations of urine L-3-hydroxyisobutyric acid (L-3HIBA) and a range of clinical findings. Molecular genetic analyses revealed novel, homozygous variants in the HIBADH gene that are private within each family. Evidence for pathogenicity of the identified variants is presented, including enzymatic deficiency of HIBADH in patient fibroblasts. This report describes new variants in HIBADH as an underlying cause of primary 3-hydroxyisobutyric aciduria and expands the clinical spectrum of this recently identified inborn error of valine metabolism. Additionally, we describe a quantitative method for the measurement of D- and L-3HIBA in plasma and urine and present the results of a valine restriction therapy in one of the patients.

In the field of rare diseases, progress in molecular diagnostics led to the recognition that variants linked to autosomal-dominant neurodegenerative diseases of later onset can, in the context of biallelic inheritance, cause devastating neurodevelopmental disorders and infantile or childhood-onset neurodegeneration. TOR1A-associated arthrogryposis multiplex congenita 5 (AMC5) is a rare neurodevelopmental disorder arising from biallelic variants in TOR1A, a gene that in the heterozygous state is associated to torsion dystonia-1 (DYT1 or DYT-TOR1A), an early-onset dystonia with reduced penetrance. While 15 individuals with TOR1A-AMC5 have been reported (less than 10 in detail), a systematic investigation of the full disease-associated spectrum has not been conducted. Here, we assess the clinical, radiological and molecular characteristics of 57 individuals from 40 families with biallelic variants in TOR1A. Median age at last follow-up was 3 years (0-24 years). Most individuals presented with severe congenital flexion contractures (95%) and variable developmental delay (79%). Motor symptoms were reported in 79% and included lower limb spasticity and pyramidal signs, as well as gait disturbances. Facial dysmorphism was an integral part of the phenotype, with key features being a broad/full nasal tip, narrowing of the forehead and full cheeks. Analysis of disease-associated manifestations delineated a phenotypic spectrum ranging from normal cognition and mild gait disturbance to congenital arthrogryposis, global developmental delay, intellectual disability, absent speech and inability to walk. In a subset, the presentation was consistent with fetal akinesia deformation sequence with severe intrauterine abnormalities. Survival was 71% with higher mortality in males. Death occurred at a median age of 1.2 months (1 week - 9 years) due to respiratory failure, cardiac arrest, or sepsis. Analysis of brain MRI studies identified non-specific neuroimaging features, including a hypoplastic corpus callosum (72%), foci of signal abnormality in the subcortical and periventricular white matter (55%), diffuse white matter volume loss (45%), mega cisterna magna (36%) and arachnoid cysts (27%). The molecular spectrum included 22 distinct variants, defining a mutational hotspot in the C-terminal domain of the Torsin-1A protein. Genotype-phenotype analysis revealed an association of missense variants in the 3-helix bundle domain to an attenuated phenotype, while missense variants near the Walker A/B motif as well as biallelic truncating variants were linked to early death. In summary, this systematic cross-sectional analysis of a large cohort of individuals with biallelic TOR1A variants across a wide age-range delineates the clinical and genetic spectrum of TOR1A-related autosomal-recessive disease and highlights potential predictors for disease severity and survival. CC BY 4.0Correspondence to: Reza MaroofianDepartment of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, London WC1N 3BG, UKE-mail: R.Maroofian@ucl.ac.ukA.S. is funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – SA 4171/1-1. H.H. is funded by The MRC (MR/S01165X/1, MR/S005021/1, G0601943), The National Institute for Health Research University College London Hospitals Biomedical Research Centre, Rosetree Trust, Ataxia UK, MSA Trust, Brain Research UK, Sparks GOSH Charity, Muscular Dystrophy UK (MDUK), Muscular Dystrophy Association (MDA USA). S.E. is supported by an MRC strategic award to establish an International Centre for Genomic Medicine in Neuromuscular Diseases (ICGNMD) MR/S005021/1’. This work was supported in part by the US National Institutes of Health R35 NS105078 and MDA#512848 to J.R.L., a jointly funded National Human Genome Research Institute (NHGRI) and National Heart, Lung, and Blood Institute (NHLBI) grant to the Baylor-Hopkins Center for Mendelian Genomics (UM1 HG006542) and NHGRI Genomics Research to Elucidate Genetics of Rare (BCM-GREGoR U01 HG011758). D.P. is supported by Clinical Research Training Scholarship in Neuromuscular Disease partnered by the American Brain Foundation (ABF) and Muscle Study Group (MSG). The research conducted at the Murdoch Children’s Research Institute was supported by the Victorian Government’s Operational Infrastructure Support Program. The Chair in Genomic Medicine awarded to J.C. is generously supported by The Royal Children’s Hospital Foundation. H.T. has been supported by the European Union’s Seventh Framework Program for research, technological development and demonstration under grant agreement no. 608473. H.S.D. is supported by the Cologne Clinician Scientist Program/Faculty of Medicine/University of Cologne and funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation, Project No. 413543196). H.J. has been supported by a grant from the European Union (H2020- MSCA-ITN-2017). A.M.D. is supported by the Eunice Kennedy Shriver National Institute of Child Health and Human Development of the National Institutes of Health (grant 1R01HD104938-01A1). H.L. receives support from the Canadian Institutes of Health Research (Foundation Grant FDN-167281), the Canadian Institutes of Health Research and Muscular Dystrophy Canada (Network Catalyst Grant for NMD4C), the Canada Foundation for Innovation (CFI-JELF 38412), and the Canada Research Chairs program (Canada Research Chair in Neuromuscular Genomics and Health, 950-232279). This research was funded in part by the Wellcome Trust (WT093205MA, WT104033AIA and the Synaptopathies Strategic Award, 165908) as well as the Medical Research Council (MRC) (MR/S01165X/1, MR/ S005021/1, G0601943). Additonally, we are grateful for funding from The MSA Trust, The National Institute for Health Research University College London Hospitals Biomedical Research Centre, The Michael J Fox Foundation (MJFF), BBSRC, The Fidelity Trust, Rosetrees Trust, Ataxia UK, Brain Research UK, Sparks GOSH Charity, Alzheimer’s Research UK (ARUK) and CureDRPLA.

Ambroxol hydrochloride is an oral mucolytic drug available over-the-counter for many years as cough medicine. In 2009 it was identified as a pharmacological chaperone for mutant glucocerebrosidase, albeit in a several-fold higher dose. Unfortunately, there have been no pharma-driven clinical trials to establish its use. Thus, real-world observational data are needed on the safety and efficacy of ambroxol for patients with Gaucher disease (GD) and GBA-Parkinson disease (GBA-PD). Clinicians treating patients with ambroxol for GD and GBA-PD were approached to collaborate in an investigator-initiated registry. Anonymized data were collected, including demographics, GD type, GD-specific therapy (when applicable), adverse events (AEs), and, when available, efficacy data. We report the data of the first 41 patients (25 females) at a median (range) age 17 (1.5-74) from 13 centers; 11 with GD type 1(four diagnosed with PD), 27 with neuronopathic GD (nGD), and three GBA mutation carriers with PD. The median (range) treatment period and maximum dose of ambroxol were 19 (1-76) months and 435 (75-1485) mg/day, respectively. One patient with type 2 GD died of her disease. No other severe AEs were reported. Twelve patients experienced AE, including minor bowel discomfort, cough, allergic reaction, mild proteinuria, dizziness and disease progression. Clinical benefits were reported in 25 patients, including stable or improved neurological status, increased physical activity, and reduced fatigue. Until the approval of specific therapies for nGD and disease-modification for GBA-PD, these preliminary data may be encouraging to physicians and patients who consider an off-label use of ambroxol.

Background and Objective Children with inherited metabolic diseases often require complex and highly specialized care. Patient and family-centered care can improve health outcomes that are important to families. This study aimed to examine experiences of family caregivers (parents/guardians) of children diagnosed with inherited metabolic diseases with healthcare to inform strategies to improve those experiences. Methods A cross-sectional mailed survey was conducted of family caregivers recruited from an ongoing cohort study. Participants rated their healthcare experiences during their child’s visits to five types of healthcare settings common for inherited metabolic diseases: the metabolic clinic, the emergency department, hospital inpatient units, the blood laboratory, and the pharmacy. Participants provided narrative descriptions of any memorable negative or positive experiences. Results There were 248 respondents (response rate 49%). Caregivers were generally very or somewhat satisfied with the care provided at each care setting. Appropriate treatment, provider knowledge, provider communication, and care coordination were deemed essential aspects of satisfaction with care by the majority of participants across many settings. Memorable negative experiences were reported by 8–22% of participants, varying by setting. Among participants who reported memorable negative experiences, contributing factors included providers’ demeanor, lack of communication, lack of involvement of the family, and disregard of an emergency protocol letter provided by the family. Conclusions While caregivers’ satisfaction with care for children with inherited metabolic diseases was high, we identified gaps in family-centered care and factors contributing to negative experiences that are important to consider in the future development of strategies to improve pediatric care for inherited metabolic diseases. Supplementary Information The online version contains supplementary material available at 10.1007/s40271-021-00538-8.

Central nervous system (CNS) abnormalities and corresponding neurological and psychiatric symptoms are frequently observed in lysosomal storage disorders (LSDs). The genetic background of individual LSDs is indeed unique to each illness. However, resulting defective lysosomal function within the CNS can transition normal cellular processes (i.e., autophagy) into aberrant mechanisms, facilitating overlapping downstream consequences including neurocircuitry dysfunction, neurodegeneration as well as sensory, motor, cognitive, and psychological symptoms. Here, the neurological and biobehavioral phenotypes of major classes of LSDs are discussed alongside therapeutic strategies in development that aim to tackle neuropathology among other disease elements. Finally, focused ultrasound blood-brain barrier opening is proposed to enhance therapeutic delivery thereby overcoming the key hurdle of central distribution of disease modifying therapies in LSDs.

We report on a 5‐year‐old female born to consanguineous parents, ascertained at the age of 23 months for an elevated plasma methionine level, a mildly abnormal total plasma homocysteine (tHcy), and elevated aminotransferases. She had global developmental delay, microcephaly, dysmorphic facial features, hypotonia, nystagmus and tremor in her upper extremities. Metabolic investigations demonstrated elevations in plasma methionine, plasma S‐adenosylmethionine (SAM) and plasma S‐adenosylhomocysteine (SAH), with normal urine adenosine levels. Some of the elevations persisted for over 1 year. Sequencing of the ADK and AHCY genes was negative for causative variants. Plasma methionine normalized 1 year after ascertainment, but SAM and SAH continued to be elevated for six more months before normalization, and aminotransferases remained mildly elevated. Whole exome sequencing demonstrated a homozygous pathogenic variant; {"type":"entrez-nucleotide","attrs":{"text":"NM_018297.3","term_id":"223941793","term_text":"NM_018297.3"}}NM_018297.3(NGLY1):c.1405C>T (p.Arg469*) in exon 9 of the NGLY1 gene, for which both parents were heterozygous. To our knowledge, this is the first report of NGLY1 deficiency with elevations in plasma methionine, SAM and SAH and a slight elevation of tHcy. Less than 20 patients have been reported with NGLY1 deficiency worldwide and this case expands on the biochemical phenotype of this newly discovered inborn error of metabolism.

The infantile spasms (IS) syndrome is a developmental epileptic encephalopathy disorder characterized by epileptic spasms occurring in infancy, hypsarrhythmia on the electroencephalography (EEG) and developmental arrest or regression. The etiologies include structural, metabolic, and genetic causes. We report an unusual case of IS due to a de novo variant in the MECP2 gene. The patient also had variants of uncertain significance in the SCN9A and SCN5A genes inherited from the father and mother, respectively. This report highlights the need for broad genetic testing in MECP2-related disorders with atypical presentations to better understand the disease etiology.

Several guidelines are available for identification and management of patients with Gaucher disease, but the most recent guideline was published in 2013. Since then, there have been significant advances in newborn screening, phenotypic characterization, identification of biomarkers and their integration into clinical practice, and the development and approval of new treatment options. Accordingly, the goal of this Delphi consensus exercise was to extend prior initiatives of this type by addressing issues related to newborn screening, diagnostic evaluations, and treatment (both disease directed and adjunctive). The iterative Delphi process involved creation of an initial slate of statements, review by a steering committee, and three rounds of consensus development by an independent panel. A preliminary set of statements was developed by the supporting agency based on literature searches covering the period from 1965 to 2020. The Delphi process reduced an initial set of 185 statements to 65 for which there was unanimous support from the panel. The statements supported may ultimately provide a framework for more detailed treatment guidelines. In addition, the statements for which unanimous support could not be achieved help to identify evidence gaps that are targets for future research.

Background and ObjectivesPurine-rich element-binding protein A (PURA) gene encodes Pur-α, a conserved protein essential for normal postnatal brain development. Recently, a PURA syndrome characterized by intellectual disability, hypotonia, epilepsy, and dysmorphic features was suggested. The aim of this study was to define and expand the phenotypic spectrum of PURA syndrome by collecting data, including EEG, from a large cohort of affected patients.MethodsData on unpublished and published cases were collected through the PURA Syndrome Foundation and the literature. Data on clinical, genetic, neuroimaging, and neurophysiologic features were obtained.ResultsA cohort of 142 patients was included. Characteristics of the PURA syndrome included neonatal hypotonia, feeding difficulties, and respiratory distress. Sixty percent of the patients developed epilepsy with myoclonic, generalized tonic-clonic, focal seizures, and/or epileptic spasms. EEG showed generalized, multifocal, or focal epileptic abnormalities. Lennox-Gastaut was the most common epilepsy syndrome. Drug refractoriness was common: 33.3% achieved seizure freedom. We found 97 pathogenic variants in PURA without any clear genotype-phenotype associations.DiscussionThe PURA syndrome presents with a developmental and epileptic encephalopathy with characteristics recognizable from neonatal age, which should prompt genetic screening. Sixty percent have drug-resistant epilepsy with focal or generalized seizures. We collected more than 90 pathogenic variants without observing overt genotype-phenotype associations.

Exome sequencing has identified COL5A1‐related Ehlers‐Danlos syndrome (MIM 130000) in a 15‐month‐old infant who resides in a Caribbean region where genetic services were previously not available. Due to the limited medical resources on the small Caribbean island where this child and her family reside, it is necessary to travel to a larger nearby island to access pediatric care. The parents were concerned about the child's extreme irritability and delayed developmental milestones. Physical examination revealed low muscle tone and diminished reflexes accompanied with failure to sustain eye contact, suggesting a neurological disorder. By fortuitous chance, a visiting clinical geneticist was able to examine the patient and noted velvety, doughy, slightly hyperextensible skin, and joint laxity. Exome sequencing of the family triad revealed that the child carried a novel de novo mutation in the Collagen, Type V, Alpha 1 (COL5A1) gene suggesting Ehlers‐Danlos syndrome (EDS). This diagnosis caused management to focus away from a neurological disorder and instead address issues related to defective collagen production. Now appropriate medical care has been implemented to monitor for possible cardiac manifestations as well as to address the musculoskeletal pain and poor muscle tone associated with this child's EDS. As permanent and visiting geneticists teaching at a medical school in the Caribbean, we realize that our expertise can be of great benefit to our community. We are assisting local and near by physicians who, because of geographical isolation and disparities in socioeconomic status, are unable to access medical genetic services. Our evolving role gives the physicians of this community the power to initiate appropriate therapies and suggest lifestyle modifications for some of their patients. One successful example of this practice lay with that of a 1‐year‐old baby girl with developmental delay who was suspected to have a form of autism, after exome sequencing received a correct diagnosis and treatment for Ehlers‐Danlos syndrome. Ehlers‐Danlos syndrome (EDS) is a group of heritable connective tissue disorders caused by a defect in collagen fibrils or collagen‐modifying enzymes.1 EDS is genetically and phenotypically heterogeneous with many clinical subtypes. The presentation of classical EDS (types I and the less severe type II, MIM#s 130000 and 130010, respectively) is due to formation of abnormal collagen fibers and includes joint laxity, aortic root dilation, and hyper extensible fragile skin. EDS patients also exhibit poor wound healing and subsequent formation of atrophic scars. In infants, classic EDS may manifest as low muscle tone and delay of developmental milestones such as sitting, standing, and walking.2 In the late 1970s, electron microscopy studies of skin biopsies from persons with classical EDS showed a disturbance in heterotypic collagen fibrils made of collagen types I and V. Notably, these fibrils were 13%‐40% larger in diameter with an irregular shape compared to controls.3 Almost two decades later, transgenic and linkage analysis studies provided evidence that EDS types I and II are linked to the components of type V collagen, namely COL5A1 and COL5A2.4, 5, 6, 7, 8, 9, 10 Quantitatively, type V collagen is a minor fibrillar collagen that is found in a variety of tissues. There are three gene products which can form three different versions of the fibril. The three genes, COL5A1, COL5A2, and COL5A3 encode proteins which can form either two heterotrimers ([α1(V)]2α2(V) or α1(V)α2(V)α3(V)) or a homotrimer ([α3(V)]3). More than half of the patients with classic EDS carry a mutation on either COL5A1 or COL5A2 genes. The most common type of mutation introduces a premature stop codon in the mRNA transcript which then leads to halpoinsufficiency of the peptide.11 There is no known cure for EDS and therapy is often multi‐layered, based on presenting features. Typically, children with classical EDS receive regular cardiac monitoring by electrocardiogram to monitor for aortic dilation and/or mitral valve prolapse, physiotherapy to assist with hypotonia and motor development, non‐weight‐bearing exercise to promote coordination and muscle strength, advice for treatment of wounds, and help to manage pain.

Patient involvement is increasingly recognized as critical to the development, introduction and use (i.e. the lifecycle) of new and effective therapies, particularly those for rare diseases, where natural histories and the impact on patients and families are less well-understood than for common diseases. However, little is known about how patients and families would like to be involved during the lifecycle. The aim of this study was to explore ways in which Canadian patients with rare diseases and their families would like to be involved in the lifecycle of therapies and identify their priorities for involvement. Patients with rare diseases and their families were recruited to participate in two deliberative sessions, during which concepts related to decision-making uncertainty and the technology lifecycle were introduced before eliciting input around ways in which they could be involved. This was followed by a webinar, which was used to further identify opportunities for involvement. The data were then analyzed qualitatively using eclectic coding. Patients and families identified opportunities that fell into three goals: (1) incorporation of their ‘lived experience’ in coverage decision making (i.e. decisions by governments on funding new therapies); (2) improved care for patients; and (3) greater awareness of rare diseases, with the first being a priority. Opportunities for patients and families to contribute their ‘lived experience’ are needed throughout the orphan drug lifecycle, but the ideal mechanisms for providing this input have yet to be determined.

Congenital disorders of glycosylation (CDG) are a group of metabolic diseases resulting from defects in glycan synthesis or processing. The number of subgroups and their phenotypic spectrums continue to expand with most related to deficiencies of N-glycosylation. ALG9-CDG (previously CDG-IL) is the result of a mutation in ALG9. This gene encodes the enzyme alpha-1,2-mannosyltransferase. To date, a total of 10 patients from 6 different families have been reported with one of four ALG9 mutations. Seven of these patients had a similar phenotype with failure to thrive, dysmorphic features, seizures, hepatic and/or renal cysts; the other three patients died in utero from a lethal skeletal dysplasia. This report describes an additional patient with ALG9-CDG who has a milder phenotype. This patient is a term female born to Caucasian, Canadian, non-consanguineous parents of Scottish decent. Prenatally, dysmorphic features, numerous renal cysts and minor cardiac malformations were detected. Post-natally, dysmorphic features included shallow orbits, micrognathia, hypoplastic nipples, talipes equinovarus, lipodystrophy and cutis marmorata. She developed failure to thrive and seizures. The metabolic work-up included analysis of a transferrin isoelectric focusing, which showed a type 1 pattern. This was confirmed by glycan profiling, which identified ahomozygous mutation in ALG9, c.860A > G (p.Tyr287Cys) (NM_1234567890). This had been previously published as a pathogenic mutation in two Canadian patients. Our goal is to contribute to the growing body of knowledge for this disorder by describing the phenotypic spectrum and providing further insight on prognosis.

Type 3 Gaucher disease (GD3) is characterized by progressive neurological features in addition to the typical systemic manifestations. Enzyme replacement therapy (ERT), the main stay treatment for Gaucher disease (GD), is not efficacious for the neurological manifestations. Ambroxol, in combination with ERT has been suggested to have potential as a promising therapy for patients with GD3. The purpose of this study is to assess the effect of Ambroxol on glucosylsphingosine (Lyso-Gb1) levels, and on the neurological morbidity, in two Canadian patients with GD3. Keywords: Ambroxol, Glucosylsphingosine, Gaucher, Ataxia, Epilepsy, Lyso-Gb1, Lyso-GL1

An improved understanding of diagnostic and treatment practices for patients with rare primary mitochondrial disorders can support benchmarking against guidelines and establish priorities for evaluative research. We aimed to describe physician care for patients with mitochondrial diseases in Canada, including variation in care.We conducted a cross-sectional survey of Canadian physicians involved in the diagnosis and/or ongoing care of patients with mitochondrial diseases. We used snowball sampling to identify potentially eligible participants, who were contacted by mail up to five times and invited to complete a questionnaire by mail or internet. The questionnaire addressed: personal experience in providing care for mitochondrial disorders; diagnostic and treatment practices; challenges in accessing tests or treatments; and views regarding research priorities.We received 58 survey responses (52% response rate). Most respondents (83%) reported spending 20% or less of their clinical practice time caring for patients with mitochondrial disorders. We identified important variation in diagnostic care, although assessments frequently reported as diagnostically helpful (e.g., brain magnetic resonance imaging, MRI/MR spectroscopy) were also recommended in published guidelines. Approximately half (49%) of participants would recommend "mitochondrial cocktails" for all or most patients, but we identified variation in responses regarding specific vitamins and cofactors. A majority of physicians recommended studies on the development of effective therapies as the top research priority.While Canadian physicians' views about diagnostic care and disease management are aligned with published recommendations, important variations in care reflect persistent areas of uncertainty and a need for empirical evidence to support and update standard protocols.Les soins de santé prodigués au Canada à des individus atteints de troubles mitochondriaux : une enquête menée auprès de médecins. Contexte: Dans le cas de patients atteints de troubles mitochondriaux rares, il est permis de croire qu’une meilleure compréhension des pratiques en matière de diagnostic et de traitement peut contribuer, au moyen des lignes directrices, à l’étalonnage et à l’établissement de priorités en ce qui regarde la recherche évaluative. Notre intention a été de décrire les soins prodigués au Canada par des médecins, notamment leur variabilité, dans le cas de ces patients. Méthodes: Pour ce faire, nous avons effectué une enquête transversale auprès de médecins canadiens qui posent des diagnostics de troubles mitochondriaux et qui prodiguent des soins continus aux patients qui en sont atteints. À cet effet, nous avons fait appel à la méthode d’enquête dite « en boule de neige » (snowball sampling) afin d’identifier des participants possiblement admissibles. Ces derniers ont été ensuite contactés par la poste, et ce, à cinq reprises au maximum. Ils ont été invités à remplir un questionnaire et à le retourner par la poste ou en ligne. Ce questionnaire abordait les aspects suivants : leur expérience personnelle à titre de prestataire de soins ; leurs pratiques en matière de diagnostic et de traitement ; les défis se présentant à eux au moment d’avoir accès à des tests ou à des traitements ; et finalement leurs points de vue en ce qui regarde les priorités de la recherche. Résultats: Dans le cadre de cette enquête, nous avons reçu 58 réponses, ce qui représente un taux de 52 %. Une majorité de répondants (83 %) ont indiqué allouer 20 % ou moins de leur temps de pratique clinique aux soins de patients atteints de ces troubles. Nous avons également noté d’importantes variations concernant les soins et les diagnostics, et ce, même si les outils d’évaluation fréquemment considérés utiles sur le plan diagnostic (p. ex. : des IRM du cerveau/la spectroscopie par RM) étaient également recommandés dans des lignes directrices déjà publiées. Environ la moitié de nos répondants (49 %) recommanderaient volontiers un « cocktail » de vitamines pour tous leurs patients ou la plupart d’entre eux. Quand il est question de vitamines spécifiques et de cofacteurs, nous avons cependant identifié une variation dans leurs réponses. Interrogés quant à la priorité numéro un en matière de recherche, une majorité de répondants a dit recommander la poursuite d’études portant sur la mise sur pied de traitements thérapeutiques efficaces. Conclusions: Bien que les points de vue de ces médecins canadiens en ce qui regarde les diagnostics et la prise en charge des troubles mitochondriaux soient en phase avec des recommandations publiées, d’importantes variations reflètent la persistance d’aspects incertains ainsi qu’un besoin de données empiriques afin de renforcer et de mettre à jour les protocoles de rééférence.

D-2-hydroxyglutaric aciduria is a rare neurometabolic condition with a variable clinical spectrum. Here we report on a patient with speech delay, ascertained for an elevated urine 2-hydroxyglutaric acid levels, and found to have a novel pathogenic homozygous deletion in D2HGDH (NG_012012.1(NM_152783.4):c.(292 + 1_293–1)_(*847_?)del). This case expands on the reported phenotype, with speech delay being the prominent clinical finding and despite identifying a large deletion in the D2HGDH gene, the patient presents with the mild phenotype. Keywords: 2-Hydroxyglutaric, Aciduria, D-2HGA, D2HGDH, Speech, Delay

International audience; We identified individuals with variations in ACTL6B, a component of the chromatin remodeling machinery including the BAF complex. Ten individuals harbored bi-allelic mutations and presented with global developmental delay, epileptic encephalopathy, and spasticity, and ten individuals with de novo heterozygous mutations displayed intellectual disability, ambulation deficits, severe language impairment, hypotonia, Rett-like stereotypies, and minor facial dysmorphisms (wide mouth, diastema, bulbous nose). Nine of these ten unrelated individuals had the identical de novo c.1027G>A (p.Gly343Arg) mutation. Human-derived neurons were generated that recaptured ACTL6B expression patterns in development from progenitor cell to post-mitotic neuron, validating the use of this model. Engineered knock-out of ACTL6B in wild-type human neurons resulted in profound deficits in dendrite development, a result recapitulated in two individuals with different bi-allelic mutations, and reversed on clonal genetic repair or exogenous expression of ACTL6B. Whole-transcriptome analyses and whole-genomic profiling of the BAF complex in wild-type and bi-allelic mutant ACTL6B neural progenitor cells and neurons revealed increased genomic binding of the BAF complex in ACTL6B mutants, with corresponding transcriptional changes in several genes including TPPP and FSCN1, suggesting that altered regulation of some cytoskeletal genes contribute to altered dendrite development. Assessment of bi-alleic and heterozygous ACTL6B mutations on an ACTL6B knock-out human background demonstrated that bi-allelic mutations mimic engineered deletion deficits while heterozygous mutations do not, suggesting that the former are loss of function and the latter are gain of function. These results reveal a role for ACTL6B in neurodevelopment and implicate another component of chromatin remodeling machinery in brain disease.

Introduction Reimbursement decisions on orphan drugs carry significant uncertainty, and as the amount increases, so does the risk of making a wrong decision, where harms outweigh benefits. Consequently, patients often face limited access to orphan drugs. Managed access programmes (MAPs) are a mechanism for managing risk while enabling access to potentially beneficial drugs. Patients and their caregivers have expressed support for these programmes and see patient input as critical to successful implementation. However, they have yet to be systematically involved in their design. Objective The aim of this study was to co-design with patients and caregivers a tool for the development of managed access programmes. Methods Building upon established relationships with the Canadian Organization for Rare Disorders, the project team collaborated with patients and caregivers using the principles of participatory action research. Data were collected at two workshops and analysed using a thematic network approach. Results Patients and caregivers co-designed a checklist comprised of six aspects of an ideal MAP relating to accountability (programme goals); governance (MAP-specific committee oversight, patient input, international collaboration); and evidence collection (outcome measures and continuation criteria, on-going monitoring and registries). They recognized that health-care resources are finite and considered disease or drug eligibility criteria for deciding when to use a MAP (eg drugs treating diseases for which there are no other legitimate alternatives). Conclusions A patient and caregiver-designed checklist was created, which emphasized patient involvement and transparency. Further research is needed to examine the feasibility of this checklist and roles for other stakeholders.

Pyridoxine-dependent epilepsy (PDE) is an epileptic encephalopathy characterized by response to pharmacologic doses of pyridoxine. PDE is caused by deficiency of alpha-aminoadipic semialdehyde dehydrogenase resulting in impaired lysine degradation and subsequent accumulation of alpha-aminoadipic semialdehyde. Despite adequate seizure control with pyridoxine monotherapy, 75% of individuals with PDE have significant developmental delay and intellectual disability. We describe a new combined therapeutic approach to reduce putative toxic metabolites from impaired lysine metabolism. This approach utilizes pyridoxine, a lysine-restricted diet to limit the substrate that leads to neurotoxic metabolite accumulation and L-arginine to compete for brain lysine influx and liver mitochondrial import. We report the developmental and biochemical outcome of six subjects who were treated with this triple therapy. Triple therapy reduced CSF, plasma, and urine biomarkers associated with neurotoxicity in PDE. The addition of arginine supplementation to children already treated with dietary lysine restriction and pyridoxine further reduced toxic metabolites, and in some subjects appeared to improve neurodevelopmental outcome. Dietary lysine restriction was associated with improved seizure control in one subject, and the addition of arginine supplementation increased the objective motor outcome scale in two twin siblings, illustrating the contribution of each component of this treatment combination. Optimal results were noted in the individual treated with triple therapy early in the course of the disease. Residual disease symptoms could be related to early injury suggested by initial MR imaging prior to initiation of treatment or from severe epilepsy prior to diagnosis. This observational study reports the use of triple therapy, which combines three effective components in this rare condition, and suggests that early diagnosis and treatment with this new triple therapy may ameliorate the cognitive impairment in POE. (C) 2015 Elsevier Inc. All rights reserved

Background Patients and their families have become more active in healthcare systems and research. The value of patient involvement is particularly relevant in the area of rare diseases, where patients face delayed diagnoses and limited access to effective therapies due to the high level of uncertainty in market approval and reimbursement decisions. It has been suggested that patient involvement may help to reduce some of these uncertainties. This review explored existing and proposed roles for patients, families, and patient organizations at each stage of the lifecycle of therapies for rare diseases (i.e., orphan drug lifecycle). Methods A scoping review was conducted using methods outlined by Arksey and O’Malley. To validate the findings from the literature and identify any additional opportunities that were missed, a consultative webinar was conducted with members of the Patient and Caregiver Liaison Group of a Canadian research network. Results Existing and proposed opportunities for involving patients, families, and patient organizations were reported throughout the orphan drug lifecycle and fell into 12 themes: research outside of clinical trials; clinical trials; patient reported outcomes measures; patient registries and biorepositories; education; advocacy and awareness; conferences and workshops; patient care and support; patient organization development; regulatory decision-making; and reimbursement decision-making. Existing opportunities were not described in sufficient detail to allow for the level of involvement to be assessed. Additionally, no information on the impact of involvement within specific opportunities was found. Based on feedback from patients and families, documentation of existing opportunities within Canada is poor. Conclusions Opportunities for patient, family, and patient organization involvement exist throughout the orphan drug lifecycle. However, based on the information found, it is not possible to determine which opportunities would be most effective at each stage. Electronic supplementary material The online version of this article (10.1186/s13023-017-0738-6) contains supplementary material, which is available to authorized users.

Glutaric aciduria type 3 (GA3) is associated with decreased conversion of free glutaric acid to glutaryl-coA, reflecting deficiency of succinate-hydroxymethylglutarate coA-transferase, caused by variants in the SUGCT (C7orf10) gene. GA3 remains less well known, characterised and understood than glutaric aciduria types 1 and 2. It is generally considered a likely "non-disease," but this is based on limited supporting information, with only nine individuals with GA3 described in the literature. Clinicians encountering a patient with GA3 therefore still face a dilemma of whether or not this should be dismissed as irrelevant.We have identified three unrelated Canadian patients with GA3. Two came to clinical attention because of symptoms, while the third was identified by a population urine-based newborn screening programme and has so far remained asymptomatic. We describe the clinical histories, biochemical characterisation and genotypes of these individuals. Examination of allele frequencies underlines the fact that GA3 is underdiagnosed. While one probable factor is that some GA3 patients remain asymptomatic, we highlight other plausible reasons whereby this diagnosis might be overlooked.Gastrointestinal disturbances were previously reported in some GA3 patients. In one of our patients, severe episodes of cyclic vomiting were the major problem. A trial of antibiotic treatment, to minimise bacterial GA production, was followed by significant clinical improvement.At present, there is insufficient evidence to define any specific clinical phenotype as attributable to GA3. However, we consider that it would be premature to assume that this condition is completely benign in all individuals at all times.

Larsen syndrome is a rare congenital disorder commonly associated with dysmorphic facies, large joint dislocations, equinovarus or equinovalgus foot deformities, and various hand anomalies, including supernumerary carpal bones. The authors present a case of Larsen syndrome with bilateral supernumerary carpal bones as the sole clinical manifestation. A literature review investigating skeletal anomalies in patients with Larsen syndrome was performed and revealed that the present case represents a unique presentation of this disorder, lacking all of the major clinical features previously described in the literature. An approach to patients with supernumerary carpal bones is discussed.

Background A high level of succinylacetone (SA) in blood is a sensitive, specific newborn screening marker for hepatorenal tyrosinemia type 1 (HT1, MIM 276700) caused by deficiency of fumarylacetoacetate hydrolase (FAH). Newborns with HT1 are usually clinically asymptomatic but show liver dysfunction with coagulation abnormalities (prolonged prothrombin time and/or high international normalised ratio). Early treatment with nitisinone (NTBC) plus dietary restriction of tyrosine and phenylalanine prevents the complications of severe liver disease and neurological crises. Methods and results Six newborns referred for hypersuccinylacetonaemia but who had normal coagulation testing on initial evaluation had sequence variants in the GSTZ1 gene, encoding maleylacetoacetate isomerase (MAAI), the enzyme preceding FAH in tyrosine degradation. Initial plasma SA levels ranged from 233 to 1282 nmol/L, greater than normal ( T (p.Ala150Val). One was compound heterozygous for c.259C>T (p.Arg87Ter) and an intronic sequence variant. In one, a single heterozygous GSTZ1 sequence variant was identified, c.295G>A (p.Val99Met). Bacterial expression of p.Ala150Val and p.Val99Met revealed low MAAI activity. The six individuals with mild hypersuccinylacetonaemia (MHSA) were not treated with diet or nitisinone. Their clinical course has been normal for up to 13 years. Conclusions MHSA can be caused by sequence variants in GSTZ1 . Such individuals have thus far remained asymptomatic despite receiving no specific treatment.

We report a male infant with 22q11.2 deletion syndrome and very severe multi-sutural craniosynostosis associated with increased intracranial pressure, marked displacement of brain structures, and extensive erosion of the skull. While uni- or bi-sultural craniosynostosis is a recognized (though relatively uncommon) feature of 22q11 deletion syndrome, a severe multi-sutural presentation of this nature has never been reported. SNP Microarray was otherwise normal and the patient did not have common mutations in FGFR2, FGFR3, or TWIST associated with craniosynostosis. While markedly variable expressivity is an acknowledged feature of deletion 22q11 syndrome, herein we also consider and discuss the possibility that this infant may have been additionally affected with an undiagnosed single gene disorder.

Background Late-onset Pompe disease (LOPD) is a rare treatable lysosomal storage disorder characterized by progressive lysosomal glycogen accumulation and muscle weakness, with often a limb-girdle pattern. Despite published guidelines, testing for LOPD is often overlooked or delayed in adults, owing to its low frequency compared to other muscle disorders with similar muscle patterns. Next-generation sequencing has the capability to test concurrently for several muscle disorders. This could potentially lead to increased diagnosis of LOPD, disorders with non-specific muscle weakness or atypical patients. Methods We developed a gene panel to further study its clinical utility in a cohort of patients with suspected muscle disorders. We designed a gene panel to analyze the coding sequences and splice site junctions of GAA causing LOPD, along with 77 other genes causing muscle disorders with overlapping phenotypes. Results At a median coverage of ~200X (sequences per base), all GAA exons were successfully covered with >20X and only 0.3 % of exons across all genes were

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Phagocytic cells such as polymorphonuclear neutrophils (PMNs) and monocytes play a key role in host defense against bacterial infection. During infection, phagocytic cell activity is modulated by cytokines (from the host) and toxins (from the invading microorganism). For example, after exposure to lipopolysaccharide (LPS), PMNs are primed for increased oxidative radical production (1, 45), and monocytes are activated to produce tumor necrosis factor alpha (TNF-α) (4, 35). Since priming of PMNs and activation of monocytes are key stages of the early response to infection, any altered or delayed response to LPS may interupt the host's response to infection. We have shown previously that PMNs from newborns are primed less effectively in vitro with LPS compared to PMNs from adults (7, 38). Similarly, some authors have found that monocytes from newborns have a lower response than adult monocytes in the secretion of cytokines, such as TNF-α, after LPS stimulation (11, 36). This diminished response to LPS by newborn monocytes and PMNs may contribute to the observed increased incidence and susceptibility of newborns to gram-negative bacterial infection (22, 42). Over the past decade the mechanism of LPS interaction with the phagocytic cell membrane has become more clearly understood. For adult PMNs, monocytes, and macrophages, CD14 is the principal cell membrane receptor for the LPS/LPS-binding protein (LBP) complex (40). Indeed, the presence of CD14 and LBP greatly enhance cellular activation with LPS (25, 27, 37, 41, 48, 50, 51, 54). In addition to CD14, a family of transmembrane receptors with homology to Toll proteins of Drosophila are known to trigger inflammatory reactions, including secretion of proinflammatory cytokines (32, 39). The Toll-like receptor-4 (TLR-4) imparts ligand-specific recognition of LPS for mammalian cells (18, 28). Through CD14-TLR-4 interactions, LPS induces several intracellular responses, including activation of nuclear factor κB (NF-κB) and activation of the mitogen-activated protein (MAP) kinase family, particularly extracellular-signal regulated kinases (ERKs) and p38 (49). However, the intracellular processes involved in TNF-α transcription, translation, and secretion into the extracellular space after stimulation by LPS are less well understood. Using an in vitro model of the mononuclear cell (MNC) response to LPS, Cohen et al. (11) showed that cells derived from cord blood of newborns secrete lower amounts of TNF-α compared to MNC from adults. A decreased response to LPS may be even more marked in preterm infants (17, 24). However, the mechanism underlying the hyporesponsiveness of newborn cells has not been determined. We hypothesized that newborn cells have an inherent deficiency in the production of TNF-α upon LPS stimulation. We investigated surface expression of CD14 and TLR-4 on adult and newborn monocytes and LPS-induced TNF-α secretion. We also compared intracellular factors in adult and newborn mononuclear cells, including myeloid differentiation antigen 88 (MyD88) and phosphorylation of ERK-1 and ERK-2 (ERK-1/2) and p38, as well as IκB phosphorylation and degradation. We report here that diminished LPS-induced TNF-α protein secretion by monocytes from human newborns is associated with diminished MyD88 expression.

Introduction:Reimbursement decisions on orphan drugs carry significant uncertainty, and as the amount increases, so does the risk of making a wrong decision, where harms outweigh benefits. Consequently, patients often face limited access to orphan drugs. Managed access programs (MAPs) are a mechanism for managing risk while enabling access to potentially beneficial drugs. Patients and their caregivers have expressed support for these programs and see patient input as critical to successful implementation. However, they have yet to be systematically involved in their design. The objective of this study was to explore what a framework for MAPs might look like when designed by patients and caregivers.Methods:Building upon established relationships with the Canadian Organization for Rare Disorders, the project team collaborated with patients and caregivers using the principles of participatory action research. Data were collected at two workshops and analyzed using a thematic network approach.Results:Patients and caregivers identified six aspects of an ideal MAP relating to accountability (program goals), governance (program-specific committee oversight; patient input; international collaboration), and evidence collection (outcome measures and stopping criteria; ongoing monitoring and registries). Additionally, patients and caregivers recognized that health care resources are finite and considered disease or drug eligibility criteria for deciding when to use a MAP (e.g. drugs treating diseases for which there are no other legitimate alternatives).Conclusions:A patient and caregiver-designed framework was created, which emphasized patient involvement and transparency. Further research is needed to examine the feasibility of this framework and roles for other stakeholders.

We report on a girl with trisomy 12 mosaicism diagnosed postnatally. She has been followed from 4 months of age for developmental delay, unilateral sensorineural hearing loss, intestinal malrotation, hemi-hyperplasia, pigmentary dysplasia, retinopathy, and a vascular ring. To our knowledge, there have been no reports of complete trisomy 12 in the literature. However there have been a few reports describing the phenotype of individuals with trisomy 12 mosaicism. This case report is a description of the eighth liveborn individual diagnosed postnatally with this condition.

We report on a patient with severe intellectual disability, microcephaly, short stature, and dysmorphic features who, based on standard karyotyping, has two cytogenetic abnormalities: an apparently balanced paracentric inversion of chromosome 7, inv(7)(q31.2q36), and a small supernumerary ring chromosome derived entirely of material from chromosome 19. While the inversion was detected in all cells, mosaicism was observed for the ring chromosome. Interestingly, apparently identical cytogenetic abnormalities were detected in the patient's mother, who presented with normal stature, few dysmorphic features, and normal cognition without microcephaly. While the level of mosaicism could not adequately explain the phenotypic discordance, comparative genome hybridization revealed a de novo terminal deletion of chromosome 7, del(7)(q36.2), and a terminal duplication of chromosome 7, dup(7)(p22.1) in the patient. Additional cytogenetic investigation revealed that the patient inherited a recombinant chromosome derived from a cryptic maternal pericentric inversion: inv(7)(p22q36). The patient's distinctive features are consistent with the wide phenotypic spectrum reported in 7p duplication and 7q terminal deletion syndromes. These chromosomal regions contain several candidate genes of clinical significance, including SHH, EN2, and FAM20C. Our findings strongly suggest that our patient's phenotype is largely attributable to partial 7pter trisomy and partial 7qter monosomy rather than mosaic supernumerary ring chromosome 19.

Objective Neurodevelopmental disorders (NDDs) are a large and complex group of disorders with varied etiologies. Recent advances in sequencing, induced stem cells, and small molecule screening technologies provide an opportunity to develop personalised treatment for NDDs. Methods The INVESTICATE project recruits patients with NDDs from Children’s Hospitals in Canada and internationally. Patients are enrolled if they have a similarly affected sibling and negative genetic tests, or a de novo balanced chromosomal rearrangement (BCR). We use Next-Generation Sequencing tools to find variation and structural variant breakpoints. Fibroblasts from patients undergo rapid induced pluripotent stem cell (iPSC) re-programming, neural progenitor cell (NPC) differentiation, CRSIPR/Cas9 mutation correction, and finally cell phenotyping. Where feasible, we collect brains from cases with reduced life expectancy. Patient-derived NPCs undergo high-throughput small molecule screening to reverse cell phenotypes associated with disease. Results INVESTICATE has recruited six families, and we identified mutations in genes not previously associated with NDDs. We identified a stop codon altering single base deletion in one family, a 51-basepair promoter deletion in another family, and a gene truncating chromosomal translocation implicating chromatin remodelling, netrins, and maintenance of brain pH in NDDs. Functional assays using iPSC-NPCs of these rare variants support their role in disease. Conclusions INVESTICATE is a rapid bedside-to-bench and back again pipeline capable of finding variants missed using standard methodology, and complements variant detection with a full battery of cell phenotyping assays, brain collection, and high-throughput screening. INVESTICATE is well positioned to attempt to provide cost-effective, personalised care to children with NDDss.

We report pediatric emergency department (PED) asthma visit and inpatient asthma (AS) admission data in our area over a 5-year period. AS visits decreased by 33.9%, AS admissions by 24.6%, both significant compared with the decline in elementary school enrollment. The decrease in asthma visits was due to a decrease in the number of asthmatic patients, not a decline in repeat visits, or use of alternate venues of care. Explanations include a decrease in the burden of disease or an improvement in ambulatory care, but not alternate treatment venues or improvement in acute (PED) care. Readily available, emergency department data are useful in the community surveillance of asthma.