Y Sever

Ben-Gurion University of the Negev, Beersheba, Southern District, Israel

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Publications (9)2.37 Total impact

  • European Psychiatry - EUR PSYCHIAT. 01/2007; 22.
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    ABSTRACT: Low serotonin activity has been associated in both animal and human studies with measures of impulsivity, aggression, and disinhibited behaviors. Recently, a common 44-bp deletion in the promoter region of the serotonin transporter (5-HTTLPR) that results in reduced transcription and lower transporter protein levels was described. Toward unraveling a possible role of the 5-HTTLPR polymorphism in childhood disruptive behaviors, we examined this gene in attention deficit hyperactivity disorder (ADHD), a heterogeneous childhood disorder in which three phenotypes are recognized by DSM IV criteria: inattentive (type I), hyperactive-impulsive (type II), and combined type (type III). By using the haplotype relative risk design, a group of 98 triads (both parents and proband child) were tested for a possible association between 5-HTTLPR and ADHD. A significant decrease in the short/short 5-HTTLPR genotype was observed in the ADHD type III combined group (10.29% vs. 30.88%) compared with the HRR-derived control group (likelihood ratio = 9.62, P = 0.008, n = 68 triads). Similar results were observed when allele frequencies were compared (likelihood ratio = 3.81, P = 0.05, n = 136 alleles). These first findings should be interpreted cautiously until replicated in independently recruited clinical samples.
    American Journal of Medical Genetics 02/2001; 105(1):91-5.
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    ABSTRACT: Attention deficit hyperactivity disorder (ADHD) is a developmental syndrome expressed along three domains: inattention, hyperactive-impulsive, and combined type. Both environmental and genetic factors contribute to the etiology of this complex disease. We previously reported an association in 48 ADHD triads (both parents and proband) between the catechol-O-methyl- transferase (COMT) polymorphism (especially the high enzyme activity val allele) and the Diagnostic and Statistical Manual of Mental Disorders (DSM IV) combined category (excluding inattention) of ADHD (however, see erratum, Am. J. Med. Genet. [Neuropsychiatr. Genet.] 96:893). In the current report, we attempted to replicate this finding in an independently recruited group of 70 nuclear families using the haplotype relative risk design. In the current investigation, no evidence for association of the COMT polymorphism and ADHD (or any of the DSM IV subtypes) was observed in either the current cohort or the expanded cohort of 118 Israeli triads. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:858-860, 2000.
    American Journal of Medical Genetics 01/2001; 96(6):858-60.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Attention deficit hyperactivity disorder (ADHD) is a developmental syndrome expressed along three domains: inattention, hyperactive-impulsive, and combined type. Both environmental and genetic factors contribute to the etiology of this complex disease. We previously reported an association in 48 ADHD triads (both parents and proband) between the catechol-O-methyl- transferase (COMT) polymorphism (especially the high enzyme activity val allele) and the Diagnostic and Statistical Manual of Mental Disorders (DSM IV) combined category (excluding inattention) of ADHD (however, see erratum, Am. J. Med. Genet. [Neuropsychiatr. Genet.] 96:893). In the current report, we attempted to replicate this finding in an independently recruited group of 70 nuclear families using the haplotype relative risk design. In the current investigation, no evidence for association of the COMT polymorphism and ADHD (or any of the DSM IV subtypes) was observed in either the current cohort or the expanded cohort of 118 Israeli triads. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:858–860, 2000. © 2000 Wiley-Liss, Inc.
    American Journal of Medical Genetics 12/2000; 96(6):858 - 860.
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    ABSTRACT: The DRD4 exon III repeat polymorphism has been associated in adults with Novelty Seeking personality traits and in children with attention deficit hyperactivity disorder (ADHD) in some but not all studies. In a previous report we failed to observe preferential transmission of the long DRD4 repeat in ADHD compared to the haplotype relative risk (HRR) derived control group in a group of 49 triads (both parents and ADHD child) recruited in the Jerusalem area. In the current study we independently recruited an additional group of 49 triads from a different geographical location (Petak Tikvah) in Israel but having a similar ethnic background. In contrast to previous findings from a number of groups, in the current study an excess of the long DRD4 alleles was observed in the HRR control group compared to the ADHD subjects (Likelihood ratio = 5.50, P = 0. 02). In the expanded Israeli group of 98 triads so-far examined for the DRD4 repeat polymorphism there is an excess of the long alleles in the HRR control group (Likelihood ratio = 3.81, P = 0.05). These results attest to the complexity of ADHD inheritance and the likelihood that genetic heterogeneity characterizes this disorder especially across ethnic and cultural boundaries.
    American Journal of Medical Genetics 07/2000; 96(3):278-81.
  • Am J of Med Genet. 01/2000; 96(6):858-860.
  • [Show abstract] [Hide abstract]
    ABSTRACT: The DRD4 exon III repeat polymorphism has been associated in adults with Novelty Seeking personality traits and in children with attention deficit hyperactivity disorder (ADHD) in some but not all studies. In a previous report we failed to observe preferential transmission of the long DRD4 repeat in ADHD compared to the haplotype relative risk (HRR) derived control group in a group of 49 triads (both parents and ADHD child) recruited in the Jerusalem area. In the current study we independently recruited an additional group of 49 triads from a different geographical location (Petak Tikvah) in Israel but having a similar ethnic background. In contrast to previous findings from a number of groups, in the current study an excess of the long DRD4 alleles was observed in the HRR control group compared to the ADHD subjects (Likelihood ratio = 5.50, P = 0. 02). In the expanded Israeli group of 98 triads so-far examined for the DRD4 repeat polymorphism there is an excess of the long alleles in the HRR control group (Likelihood ratio = 3.81, P = 0.05). These results attest to the complexity of ADHD inheritance and the likelihood that genetic heterogeneity characterizes this disorder especially across ethnic and cultural boundaries. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:278- 281, 2000. Copyright 2000 Wiley-Liss, Inc.
    Am J Med Genet. 01/2000; 96(3):278-81.
  • I Manor, Y Sever, A Weizman
    Harefuah 06/1999; 136(10):812-5.
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    ABSTRACT: Iron plays a role in the regulation of dopaminergic activity. In the present study, nonanemic children with attention deficit hyperactivity disorder (ADHD) were evaluated with regard to heme and nonheme iron metabolism and the effect of short-term iron administration on behavior. The study group consisted of 14 boys aged 7–11 years. All first underwent testing to rule out other psychiatric and medical problems. The severity of the ADHD symptoms was determined by parent and teacher scores on the Connors Rating Scale. Thereafter, each patient received an iron preparation (Ferrocal), 5 mg/kg/day for 30 days. Blood samples were taken before and after drug administration. Results showed a significant increase in serum ferritin levels (from 25.9 ± 9.2 to 44.6 ±18 ng/ml) and a significant decrease on the parents’ Connors Rating Scale scores (from 17.6 ± 4.5 to 12.7 ± 5.4). There were no changes in other blood parameters or in the teachers’ scores on the rating scale. The effect of iron supplementation on the behavioral and cognitive symptoms in noniron-deficient ADHD children merits further investigation using a placebo-controlled study.Copyright © 1997 S. Karger AG, Basel
    Neuropsychobiology 01/1997; 35(4):178-180. · 2.37 Impact Factor

Publication Stats

256 Citations
2.37 Total Impact Points

Institutions

  • 2000
    • Ben-Gurion University of the Negev
      • Faculty of Health Sciences
      Beersheba, Southern District, Israel
  • 1997
    • Tel Aviv University
      Tell Afif, Tel Aviv, Israel