Publications by authors named "Alexa Derksen"

GNE myopathy, also known as hereditary inclusion body myopathy (HIBM), is a rare genetic muscle disorder marked by a gradual onset of muscle weakness in young adults. GNE myopathy (GNEM) is caused by bi-allelic variants in the UDP--acetylglucosamine 2-epimerase (UDP-GlcNAc 2-epimerase)/-acetylmannosamine kinase (ManNAc kinase) gene (), clinically resulting in the loss of ambulation within 10-20 years from the onset of the initial symptoms. The disease's mechanism is poorly understood and non-invasive biomarkers are lacking, hindering effective therapy development.

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Background: Cockayne syndrome (CS) is a DNA repair disorder primarily associated with pathogenic variants in ERCC6 and ERCC8. As in other Mendelian disorders, there are a number of genetically unsolved CS cases.

Methods: We ascertained five individuals with monoallelic pathogenic variants in MORC2, previously associated with three dominantly inherited phenotypes: an axonal form of Charcot-Marie-Tooth disease type 2Z; a syndrome of developmental delay, impaired growth, dysmorphic facies, and axonal neuropathy; and a rare form of spinal muscular atrophy.

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Cockayne syndrome is a rare inherited DNA repair multisystemic disorder. Here, we aim to raise awareness of the phenotypic resemblances between Cockayne syndrome and the neurodevelopmental disorder caused by pathogenic variants in MORC2, a gene also involved in DNA repair. Using exome sequencing, we identified a de novo pathogenic variant in MORC2 in our patient.

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The endocannabinoid system is a highly conserved and ubiquitous signalling pathway with broad-ranging effects. Despite critical pathway functions, gene variants have not previously been conclusively linked to human disease. We identified nine children from eight families with heterozygous, de novo truncating variants in the last exon of DAGLA with a neuro-ocular phenotype characterized by developmental delay, ataxia and complex oculomotor abnormality.

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Background: Excessive opioid prescribing after surgery has contributed to the current opioid crisis; however, the value of prescribing opioids at surgical discharge remains uncertain. We aimed to estimate the extent to which opioid prescribing after discharge affects self-reported pain intensity and adverse events in comparison with an opioid-free analgesic regimen.

Methods: In this systematic review and meta-analysis, we searched MEDLINE, Embase, the Cochrane Library, Scopus, AMED, Biosis, and CINAHL from Jan 1, 1990, until July 8, 2021.

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Article Synopsis
  • Autosomal Dominant Hypercholesterolemia (ADH) is a genetic condition linked to mutations in specific genes, and the study focused on identifying new candidate genes in a French family with varying ADH risk.
  • Researchers used advanced genetic techniques to find multiple mutations in known and unknown genes, discovering a set of variants connected with the ADH trait among patients.
  • Despite identifying several genetic variants, the findings indicate that no single variant causes elevated LDL cholesterol; rather, a combination of these variants seems necessary to express the ADH phenotype.
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Negative regulator of reactive oxygen species (NRROS) is a leucine-rich repeat protein expressed by microglia and perivascular macrophages. To date, 9 individuals have been reported with biallelic NRROS variants. Here, we report one individual with a severe neurodegenerative phenotype in which exome sequencing identified 2 novel variants in NRROS, a missense variant (c.

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Leukodystrophies, genetic neurodevelopmental and/or neurodegenerative disorders of cerebral white matter, result from impaired myelin homeostasis and metabolism. Numerous genes have been implicated in these heterogeneous disorders; however, many individuals remain without a molecular diagnosis. Using whole-exome sequencing, biallelic variants in were uncovered in two unrelated individuals, one with a leukodystrophy and the other who died .

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ABHD16A (abhydrolase domain-containing protein 16A, phospholipase) encodes the major phosphatidylserine (PS) lipase in the brain. PS lipase synthesizes lysophosphatidylserine, an important signaling lipid that functions in the mammalian central nervous system. ABHD16A has not yet been associated with a human disease.

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Purpose: Recent reports of individuals with cytoplasmic transfer RNA (tRNA) synthetase-related disorders have identified cases with phenotypic variability from the index presentations. We sought to assess phenotypic variability in individuals with AARS1-related disease.

Methods: A cross-sectional survey was performed on individuals with biallelic variants in AARS1.

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Mutations in have been shown to cause spinal muscular atrophy lower extremity predominant type 1 (SMALED1), an autosomal dominant genetic neuromuscular disorder characterized by degeneration of spinal cord motor neurons resulting in muscle weakness. Here, we describe monozygotic twins, one with a more severe upper motor neuron phenotype as a result of a suspected perinatal hypoxic-ischemic event and the other presenting a typical lower motor neuron phenotype. Using exome sequencing, we identified the novel variant c.

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Hypomyelinating leukodystrophies are a group of genetic disorders characterized by insufficient myelin deposition during development. A subset of hypomyelinating leukodystrophies, named RNA polymerase III (Pol III or POLR3)-related leukodystrophy or 4H (Hypomyelination, Hypodontia and Hypogonadotropic Hypogonadism) leukodystrophy, was found to be caused by biallelic variants in genes encoding subunits of the enzyme Pol III, including POLR3A, POLR3B, POLR3K, and POLR1C. Pol III is one of the three nuclear RNA polymerases that synthesizes small non-coding RNAs, such as tRNAs, 5S RNA, and others, that are involved in the regulation of essential cellular processes, including transcription, translation and RNA maturation.

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The primary motor symptoms of Parkinson's disease (PD) result from the degeneration of dopamine-producing neurons of the substantia nigra pars compacta (SNc), and often, the loss is asymmetrical, resulting in unilateral tremor presentation. Notably, age is the primary risk factor for PD, and it is likely that the disease ultimately stems from the impact of environmental factors, which interact with the aging process. Recent research has focused on the role of microglia and pro-oxidative responses in dopaminergic neuronal death.

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Leucine-rich repeat kinase 2 (LRRK2) is a common gene implicated in Parkinson's disease and many inflammatory processes. Thus, we assessed the role of LRRK2 in the context of endotoxin (lipopolysaccharide, LPS)-induced inflammation of the substantia nigra together with the environmental toxicant, paraquat, that has been implicated in PD. Here we found that LRRK2 ablation prevented the loss of dopaminergic neurons and behavioral deficits (motor) induced by LPS priming followed by paraquat exposure.

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Introduction: Excessive prescribing after surgery has contributed to a public health crisis of opioid addiction and overdose in North America. However, the value of prescribing opioids to manage postoperative pain after surgical discharge remains unclear. We propose a systematic review and meta-analysis to assess the extent to which opioid analgesia impact postoperative pain intensity and adverse events in comparison to opioid-free analgesia in patients discharged after surgery.

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Article Synopsis
  • Parkinson's disease leads to a loss of dopamine-producing neurons, and current treatments mainly alleviate motor symptoms without significant neurorecovery.
  • In a study, the mGluR5-negative allosteric modulator CTEP was tested in a mouse model for its effects on motor deficits and neural recovery.
  • Results showed that CTEP improved motor function and promoted neural recovery, potentially by activating the mTOR pathway, suggesting that targeting this pathway could enhance neuroplasticity in Parkinson's disease patients.
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