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result(s) for
"Spiegel, Ronen"
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Combined loss of LAP1B and LAP1C results in an early onset multisystemic nuclear envelopathy
2019
Nuclear envelopathies comprise a heterogeneous group of diseases caused by mutations in genes encoding nuclear envelope proteins. Mutations affecting lamina-associated polypeptide 1 (LAP1) result in two discrete phenotypes of muscular dystrophy and progressive dystonia with cerebellar atrophy. We report 7 patients presenting at birth with severe progressive neurological impairment, bilateral cataract, growth retardation and early lethality. All the patients are homozygous for a nonsense mutation in the
TOR1AIP1
gene resulting in the loss of both protein isoforms LAP1B and LAP1C. Patient-derived fibroblasts exhibit changes in nuclear envelope morphology and large nuclear-spanning channels containing trapped cytoplasmic organelles. Decreased and inefficient cellular motility is also observed in these fibroblasts. Our study describes the complete absence of both major human LAP1 isoforms, underscoring their crucial role in early development and organogenesis. LAP1-associated defects may thus comprise a broad clinical spectrum depending on the availability of both isoforms in the nuclear envelope throughout life.
Nuclear envelopathies are a group of diseases caused by genetic mutations in essential nuclear envelope genes. Here, the authors report a nuclear envelopathy with a homozygous nonsense variant in
TOR1AIP1
which leads to changes in the nuclear morphology including large nuclear-spanning channels in patients’ fibroblasts.
Journal Article
Campylobacter gastroenteritis in children in north-eastern Israel comparison with other common pathogens
by
Sakran, Waheeb
,
Spiegel, Ronen
,
Batheesh, Hamed
in
631/326/421
,
692/699/255/1318
,
Anti-Bacterial Agents - therapeutic use
2020
Gastroenteritis is common among children.
Campylobacter jejuni
is one of the main causative bacterial pathogens, together with
Shigella
,
Salmonella
and invasive
Escherichia coli
. Campylobacteriosis is a zoonotic, usually self-limited disease that does not always require antibiotic treatment. In cases of protracted diarrhoea in healthy children or immunocompromised patients, antibiotic treatment is recommended, and the drug of choice is still macrolides, with very low resistance rates in
Campylobacter
species. However, it is crucial to isolate the causative organism, because some cases, such as
Shigella
encephalitis, call for initiation of empiric antibiotic treatment. In this study, we compared the incidence, epidemiology, clinical findings and laboratory results of gastroenteritis with dysentery caused by these organisms in children in our area.
C. jejuni
was found to be the leading pathogen in children hospitalized with bacterial gastroenteritis, followed by
Shigella
and
Salmonella
. Macrolides were the drug of choice for
Campylobacter
, and ceftriaxone and ciprofloxacin were the best empiric treatments for
Shigella
and
Salmonella
, respectively.
Journal Article
Early maturation and hyperexcitability is a shared phenotype of cortical neurons derived from different ASD-associated mutations
2023
Autism Spectrum Disorder (ASD) is characterized mainly by social and sensory-motor abnormal and repetitive behavior patterns. Over hundreds of genes and thousands of genetic variants were reported to be highly penetrant and causative of ASD. Many of these mutations cause comorbidities such as epilepsy and intellectual disabilities (ID). In this study, we measured cortical neurons derived from induced pluripotent stem cells (iPSCs) of patients with four mutations in the genes GRIN2B, SHANK3, UBTF, as well as chromosomal duplication in the 7q11.23 region and compared them to neurons derived from a first-degree relative without the mutation. Using a whole-cell patch-clamp, we observed that the mutant cortical neurons demonstrated hyperexcitability and early maturation compared to control lines. These changes were characterized by increased sodium currents, increased amplitude and rate of excitatory postsynaptic currents (EPSCs), and more evoked action potentials in response to current stimulation in early-stage cell development (3–5 weeks post differentiation). These changes that appeared in all the different mutant lines, together with previously reported data, indicate that an early maturation and hyperexcitability may be a convergent phenotype of ASD cortical neurons.
Journal Article
Desmoglein 1 deficiency results in severe dermatitis, multiple allergies and metabolic wasting
2013
Eli Sprecher, Kathleen Green and colleagues show that biallelic mutations in
DSG1
cause a syndrome featuring severe dermatitis, multiple allergies and metabolic wasting. The mutations abolish expression of desmoglein 1, resulting in loss of cell adhesion accompanied by increased expression of several allergy-related cytokines.
The relative contribution of immunological dysregulation and impaired epithelial barrier function to allergic diseases is still a matter of debate. Here we describe a new syndrome featuring severe dermatitis, multiple allergies and metabolic wasting (SAM syndrome) caused by homozygous mutations in
DSG1
.
DSG1
encodes desmoglein 1, a major constituent of desmosomes, which connect the cell surface to the keratin cytoskeleton and have a crucial role in maintaining epidermal integrity and barrier function. Mutations causing SAM syndrome resulted in lack of membrane expression of DSG1, leading to loss of cell-cell adhesion. In addition, DSG1 deficiency was associated with increased expression of a number of genes encoding allergy-related cytokines. Our deciphering of the pathogenesis of SAM syndrome substantiates the notion that allergy may result from a primary structural epidermal defect.
Journal Article
Lack of mitochondrial complex I assembly factor NDUFAF2 results in a distinctive infantile-onset brainstem neurodegenerative disease with early lethality
2024
Background
Congenital disorders of the mitochondrial respiratory chain are a heterogeneous group of inborn errors of metabolism. Among them, NADH:ubiquinone oxidoreductase (complex I, CI) deficiency is the most common. Biallelic pathogenic variants in
NDUFAF2
, encoding the nuclear assembly CI factor NDUFAF2, were initially reported to cause progressive encephalopathy beginning in infancy. Since the initial report in 2005, less than a dozen patients with
NDUFAF2
-related disease have been reported.
Methods
Clinical, biochemical, and neuroradiological features of four new patients residing in Northern Israel were collected during 2016–2022 at Emek Medical Center. Enzymatic activities of the five respiratory-chain complexes were determined in isolated fibroblast mitochondria by spectrophotometric methods. Western blot analyses were conducted with anti-human NDUFAF2 antibody; antibody against the mitochondrial marker VDAC1 was used as a loading control. Genetic studies were performed by chromosome microarray analysis using Affymetrix CytoScan 750 K arrays.
Results
All four patients presented with infantile-onset growth retardation, ophthalmological impairments with nystagmus, strabismus (starting between 5 and 9 months), and further progressed to life-threatening episodes of apnea usually triggered by trivial febrile illnesses (between 10 and 18 months) with gradual loss of acquired developmental milestones (3 of 4 patients). Serial magnetic-resonance imaging studies in two of the four patients showed a progressive pattern of abnormal T2-weighted hyperintense signals involving primarily the brainstem, the upper cervical cord, and later, the basal ganglia and thalami. Magnetic-resonance spectroscopy in one patient showed an increased lactate peak. Disease progression was marked by ventilatory dependency and early lethality. 3 of the 4 patients tested, harbored a homozygous 142-kb partial interstitial deletion that omits exons 2–4 of
NDUFAF2
. Mitochondrial CI activity was significantly decreased in the only patient tested. Western blot analysis disclosed the absence of NDUFAF2 protein compared to normal controls. In addition, we reviewed all 10 previously reported NDUFAF2-deficient cases to better characterize the disease.
Conclusions
Biallelic loss-of-function mutations in
NDUFAF2
result in a distinctive phenotype in the spectrum of Leigh syndrome with clinical and neuroradiological features that are primarily attributed to progressive brainstem damage.
Journal Article
Inhaled nitric oxide therapy in acute bronchiolitis: A multicenter randomized clinical trial
2020
Currently, there are no approved treatments for infants with acute bronchiolitis, the leading cause for hospitalization of infants worldwide, and thus the recommended approach is supportive. Inhaled Nitric oxide (iNO), possesses anti-viral properties, improves oxygenation, and was shown to be safe in infants with respiratory conditions. Hospitalized infants with acute bronchiolitis were therefore recruited to a prospective double-blinded, multi-center, randomized controlled pilot study. They received intermittent high dose iNO (160 ppm) plus oxygen/air for 30 min or oxygen/air alone (control), five times/day, up to 5 days. Sixty-nine infants were enrolled. No difference was observed in frequencies of subjects with at least one Adverse Event (AE) in iNO (44.1%) vs. control (55.9%); neither was Methemoglobin >7% safety threshold. No drug-related serious AEs (SAEs) were reported. Analysis of Per-Protocol population revealed that length of stay (LOS), time to SpO
2
≥92%, and time to mTal clinical score ≤5 improved by 26.7 ± 12.7 (Welch’s t-test p = 0.04), 20.8 ± 8.9 (p = 0.023), and 14.6 ± 9.1 (p = 0.118) hours, respectively, in the iNO group compared to the control. Overall, high dose iNO (160ppm) was safe, well-tolerated, reduced LOS and showed rapid improvement of oxygen saturation, compared to the standard therapy. Further investigation in larger cohorts is warranted to validate these encouraging efficacy outcomes. (Trial registration: NCT03053388)
Journal Article
Plasma metabolomics reveals a diagnostic metabolic fingerprint for mitochondrial aconitase (ACO2) deficiency
by
Abela, Lucia
,
Papuc, Sorina Mihaela
,
Spiegel, Ronen
in
4-Hydroxynonenal
,
Abnormalities
,
Acetic acid
2017
Mitochondrial respiratory chain dysfunction has been identified in a number of neurodegenerative disorders. Infantile cerebellar-retinal degeneration associated with mutations in the mitochondrial aconitase 2 gene (ACO2) has been recently described as a neurodegenerative disease of autosomal recessive inheritance. To date there is no biomarker for ACO2 deficiency and diagnosis relies on genetic analysis. Here we report global metabolic profiling in eight patients with ACO2 deficiency. Using an LC-MS-based metabolomics platform we have identified several metabolites with affected plasma concentrations including the tricarboxylic acid cycle metabolites cis-aconitate, isocitrate and alpha-ketoglutarate, as well as phosphoenolpyruvate and hydroxybutyrate. Taken together we report a diagnostic metabolic fingerprint for mitochondrial aconitase 2 deficiency.
Journal Article
Clinical profiling and medical management of Israeli individuals with Phelan McDermid syndrome
by
Hady-Cohen, Ronen
,
Weissbach, Tal
,
Frydman, Moshe
in
Adolescent
,
Adult
,
Attention deficit hyperactivity disorder
2025
Background
Phelan–McDermid syndrome (PMS) is a neurodevelopmental disorder, caused by haploinsufficiency of the
SHANK3
gene. In addition to global developmental delay (GDD)/intellectual disability (ID) and autism spectrum disorder (ASD), PMS is characterized by multiple neurologic, behavioral and multisystemic manifestations.
Methods
We aimed to establish a database of individuals with PMS in Israel. All participants underwent a detailed evaluation at a single medical center, and demographic, clinical, and genetic data were collected.
Results
Seventeen unrelated individuals with PMS (mean age 10 ± 8.2 years; range, 2.5–36 years) were enrolled (10 females, 59%), all of Jewish descent. Twelve cases (70%) were caused by deletions in chromosomal region 22q13.3, including mosaicism, ring chromosome and unbalanced translocation. The other 5 (30%) cases were due to single nucleotide variants (SNVs), while the de novo SNV c.3904dup (p.Ala1302GlyfsTer69), recurred in 3 cases. All 17 participants had GDD/ID (which was severe in 10, 59%), and ASD and seizures were present in 12 (70%) and 8 (47%) individuals, respectively. Additional frequent manifestations were sleep difficulties in 13 individuals (76%), bowel movement disorders in 13 (76%), urinary track involvement in 8 (47%) and endocrine disorders in 6 (35%). Abnormal but nonspecific findings on prenatal ultrasonography were noted in 3 participants (18%). The most common perinatal complication was prolonged jaundice in 5 infants (29%). Different medical treatment modalities, including cannabidiol (CBD) full-spectrum oil extracts, were used to ease symptoms, with variable results.
Conclusions
Our experience adds to current knowledge about clinical manifestations and potential symptomatic treatment of PMS in Israel. These findings may promote clinical research and serve as infrastructure for future clinical trials.
Journal Article
A novel de novo heterozygous pathogenic variant in the SDHA gene results in childhood onset bilateral optic atrophy and cognitive impairment
2021
Isolated defects in the mitochondrial respiratory chain complex II (CII; succinate-ubiquinone oxidoreductase) are extremely rare and mainly result from bi-allelic mutations in one of the nuclear encoded subunits: SDHA, SDHB and SDHD, which comprise CII and the assembly CII factor SDHAF1. We report an adolescent female who presented with global developmental delay, intellectual disability and childhood onset progressive bilateral optic atrophy. Whole exome sequencing of the patient and her unaffected parents identified the novel heterozygous de novo variant c.1984C > T [NM_004168.4] in the SDHA gene. Biochemical assessment of CII in the patient’s derived fibroblasts and lymphocytes displayed considerably decreased CII residual activity compared with normal controls, when normalized to the integral mitochondrial enzyme citrate synthase. Protein modeling of the consequent p.Arg662Cys variant [NP-004159.2] suggested that this substitution will compromise the structural integrity of the FAD-binding protein at the C-terminus that will ultimately impair the FAD binding to SDHA, thus decreasing the entire CII activity. Our study emphasizes the role of certain heterozygous SDHA mutations in a distinct clinical phenotype dominated by optic atrophy and neurological impairment. This is the second mutation that has been reported to cause this phenotype. Furthermore, it adds developmental delay and cognitive disability to the expanding spectrum of the disorder. We propose to add SDHA to next generation sequencing gene panels of optic atrophy.
Journal Article