Publications by authors named "Nassogne M"

Article Synopsis
  • * The study identifies RNU4-2, a non-coding RNA gene, as a significant contributor to syndromic NDD, revealing a specific 18-base pair region with low variation that includes variants found in 115 individuals with NDD.
  • * RNU4-2 is highly expressed in the developing brain, and its variants disrupt splicing processes, indicating that non-coding genes play a crucial role in rare disorders, potentially aiding in the diagnosis of thousands with NDD worldwide.
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Empagliflozin has been successfully repurposed for treating neutropenia and neutrophil dysfunction in patients with glycogen storage disease type 1b (GSD 1b), however, data in infants are missing. We report on efficacy and safety of empagliflozin in infants with GSD 1b. This is an international retrospective case series on 21 GSD 1b infants treated with empagliflozin (total treatment time 20.

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Around 60% of individuals with neurodevelopmental disorders (NDD) remain undiagnosed after comprehensive genetic testing, primarily of protein-coding genes. Increasingly, large genome-sequenced cohorts are improving our ability to discover new diagnoses in the non-coding genome. Here, we identify the non-coding RNA as a novel syndromic NDD gene.

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Leigh syndrome spectrum (LSS) is a primary mitochondrial disorder defined neuropathologically by a subacute necrotizing encephalomyelopathy and characterized by bilateral basal ganglia and/or brainstem lesions. LSS is associated with variants in several mitochondrial DNA genes and more than 100 nuclear genes, most often related to mitochondrial complex I (CI) dysfunction. Rarely, LSS has been reported in association with primary Leber hereditary optic neuropathy (LHON) variants of the mitochondrial DNA, coding for CI subunits (m.

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  • Fatty acid oxidation (FAO) disorders are genetic conditions that disrupt the body's ability to process fatty acids, leading to serious health crises during fasting or illness.
  • A study analyzed 54 patients, revealing that a majority (64.8%) were diagnosed through newborn screening, with medium-chain acyl-CoA dehydrogenase deficiency being the most common.
  • The research highlights the significant benefits of newborn screening in Southern Belgium, which has improved neurological outcomes by reducing metabolic crises and preventing mortality in affected patients.
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  • - Capillary malformations (CMs) are the most common vascular anomalies in newborns, often linked to mutations in genes like GNAQ and GNA11, but can also involve different mutations in cases with additional complications.
  • - This study explored two young patients with CM-like features who presented with severe epilepsy and brain anomalies, revealing somatic mutations in the AKT3 gene instead of the more common mutations typically associated with CMs.
  • - The findings highlight the necessity for comprehensive genetic analysis and awareness of atypical symptoms, emphasizing how genotype-phenotype correlations can aid clinicians in making better-informed decisions for patient management.
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Alternating hemiplegia of childhood (AHC) is a rare neurodevelopment disorder that is typically characterized by debilitating episodic attacks of hemiplegia, seizures, and intellectual disability. Over 85% of individuals with AHC have a de novo missense variant in ATP1A3 encoding the catalytic α3 subunit of neuronal NaK ATPases. The remainder of the patients are genetically unexplained.

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Article Synopsis
  • * These metabolic defects can result in various neurological issues, including psychomotor retardation, epilepsy, and sensory problems, which are often nonspecific and may go unnoticed.
  • * Early diagnosis through genetic testing and biochemical screening can improve outcomes for affected children, but many cases remain under-diagnosed, necessitating increased awareness and testing among clinicians.
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  • - Spinocerebellar ataxia 34 (SCA34) is a hereditary disease linked to mutations in the ELOVL4 gene, leading to cerebellar degeneration and motor coordination issues, also involving tissue-specific disorders like skin and retinal conditions.
  • - The case study highlights a young girl with early-onset severe cerebellar degeneration and retinal dysfunction connected to a novel mutation in the ELOVL4 gene, indicated by MRI and electroretinography findings.
  • - Research aims to explore how the newly identified ELOVL4 variant affects the enzyme's ability to synthesize important fatty acids, potentially explaining the link between the mutation and the patient's neurological and visual impairments.
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Purpose: The study aimed to clinically and molecularly characterize the neurodevelopmental disorder associated with heterozygous de novo variants in CNOT9.

Methods: Individuals were clinically examined. Variants were identified using exome or genome sequencing.

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Children undergoing general anesthesia and surgery in the early years of life are exposed to the possible neurotoxicity of anesthetic agents. Prospective studies have shown deficits in behavior, executive function, social communication, and motor function in children undergoing anesthesia and surgery. Different biomarkers of neuronal injury have been evaluated neuronal injury in the pediatric population, among which neurofilaments represent a significant advantage as they are proteins exclusively expressed in neuronal tissue.

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Poretti-Boltshauser syndrome (PTBHS) is an autosomal recessive disorder characterized by cerebellar dysplasia with cysts and an abnormal shape of the fourth ventricle on neuroimaging, due to pathogenic variants in the LAMA1 gene. The clinical spectrum mainly consists of neurological and ophthalmological manifestations, including non-progressive cerebellar ataxia, oculomotor apraxia, language impairment, intellectual disability, high myopia, abnormal eye movements and retinal dystrophy. We report a patient presenting with ventriculomegaly on antenatal neuroimaging and a neonatal diagnosis of Type III esophageal atresia.

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We report the case of a teenager with a neurofibromatosis Type 2 (NF2) presenting a locked-in syndrome due to a brainstem ischemic syndrome. The presence of sudden or rapidly worsening onset of neurological deficits in NF2 patients, should evoke this underknown entity and not only tumors as predisposed by NF2.

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Article Synopsis
  • MTHFR deficiency is a serious genetic disorder affecting the body’s ability to process homocysteine, leading to severe neurological issues in infants and a lack of long-term outcome data for these patients.
  • This study analyzed clinical data from 72 MTHFR-deficient patients, focusing on those diagnosed before three months of age, to identify factors that predict severe neurodevelopmental problems.
  • Results showed that a significant percentage of early-onset patients had neurological symptoms, and those diagnosed before symptoms exhibited much better long-term outcomes, suggesting the importance of early newborn screening and treatment.
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Free oligosaccharides (fOSs) are soluble oligosaccharide species generated during N-glycosylation of proteins. Although little is known about fOS metabolism, the recent identification of NGLY1 deficiency, a congenital disorder of deglycosylation (CDDG) caused by loss of function of an enzyme involved in fOS metabolism, has elicited increased interest in fOS processing. The catabolism of fOSs has been linked to the activity of a specific cytosolic mannosidase, MAN2C1, which cleaves α1,2-, α1,3-, and α1,6-mannose residues.

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Purines are essential molecules that are components of vital biomolecules, such as nucleic acids, coenzymes, signaling molecules, as well as energy transfer molecules. The de novo biosynthesis pathway starts from phosphoribosylpyrophosphate (PRPP) and eventually leads to the synthesis of inosine monophosphate (IMP) by means of 10 sequential steps catalyzed by six different enzymes, three of which are bi-or tri-functional in nature. IMP is then converted into guanosine monophosphate (GMP) or adenosine monophosphate (AMP), which are further phosphorylated into nucleoside di- or tri-phosphates, such as GDP, GTP, ADP and ATP.

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Article Synopsis
  • Liver disease in children and adults is often of unknown cause, potentially linked to undiagnosed inherited metabolic disorders like fructose-1,6-bisphosphatase deficiency, which has underreported liver symptoms.
  • A study of 18 patients with this deficiency revealed liver abnormalities during both follow-up and acute crises, including hepatomegaly and elevated transaminases.
  • The fatty liver disease associated with this condition may be related to endoplasmic reticulum stress and increased fat production, suggesting the need for ongoing liver monitoring in these patients throughout their lives.
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We report detailed functional analyses and genotype-phenotype correlations in 392 individuals carrying disease-causing variants in SCN8A, encoding the voltage-gated Na+ channel Nav1.6, with the aim of describing clinical phenotypes related to functional effects. Six different clinical subgroups were identified: Group 1, benign familial infantile epilepsy (n = 15, normal cognition, treatable seizures); Group 2, intermediate epilepsy (n = 33, mild intellectual disability, partially pharmaco-responsive); Group 3, developmental and epileptic encephalopathy (n = 177, severe intellectual disability, majority pharmaco-resistant); Group 4, generalized epilepsy (n = 20, mild to moderate intellectual disability, frequently with absence seizures); Group 5, unclassifiable epilepsy (n = 127); and Group 6, neurodevelopmental disorder without epilepsy (n = 20, mild to moderate intellectual disability).

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Background: Primary microcephaly (PM) is defined as a significant reduction in occipitofrontal circumference (OFC) of prenatal onset. Clinical and genetic heterogeneity of PM represents a diagnostic challenge.

Methods: We performed detailed phenotypic and genomic analyses in a large cohort (n = 169) of patients referred for PM and could establish a molecular diagnosis in 38 patients.

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Glycosylation is a fundamental post-translational modification of proteins that boosts their structural diversity providing subtle and specialized biological properties and functions. All those genetic diseases due to a defective glycan biosynthesis and attachment to the nascent glycoproteins fall within the wide area of congenital disorders of glycosylation (CDG), mostly causing multisystem involvement. In the present paper, we detailed the unique serum N-glycosylation of a CDG-candidate patient with an unexplained neurological phenotype and liver adenomatosis harboring a recurrent pathogenic variant.

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