Yair Anikster

Tel Aviv University, Tell Afif, Tel Aviv, Israel

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Publications (113)791.87 Total impact

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    ABSTRACT: Identification of CD59 p.Cys89Tyr mutation in 5 patients from North-African Jewish origin presenting with chronic inflammatory demyelinating polyradiculoneuropathy like disease and chronic hemolysis, led us to reinvestigate an unsolved disease in 2 siblings from the same origin who died 17 years ago. The two patients carried the same CD59 gene mutation previously described by our group. These children had quiet similar disease course but in addition developed devastating recurrent brain infarctions, retinal and optic nerve involvement. Revising the brain autopsy of one of these patients confirmed the finding of multiple brain infarctions of different ages. CD59 protein expression was missing on brain endothelial cells by immunohistochemical staining. This new data expands the clinical spectrum of CD59 mutations and further emphasizes the need for its early detection and treatment. Copyright © 2015 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.
    European journal of paediatric neurology: EJPN: official journal of the European Paediatric Neurology Society 07/2015; DOI:10.1016/j.ejpn.2015.07.001 · 1.93 Impact Factor
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    ABSTRACT: Costeff syndrome or OPA3-related 3-methylglutaconic aciduria is an autosomal recessive neurodegenerative disorder characterized by early onset optic atrophy and choreoathetosis with later onset of ataxia and spasticity. Costeff syndrome is prevalent among Iraqi Jews. We describe a 5 year old girl from Syrian Jewish origin with an atypical presentation of Costeff syndrome. The patient presented with asymmetric optic atrophy, severe dystonia and choreoathetosis and global developmental regression at the age of 7 months; no achievement of independent walking and only minimal speech; and appearance of electrical status epilepticus during slow wave sleep in the second year of life with further deterioration. She harbors the classic mutation (c.143-1G > C) in the OPA3 gene. Costeff syndrome may present in an atypical manner regarding the ethnic origin, clinical manifestations and co-occurrence of epilepsy. Mutations in OPA3 should be evaluated in all cases presenting with the core features of typical Costeff syndrome. Copyright © 2015 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.
    European journal of paediatric neurology: EJPN: official journal of the European Paediatric Neurology Society 07/2015; DOI:10.1016/j.ejpn.2015.06.006 · 1.93 Impact Factor
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    ABSTRACT: Two unrelated patients, presenting with significant global developmental delay, severe progressive microcephaly, seizures, spasticity and thin corpus callosum underwent trio whole exome sequencing. No candidate variant was found in any known genes related to the phenotype. However, crossing the data of the patients illustrated that they both manifested pathogenic variants in the SLC1A4 gene which codes the ASCT1 transporter of serine and other neutral amino acids. The Ashkenazi patient is homozygous for a deleterious missense c.766G>A, p.(E256K) mutation whereas the Ashkenazi-Iraqi patient is compound heterozygous for this mutation and a nonsense c.945delTT, p.(Leu315Hisfs*42) mutation. Structural prediction demonstrates truncation of significant portion of the protein by the nonsense mutation and speculates functional disruption by the missense mutation. Both mutations are extremely rare in general population databases, however the missense mutation was found in heterozygous mode in 1:100 Jewish Ashkenazi controls suggesting a higher carrier rate among Ashkenazi Jews. We conclude that SLC1A4 is the disease causing gene of a novel neurologic disorder manifesting with significant intellectual disability, severe postnatal microcephaly, spasticity and thin corpus callosum. The role of SLC1A4 in the serine transport from astrocytes to neurons suggests a possible pathomechanism for this disease and implies a potential therapeutic approach. This article is protected by copyright. All rights reserved.
    Clinical Genetics 07/2015; DOI:10.1111/cge.12637 · 3.65 Impact Factor
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    ABSTRACT: We describe the molecular basis of a distinctive syndrome characterized by infantile stress-induced episodic weakness, ataxia, and sensorineural hearing loss, with permanent areflexia and optic nerve pallor. Whole exome sequencing identified a deleterious heterozygous c.2452 G>A, p.(E818K) variant in the ATP1A3 gene and structural analysis predicted its protein-destabilizing effect. This variant has not been reported in context with rapid-onset dystonia parkinsonism and alternating hemiplegia of childhood, the 2 main diseases associated with ATP1A3. The clinical presentation in the family described here differs categorically from these diseases in age of onset, clinical course, cerebellar over extrapyramidal movement disorder predominance, and peripheral nervous system involvement. While this paper was in review, a highly resembling phenotype was reported in additional patients carrying the same c.2452 G>A variant. Our findings substantiate this variant as the cause of a unique inherited autosomal dominant neurologic syndrome that constitutes a third allelic disease of the ATP1A3 gene. © The Author(s) 2015.
    Journal of child neurology 04/2015; DOI:10.1177/0883073815579708 · 1.67 Impact Factor
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    ABSTRACT: Costeff syndrome is a rare genetic neuro-ophthalmological syndrome consisting of early-onset bilateral optic atrophy along with a progressive complex motor disorder with elevated levels of urinary 3-methylglutaconic acid and 3-methylglutaric acid. While borderline to mild cognitive deficits have been considered to be common in patients with this syndrome, a comprehensive cognitive assessment has never been performed. The aim of the current study was to explore the cognitive profile associated with Costeff syndrome. Sixteen adult patients diagnosed with Costeff syndrome were administered a neuropsychological test battery that was composed of standardized verbal tests adapted for the blind. General intelligence ranged from average to borderline, with a group mean consistent with intact general cognitive functioning (VIQmean = 85, z = -1) in the low-average range of the general population. The auditory immediate and delayed memory indexes were in the average range and were significantly higher than the general cognitive functioning, whereas the working memory index was significantly lower than the general cognitive functioning. Adult patients with Costeff syndrome have intact global cognition and learning abilities and strong auditory memory performance. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.
    American Journal of Medical Genetics Part B Neuropsychiatric Genetics 02/2015; 168(3). DOI:10.1002/ajmg.b.32296 · 3.27 Impact Factor
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    ABSTRACT: Purpose:Despite the recognized clinical value of exome-based diagnostics, methods for comprehensive genomic interpretation remain immature. Diagnoses are based on known or presumed pathogenic variants in genes already associated with a similar phenotype. Here, we extend this paradigm by evaluating novel bioinformatics approaches to aid identification of new gene-disease associations.Methods:We analyzed 119 trios to identify both diagnostic genotypes in known genes and candidate genotypes in novel genes. We considered qualifying genotypes based on their population frequency and in silico predicted effects we also characterized the patterns of genotypes enriched among this collection of patients.Results:We obtained a genetic diagnosis for 29 (24%) of our patients. We showed that patients carried an excess of damaging de novo mutations in intolerant genes, particularly those shown to be essential in mice (P = 3.4 × 10(-8)). This enrichment is only partially explained by mutations found in known disease-causing genes.Conclusion:This work indicates that the application of appropriate bioinformatics analyses to clinical sequence data can also help implicate novel disease genes and suggest expanded phenotypes for known disease genes. These analyses further suggest that some cases resolved by whole-exome sequencing will have direct therapeutic implications.Genet Med advance online publication 15 January 2015Genetics in Medicine (2015); doi:10.1038/gim.2014.191.
    Genetics in medicine: official journal of the American College of Medical Genetics 01/2015; DOI:10.1038/gim.2014.191 · 6.44 Impact Factor
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    ABSTRACT: Glutaric Aciduria type I (GA-I) is a rare organic acidemia, caused by mutations in the GCDH gene, and characterized by encephalopathic crises with neurological sequelae. We report herein a patient with GA-I who presented with severe acute renal failure requiring dialysis, following an acute diarrheal illness. Histopathological evaluation demonstrated acute tubular necrosis, and molecular diagnosis revealed the patient to be homozygous for a previously unreported mutation, p.E64D. As renal impairment is not part of the clinical spectrum typical to GA-I, possible associations of renal failure and the underlying inborn error of metabolism are discussed, including recent advancements made in the understanding of the renal transport of glutaric acid and its derivatives during metabolic disturbance in GA-I.
    12/2014; 1:170–175. DOI:10.1016/j.ymgmr.2014.03.001
  • Clinical Genetics 10/2014; 87(6). DOI:10.1111/cge.12494 · 3.65 Impact Factor
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    ABSTRACT: Costeff syndrome (CS) is a rare autosomal-recessive neurological disorder, which is known almost exclusively in patients of Iraqi Jewish descent, manifesting in childhood with optic atrophy, ataxia, chorea and spastic paraparesis. Our aim was to study the clinical spectrum of CS and natural history using a cross-sectional study design. Consecutive patients with CS were recruited to the study. Patients were diagnosed based on clinical features, along with elevated urinary levels of methylglutaconic and methylglutaric acid, and by identification of the disease-causing mutation in the OPA3 gene in most. All patients were examined by a neurologist and signs and symptoms were rated. 28 patients with CS (16 males, 21 families, age at last observation 28.6 ± 16.1 years, range 0.5-68 years) were included. First signs of neurological deficit appeared in infancy or early childhood, with delayed motor milestones, choreiform movements, ataxia and visual disturbances. Ataxia and chorea were the dominant motor features in childhood, but varied in severity among patients and did not seem to worsen with age. Pyramidal dysfunction appeared later and progressed with age (r = 0.71, p < 0.001) leading to spastic paraparesis and marked gait impairment. The course of neurological deterioration was slow and the majority of patients could still walk beyond the fifth decade. While visual acuity seemed to deteriorate, it did not correlate with age. CS is a rare neurogenetic disorder that causes serious disability and worsens with age. Spasticity significantly increases over the years and is the most crucial determinant of neurological dysfunction.
    Journal of Neurology 09/2014; 261(12). DOI:10.1007/s00415-014-7481-x · 3.84 Impact Factor
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    ABSTRACT: Objective Deficiency of pyruvate dehydrogenase complex (PDHC) is the most common genetic disorder leading to lactic acidosis. PDHC deficiency is genetically heterogenous and most patients have defects in the X-linked E1-α gene but defects in the other components of the complex encoded by PDHB, PDHX, DLAT, DLD genes or in the regulatory enzyme encoded by PDP1 have also been found. Phenylbutyrate enhances PDHC enzymatic activity in vitro and in vivo by increasing the proportion of unphosphorylated enzyme through inhibition of pyruvate dehydrogenase kinases and thus, has potential for therapy of patients with PDHC deficiency. In the present study, we investigated response to phenylbutyrate of multiple cell lines harboring all known gene defects resulting in PDHC deficiency.Methods Fibroblasts of patients with PDHC deficiency were studied for their enzyme activity at baseline and following phenylbutyrate incubation. Drug responses were correlated with genotypes and protein levels by Western blotting.ResultsLarge deletions affecting PDHA1 that result in lack of detectable protein were unresponsive to phenylbutyrate, whereas increased PDHC activity was detected in most fibroblasts harboring PDHA1 missense mutations. Mutations affecting the R349-α residue were directed to proteasome degradation and were consistently unresponsive to short-time drug incubation but longer incubation resulted in increased levels of enzyme activity and protein that may be due to an additional effect of phenylbutyrate as a molecular chaperone.InterpretationPDHC enzyme activity was enhanced by phenylbutyrate in cells harboring missense mutations in PDHB, PDHX, DLAT, DLD, and PDP1 genes. In the prospect of a clinical trial, the results of this study may allow prediction of in vivo response in patients with PDHC deficiency harboring a wide spectrum of molecular defects.
    07/2014; 1(7). DOI:10.1002/acn3.73
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    ABSTRACT: The development of the mammalian kidney is a highly complex process dependent upon the interplay of various cell types, secreted morphogens, and the extra-cellular matrix (ECM). Although integrins are the most important receptors for ECM proteins and are ubiquitously expressed during kidney development, mice lacking expression of integrin α3 (Itga3) do not demonstrate a reduced number of nephrons, but mostly a disorganized GBM (glomerular basement membrane) leading to proteinuria. Thus, ITGA3 is considered mostly a passive GBM stabilizer and not an active player in nephrogenesis. Recently, mutations in the human ITGA3 were shown to cause congenital nephrotic syndrome, epidermolysis bullosa and interstitial lung disease, otherwise termed NEP syndrome (Nephrotic syndrome, Epidermolysis bullosa and Pulmonary disease). Herein, we performed histological and molecular analysis on the kidneys of a single patient from the initial cohort harboring an ITGA3 mutation, to illuminate the role of ITGA3 in human renal development. We show the patient to harbor a unique phenotype at birth, including severe unilateral renal hypodysplasia. Interrogation of global gene expression in the hypodysplastic kidney versus three controls (fetal, child and adult kidneys) revealed perturbed expression in several renal developmental pathways implicated in hypodysplasia, including the Wnt, BMP (bone morphogenetic protein) and TGF (transforming growth factor) pathways. Moreover, the affected kidney showed upregulation of early embryonic genes (e.g. OCT4 and PAX8) concomitant with downregulated kidney differentiation markers, implying a defect in proper renal differentiation. In conclusion, we show for the first time that ITGA3 is not merely a passive anchor for renal ECM proteins, as predicted by mouse models. Instead, our results may suggest it plays a central role in the interplay of cells, morphogens and ECM, required for proper nephrogenesis, thus adding ITGA3 to the list of CAKUT (congenital anomalies of the kidney and urinary tract)-causing genes.
    PLoS ONE 03/2014; 9(3):e90879. DOI:10.1371/journal.pone.0090879 · 3.23 Impact Factor
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    ABSTRACT: Glycogen storage disease type III (GSD III) was found in the past with an unusual frequency among North African Jews in Israel. The aim of this study was to review the long-term clinical course of GSD III's patients in Israel. Relevant pediatric and adult clinical units of all Israeli hospitals were approached to report on their GSD III patients. 21 (14 M/7F) live patients were located. The average age of the patients was nearly twenty years. Eleven patients were older than 18 years of age. 76% of the patients were of Jewish North African origin, 14% of Jewish European origin, and 10% were Arab Muslims. The symptoms at presentation were fasting, hypoglycemia, hepatomegaly slight hypotonia in infancy and delayed growth. Although in most of the patients their signs and symptoms ameliorated after childhood, significant complications were observed in some 20% of the patients. Consequently, a life long follow up of GSD-III patients is required.
    Pediatric endocrinology reviews: PER 03/2014; 11(3):318-23.
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    ABSTRACT: BACKGROUND: Polyarteritis nodosa is a systemic necrotizing vasculitis with a pathogenesis that is poorly understood. We identified six families with multiple cases of systemic and cutaneous polyarteritis nodosa, consistent with autosomal recessive inheritance. In most cases, onset of the disease occurred during childhood. METHODS: We carried out exome sequencing in persons from multiply affected families of Georgian Jewish or German ancestry. We performed targeted sequencing in additional family members and in unrelated affected persons, 3 of Georgian Jewish ancestry and 14 of Turkish ancestry. Mutations were assessed by testing their effect on enzymatic activity in serum specimens from patients, analysis of protein structure, expression in mammalian cells, and biophysical analysis of purified protein. RESULTS: In all the families, vasculitis was caused by recessive mutations in CECR1, the gene encoding adenosine deaminase 2 (ADA2). All the Georgian Jewish patients were homozygous for a mutation encoding a Gly47Arg substitution, the German patients were compound heterozygous for Arg169Gln and Pro251Leu mutations, and one Turkish patient was compound heterozygous for Gly47Val and Trp264Ser mutations. In the endogamous Georgian Jewish population, the Gly47Arg carrier frequency was 0.102, which is consistent with the high prevalence of disease. The other mutations either were found in only one family member or patient or were extremely rare. ADA2 activity was significantly reduced in serum specimens from patients. Expression in human embryonic kidney 293T cells revealed low amounts of mutant secreted protein. CONCLUSIONS: Recessive loss-of-function mutations of ADA2, a growth factor that is the major extracellular adenosine deaminase, can cause polyarteritis nodosa vasculopathy with highly varied clinical expression.
    New England Journal of Medicine 02/2014; 370(10). DOI:10.1056/NEJMoa1307362 · 54.42 Impact Factor
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    ABSTRACT: Familial glucocorticoid deficiency (FGD), a rare autosomal recessive disorder of insensitivity to adrenocorticotropic hormone (ACTH), is characterized by isolated glucocorticoid deficiency and preserved mineralocorticoid production. The clinical features include generalized hyperpigmentation, hypoglycemia, failure to thrive, and recurrent infections. Here we describe the case of an infant who exhibited generalized hyperpigmentation and hypoglycemia. A high morning blood ACTH level and low blood cortisol level confirmed the diagnosis of FGD. The patient was found to be homozygous for a novel mutation in the melanocortin-2 receptor gene (635insC, I154H). Early initiation of corticosteroid treatment led to normalization of morning blood ACTH levels and the patient thrived, with subsequent fading of the hyperpigmentation.
    Pediatric Dermatology 11/2013; 31(1). DOI:10.1111/pde.12247 · 1.52 Impact Factor
  • Pediatric Rheumatology 11/2013; 11(Suppl 1):A264-A264. DOI:10.1186/1546-0096-11-S1-A264 · 1.62 Impact Factor
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    Dataset: mmc1
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    ABSTRACT: We analyzed four families that presented with a similar condition characterized by congenital microcephaly, intellectual disability, progressive cerebral atrophy, and intractable seizures. We show that recessive mutations in the ASNS gene are responsible for this syndrome. Two of the identified missense mutations dramatically reduce ASNS protein abundance, suggesting that the mutations cause loss of function. Hypomorphic Asns mutant mice have structural brain abnormalities, including enlarged ventricles and reduced cortical thickness, and show deficits in learning and memory mimicking aspects of the patient phenotype. ASNS encodes asparagine synthetase, which catalyzes the synthesis of asparagine from glutamine and aspartate. The neurological impairment resulting from ASNS deficiency may be explained by asparagine depletion in the brain or by accumulation of aspartate/glutamate leading to enhanced excitability and neuronal damage. Our study thus indicates that asparagine synthesis is essential for the development and function of the brain but not for that of other organs.
    Neuron 10/2013; 80(2):429-41. DOI:10.1016/j.neuron.2013.08.013 · 15.98 Impact Factor
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    ABSTRACT: Phenylalanine (Phe) deficiency and its clinical manifestations have been previously described mostly as sporadic case reports dating back to the 1960's and 1970's. In these reports, low plasma Phe levels were associated with listlessness, eczematous eruptions and failure to gain weight, most often in infants in their first year of life. Herein we describe a 9month old female patient with known phenylketonuria, who presented with an unusual constellation of symptoms, including severe erythema and desquamation, alopecia, keratomalacia, corneal perforation, failure to thrive and prolonged diarrhea. The diagnostic possibilities of acrodermatitis enteropathica and vitamin deficiencies were ruled out, and further investigation into her medical history led to the conclusion that during the weeks preceding the hospitalization, the patient's diet consisted of the phenylalanine-free medical formula alone, without the addition of a standard infant formula or food as recommended. Subsequently, dietary control of the blood phenylalanine levels brought swift and marked resolution of the dermatological lesions, with renewal of hair growth. Following this experience, and due to the relative paucity of data regarding the clinical manifestations of low serum phenylalanine levels in humans and their putative pathogenetic mechanisms, we sought to further investigate the effects of a phenylalanine-free diet in a mouse study. For this purpose, twenty mice were randomly allocated to receive either a phenylalanine-deficient diet (n=10) or a normal diet (n=10). Weight was measured weekly, and laboratory tests were obtained including complete blood count, electrolyte studies, and phenylalanine and tyrosine levels. Finally, necropsies and histopathological examinations of different tissues were performed in selected mice, either early after diet initiation, late after diet initiation or following re-introduction of normal diets. The study was then repeated in additional two groups of mice, for a period of up to thirteen weeks, with a total of 63 mice. Gross lesions noted on necropsy in the Phe-deficient mice included scruffy coat, tendency toward weight loss, a reduction in thymic mass, and most notably severe gastric dilation, all of which were not seen in the controls. Histologic findings included thymic depletion, hepatocellular vacuolation, and exocrine pancreatic atrophy. No histopathological lesions were evident in the brain, nor were significant lesions in the eyes. Diagnosis of the iatrogenic condition of phenylalanine deficiency, which manifests in gastrointestinal, dermatological and ocular findings, requires a high index of suspicion. Mice fed a phenylalanine-deficient diet display to some extent similar organ involvement, although no eye abnormalities were evident.
    Molecular Genetics and Metabolism 10/2013; DOI:10.1016/j.ymgme.2013.10.006 · 2.83 Impact Factor
  • Neuromuscular Disorders 10/2013; 23(9-10):772-773. DOI:10.1016/j.nmd.2013.06.480 · 3.13 Impact Factor

Publication Stats

2k Citations
791.87 Total Impact Points

Institutions

  • 2005–2015
    • Tel Aviv University
      • Sackler Faculty of Medicine
      Tell Afif, Tel Aviv, Israel
  • 2005–2014
    • Sheba Medical Center
      Gan, Tel Aviv, Israel
  • 1998–2006
    • National Human Genome Research Institute
      Maryland, United States
  • 2000–2003
    • National Institutes of Health
      • Section on Human Genetics
      베서스다, Maryland, United States
  • 1999–2002
    • National Institute of Child Health and Human Development
      Maryland, United States
    • University of California, San Diego
      • Department of Pediatrics
      San Diego, California, United States
  • 1997–2002
    • Shaare Zedek Medical Center
      • Department of Pediatrics
      Yerushalayim, Jerusalem, Israel
  • 2001
    • Northern Inyo Hospital
      BIH, California, United States