Varda Gross-Tsur

Hebrew University of Jerusalem, Yerushalayim, Jerusalem, Israel

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Publications (111)383.18 Total impact

  • H.J. Hirsch · T Eldar-Geva · F Bennaroch · Y Pollak · V Gross-Tsur
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    ABSTRACT: STUDY QUESTION At what age does the type of hypogonadism, namely hypothalamic or primary gonadal defect, become established in men and women with Prader-Willi syndrome (PWS)? SUMMARY ANSWER The type of hypogonadism becomes established only in late adolescence and early adulthood. WHAT IS KNOWN ALREADY The etiology of hypogonadism in PWS is heterogeneous and the clinical expression is variable. Primary testicular failure is common in PWS men, while combinations of ovarian dysfunction and gonadotrophin deficiency are seen in women. STUDY DESIGN, SIZE, DURATION This is a prospective study of a cohort of 106 PWS patients followed for a mean duration of 4.5 years. Serial blood samples were obtained and assayed for gonadotrophins, inhibin B, anti-Mullerian hormone (AMH), dehydroepiandrosterone sulfate (DHEAS), testosterone (males), and estradiol (females). Results were compared with normal reference values obtained from the literature. For the purpose of this study, we defined the following age groups: infants <1 year; children 1-10 years; adolescents 11-20 years and adults >20 years. PARTICIPANTS/MATERIALS, SETTING, METHODS Study participants were 49 males (aged 2 months to 36 years) and 57 females (aged 1 month to 37 years) with genetically confirmed diagnoses of PWS (deletions 60, uniparental disomy 54, imprinting center defect 2) followed in the Israel national multidisciplinary PWS clinic. MAIN RESULTS AND THE ROLE OF CHANCE Serum LH levels were in the normal range (1.0-6.0 mIU/ml) for 7/10 adult men, and high in 3, while FSH (normal range 1.0-6.1 mIU/ml) was elevated (34.4 ± 11.5 mIU/ml) in 6 and normal (3.5 ± 1.6 mIU/ml) in 4 men. Testosterone was low (5.7 ± 3.4 nmol/l) compared with the normal range of 12.0-34.5 nmol/l in the reference population in all men >20 years. AMH showed a normal decrease with age, despite low testosterone levels. Inhibin B was normal (241 ± 105 pg/ml) in infant boys, but low or undetectable in most adult men. Hormonal profiles were more heterogeneous in women than in men. Estradiol was consistently detectable in only 7/13 adult women. Inhibin B was low or undetectable in all PWS females although occasional samples showed levels within the normal range of 15-95 pg/ml. Vaginal bleeding was reported to occur for the first time in eight women at a median age of 20 years (13-34 years), but only one had regular monthly menses. The type of hypogonadism (primary or secondary) in PWS can be determined only after age 20 years. LIMITATIONS, REASONS FOR CAUTION The study cohort was heterogeneous, showing variability in BMI, cognitive disability and medical treatment. WIDER IMPLICATIONS OF THE FINDINGS Demonstration of the natural history of reproductive hormone development in PWS suggests that androgen replacement may be indicated for most PWS boys in mid-adolescence. Recommendations for hormone replacement in PWS women need to be individually tailored, serial measurements of inhibin B should be performed, and contraception should be considered in those women who may have the potential for fertility. STUDY FUNDING/COMPETING INTEREST(S) This study was supported by grants from Pfizer Pharmaceuticals and from the Foundation for Prader-Willi Research. T. Eldar-Geva and V. Gross-Tsur received grant/research support funding from the Foundation for Prader-Willi Research and from Pfizer Pharmaceuticals. TRIAL REGISTRATION NUMBER Not applicable. © 2015 The Author 2015. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: [email protected] /* */
    No preview · Article · Sep 2015 · Human Reproduction
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    ABSTRACT: Hyperphagia, low resting energy expenditure, and abnormal body composition contribute to severe obesity in Prader Willi syndrome (PWS). Irisin, a circulating myokine, stimulates "browning" of white adipose tissue resulting in increased energy expenditure and improved insulin sensitivity. Irisin has not been previously studied in PWS. Compare plasma and salivary irisin in PWS adults and normal controls. Examine the relationship of irisin to insulin sensitivity and plasma lipids. A fasting blood sample for glucose, lipids, insulin, leptin, adinopectin, and irisin was obtained from 22 PWS adults and 54 healthy BMI-matched volunteers. Saliva was collected for irisin assay in PWS and controls. Fasting glucose (77±9 vs 83±7mg/dl, p = 0.004), insulin (4.1±2.0 vs 7.9±4.7μU/ml, p<0.001), and triglycerides (74±34 vs 109±71mg/dl, p = 0.007) were lower in PWS than in controls. Insulin resistance (HOMA-IR) was lower (0.79±0.041 vs 1.63±1.02, p<0.001) and insulin sensitivity (QUICKI) was higher (0.41±0.04 vs 0.36±0.03, p<0.001) in PWS. Plasma irisin was similar in both groups, but salivary irisin (64.5±52.0 vs 33.0±12.1ng/ml), plasma leptin (33.5±24.2 vs 19.7±19.3ng/ml) and plasma adinopectin (13.0±10.8 vs 7.6±4.5μg/ml) were significantly greater in PWS (p<0.001). In PWS, plasma irisin showed positive Pearson correlations with total cholesterol (r = 0.58, p = 0.005), LDL-cholesterol (r = 0.59, p = 0.004), and leptin (r = 0.43, p = 0.045). Salivary irisin correlated negatively with HDL-cholesterol (r = -0.50, p = 0.043) and positively with LDL-cholesterol (r = 0.51, p = 0.037) and triglycerides (r = 0.50, p = 0.041). Salivary irisin was markedly elevated in PWS although plasma irisin was similar to levels in controls. Significant associations with plasma lipids suggest that irisin may contribute to the metabolic phenotype of PWS.
    Preview · Article · Sep 2015 · PLoS ONE
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    ABSTRACT: To determine the prevalence and characteristics of copy number variations (CNVs) in children with cerebral palsy (CP) of unknown etiology, comprising approximately 20% of the CP population. Fifty-two participants (age 10.5 ± 7.8 years; Gross Motor Function Classification System scale 2.8 ± 1.3) with nonprogressive pyramidal and/or extrapyramidal signs since infancy and no identified etiology were enrolled. Individuals with evidence of acquired causes were excluded. Participants underwent neurologic and clinical genetic examinations before the genomic testing. Chromosomal microarray analysis to detect CNVs was performed using the Affymetrix platform. CNVs identified were classified as pathogenic, likely pathogenic, likely benign, or benign. Only pathogenic and likely pathogenic CNVs were defined as clinically significant. Thirty-nine CNVs were found in 25 of 52 participants (48%). Sixteen participants (31%) had clinically significant CNVs: 10 pathogenic and 6 likely pathogenic, of which 7 were not previously associated with motor disability. Nine participants had likely benign CNVs. Clinically significant CNVs were more frequently de novo (12/16; p < 0.001) including in 5 of 8 individuals who had a first- or second-degree relative with a major neurologic disorder. Dysmorphic features and nonmotor comorbidities were more prevalent in individuals with clinically significant CNVs (p < 0.05 for both). CNVs, most frequently de novo, are common in individuals with cryptogenic CP. We recommend CNV testing in individuals with CP of unknown etiology. © 2015 American Academy of Neurology.
    Full-text · Article · Mar 2015 · Neurology
  • Talia Eldar-Geva · Harry J Hirsch · Varda Gross-Tsur
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    ABSTRACT: Prader-Willi syndrome (PWS) is a genetic syndrome caused by the lack of expression of imprinted genes located on paternal chromosome 15q11-q13, characterized by endocrine defects, an insatiable appetite, short stature, cognitive and behavioral difficulties and dysmorphic features. Nearly all PWS males and most PWS women show clinical and/or laboratory evidence of hypogonadism, affecting their habitus, health and quality of life. Until recently, hypogonadism in PWS was generally considered to be of centrall, hypothalamic origin. However, recent studies have shown that primary gonadal dysfunction is the major contributor to hypogonadism in this condition, while severe gonadotropin deficiency is rare. Despite clinical and laboratory evidence of hypogonadism, young adult PWS men and women have sexual and romantic interests and aspirations. Pregnancies have been reported in a few women with genetically documented PWS. Fertility has not been reported in PWS men. Recognition of these interests is essential for physicians and caregivers in order to offer proper anticipatory guidance, psychological and sex education and counseling. Individual variations in pubertal development, reproductive hormone profiles, bone-mineral density and individual appeal need to be considered when recommending sex hormone replacement in this population. Testosterone should be considered in most hypogonadal PWS males, considering possible side effects. Hormone replacement may be indicated in PWS women with decreasing bone mineral density or in PWS women who wish to have regular menses. Contraception should be considered in women with normal inhibin B levels. Hormone replacement is likely to improve bone density, quality of life and body image.
    No preview · Article · Mar 2015 · Harefuah
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    ABSTRACT: Objective: Prader-Willi syndrome (PWS) is a genetic multisystem disorder with various medical, cognitive, behavioral and psychiatric problems. PWS is caused by the lack of expression of paternal genes on chromosome 15q2-q13 due to a deletion (70-75%), uniparental disomy (25-30%) or imprinting center defect (<5%). The common PWS behavioral and psychiatric characteristics are very typical in all ethnicities and were reported worldwide. Still, each individual has a specific profile of these common traits and the severity of his or her symptoms varies over time. Behavioral problems are the most important factor affecting the quality of life of both the individuals and their families. There is a need for a standardized tool to assess the specific behavioral profile of each individual and its present severity, in order to enable physicians to tailor the specific treatment needed and assist in a more accurate clinical follow up. To the best of our knowledge no such a tool has been standardized and published. We developed, based on the literature (mainly Forster and Gourash's paradigm) and our clinical experience, a 37 item disease specific questionnaire, the "PWS Behavioral Questionnaire" (PWSBQ) for assessing behavior in PWS patients. The purpose of the present study was to validate this tool in the entire adolescent and adult PWS population in Israel. Methods: The PWSBQ focuses on five major domains-abnormal emotional regulation, food-seeking related behavior, lack of flexibility, oppositional behavior and interpersonal problems and lastly body related behaviors. Caregivers of all Hebrew speaking individuals with PWS over the age of 12 years attending the Israeli national multidisciplinary PWS clinic were recruited. Of the 54 eligible individuals, 53 participated. They were interviewed with the PWSBQ and in addition filled the "Hyperphagia Questionnaire" and the "Child Behavioral Checklist" (CBCL). After verifying the questionnaire's content validity, all items on the PWSBQ were analyzed for internal reliability by calculating Cronbach's α. Criterion validity was evaluated by correlation testing with regard to the Hyperphagia Questionnaire and CBCL. In order to assess the questionnaire's interpretability, the correlation between the PWSBQ and the "Clinical Global Impression" (CGI) scores was evaluated. Results: The PWSBQ total score was positively correlated with both the CBCL total score and the CGI score (0.662 and 0.549, p<0.001 respectively). Of the five domains, four had acceptable internal reliability (excluding the body related behaviors domain, which was thus removed from the total score). Criterion validity was established for the four domains remaining in the statistical analysis (abnormal emotional regulation, food seeking related behavior, lack of flexibility and oppositional behavior and interpersonal problems). Conclusions: Our findings suggest that the PWSBQ is a valid and reliable tool for the assessment of current behavioral problems among individuals with PWS. Although further research is needed in order to verify PWSBQ's ability to identify changes in the behavioral status of a given individual, it can now be used both in research and in a clinical setting, enabling the physician to plan the most suitable treatment based on the current behavioral status.
    No preview · Article · Dec 2014 · Comprehensive Psychiatry
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    Preview · Article · Oct 2014
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    ABSTRACT: Objective: Obsessive-compulsive disorder (OCD) and Tourette's syndrome are highly heritable neurodevelopmental disorders that are thought to share genetic risk factors. However, the identification of definitive susceptibility genes for these etiologically complex disorders remains elusive. The authors report a combined genome-wide association study (GWAS) of Tourette's syndrome and OCD. Method: The authors conducted a GWAS in 2,723 cases (1,310 with OCD, 834 with Tourette's syndrome, 579 with OCD plus Tourette's syndrome/chronic tics), 5,667 ancestry-matched controls, and 290 OCD parent-child trios. GWAS summary statistics were examined for enrichment of functional variants associated with gene expression levels in brain regions. Polygenic score analyses were conducted to investigate the genetic architecture within and across the two disorders. Results: Although no individual single-nucleotide polymorphisms (SNPs) achieved genome-wide significance, the GWAS signals were enriched for SNPs strongly associated with variations in brain gene expression levels (expression quantitative loci, or eQTLs), suggesting the presence of true functional variants that contribute to risk of these disorders. Polygenic score analyses identified a significant polygenic component for OCD (p=2×10(-4)), predicting 3.2% of the phenotypic variance in an independent data set. In contrast, Tourette's syndrome had a smaller, nonsignificant polygenic component, predicting only 0.6% of the phenotypic variance (p=0.06). No significant polygenic signal was detected across the two disorders, although the sample is likely underpowered to detect a modest shared signal. Furthermore, the OCD polygenic signal was significantly attenuated when cases with both OCD and co-occurring Tourette's syndrome/chronic tics were included in the analysis (p=0.01). Conclusions: Previous work has shown that Tourette's syndrome and OCD have some degree of shared genetic variation. However, the data from this study suggest that there are also distinct components to the genetic architectures of these two disorders. Furthermore, OCD with co-occurring Tourette's syndrome/chronic tics may have different underlying genetic susceptibility compared with OCD alone.
    Full-text · Article · Aug 2014 · American Journal of Psychiatry
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    ABSTRACT: Background: Minipuberty describes transient activation of the hypothalamic-pituitary-gonadal axis occurring during the first few months of life. Hormone levels during minipuberty were described in only a few Prader-Willi syndrome (PWS) infant boys and have not been reported in PWS infant girls. Objectives: To measure gonadotropins and gonadal hormones in PWS male and female infants and assess gender-specific patterns of hormone secretion. Methods: Hormone levels in 14 (9 male, 5 female) PWS infants ages 1-3 months were compared with reference ranges for normal infants and in 44 prepubertal PWS children (27 female, 17 male). Results: Compared to prepubertal boys, hormone levels (median and range) for PWS infant boys were increased: LH 2.8 mIU/ml (1.2-6.2), FSH 4.4 mIU/ml (1.0-19.5), testosterone 4.0 nmol/l (3.0-7.0), inhibin B 219 pg/ml (141-325), and AMH 79 ng/ml (45-157). Hormone levels in infant girls were not significantly different from levels in prepubertal girls. LH, inhibin B, and AMH were higher in male infants than in female infants. LH/FSH ratios were 0.56 (0.24-1.77) in boys versus 0.09 (0.04-0.17) in girls (p = 0.003). Conclusions: Hormone levels in PWS infant boys are in the expected minipuberty range. By contrast, reproductive hormones in most PWS infant girls did not differ from levels in prepubertal girls. © 2014 S. Karger AG, Basel.
    No preview · Article · Aug 2014 · Hormone Research in Paediatrics
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    ABSTRACT: The neonatal period is considered to be essential for neurodevelopment and wellbeing throughout the life span, yet little is known about brain-behavior relationships in the neonatal period. The aim of this study was to evaluate the association between neonatal sensory-motor regulation and white-matter (WM) integrity of major fiber tracts in the neonatal period. We hypothesized that WM integrity of sensory-motor systems would predict neurobehavioral maturation during the first month of life. Forty-nine premature neonates underwent magnetic-resonance-imaging at term. Diffusion-tensor-imaging analysis was performed in major WM tracts along with repeated neonatal neurobehavioral evaluations assessing sensory reactivity and motor regulation. Difficulties in one or more behavioral sub-category, mostly in auditory and visual attention, hypotonicity and jitteriness, were documented in 78.3% infants at term. Sixty-six percent of infants experienced difficulties, mostly in auditory attention, head-neck control, hypotonicity and motor asymmetry, at 44 weeks. Attention difficulties were associated with reduced integrity of cerebral and superior cerebellar peduncles; while tonicity was associated with reduced integrity of the corpus-callosum and inferior-posterior tracts. Overall, results showed that early maturing tracts were related with the degree of typicality of sensory reactivity status while late maturing tracts were related with the degree of typicality of tonic regulation. WM integrity and maturation factors explained 40.2% of the variance in neurobehavior at 44 weeks. This study suggests that in preterm neonates, deviant sensory-motor reactivity can be detected very early in development in manners that are related to lower integrity/maturational level of early and late maturing fiber tracts.
    Full-text · Article · Aug 2014 · Neuropsychologia
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    ABSTRACT: OBJECTIVE Obsessive-compulsive disorder (OCD) and Tourette syndrome (TS) are heritable neurodevelopmental disorders with a partially shared genetic etiology. This study represents the first genome-wide investigation of large (>500 kb), rare (<1%) copy number variants (CNVs) in OCD and the largest genome-wide CNV analysis in TS to date. METHOD The primary analyses used a cross-disorder design for 2,699 case patients (1,613 ascertained for OCD, 1,086 ascertained for TS) and 1,789 controls. Parental data facilitated a de novo analysis in 348 OCD trios. RESULTS Although no global CNV burden was detected in the cross-disorder analysis or in secondary, disease-specific analyses, there was a 3.3-fold increased burden of large deletions previously associated with other neurodevelopmental disorders (p = .09). Half of these neurodevelopmental deletions were located in a single locus, 16p13.11 (5 case patient deletions: 0 control deletions, p = .08 in the current study, p = .025 compared to published controls). Three 16p13.11 deletions were confirmed de novo, providing further support for the etiological significance of this region. The overall OCD de novo rate was 1.4%, which is intermediate between published rates in controls (0.7%) and in individuals with autism or schizophrenia (2-4%). CONCLUSION Several converging lines of evidence implicate 16p13.11 deletions in OCD, with weaker evidence for a role in TS. The trend toward increased overall neurodevelopmental CNV burden in TS and OCD suggests that deletions previously associated with other neurodevelopmental disorders may also contribute to these phenotypes.
    Full-text · Article · Jun 2014 · Journal of the American Academy of Child and Adolescent Psychiatry
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    ABSTRACT: The outcome of premature infants with only diffuse excessive high signal intensity (DEHSI) is not clear. We explored the relationship between DEHSI, white matter (WM) diffusion characteristics, perinatal characteristics, and neurobehavioral outcome at 1 year in a homogenous group of preterm infants without major brain abnormalities. Fifty-eight preterm infants, gestational age 29 ± 2.6 weeks, underwent an MRI at term-equivalent age (TEA). Griffiths Mental Developmental Scales, neurological assessment, and Parental Stress Index (PSI) were performed at 1 year corrected age. These measures were compared between preterm infants according to DEHSI classification (none, mild, moderate). Diffusion tensor imaging was used in major WM volumes of interest to objectively measure the degree of WM maturation. No significant differences were detected in the perinatal risk characteristics, neurobehavioral outcome, and PSI at 1 year between infants with different DEHSI classifications. In infants with DEHSI, increased axial and radial diffusivities were detected in the optic radiations, centrum semiovale, and posterior limb of the internal capsule, indicating less advanced maturation of the WM. Significant correlations were detected between the time interval from birth to MRI and the WM microstructure in infants without DEHSI. DEHSI in premature infants is neither a predictive measure for short-term adverse neurobehavioral outcome nor related to perinatal risk characteristics. Extrauterine exposure time had a differential effect on WM maturational trajectories in infants with DEHSI compared to those without. We suggest DEHSI may represent an alteration in WM maturational characteristics. Further follow-up studies may verify later consequences of DEHSI in premature infants.
    Full-text · Article · May 2014 · Neuroradiology
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    ABSTRACT: Objective: To compare echogenicity detected using cranial ultrasound (cUS) and diffuse excessive high signal intensity (DEHSI) detected using magnetic resonance imaging (MRI) by identical region-based scoring criteria in preterm infants. To explore the association between these white matter (WM) signal changes with early neurobehavior. Study design: Forty-nine pre-selected premature infants with only echogenicity on a first routine cUS1 underwent MRI and a repeated cUS2 at term equivalent age. Echogenicity and DEHSI were graded in various brain areas and diffusivity values were calculated. Neurobehavior was assessed using the Rapid Neonatal Neurobehavioral Assessment Procedure. Result: WM signal changes were significantly higher on cUS1 than cUS2; and higher in MRI than cUS2 in posterior regions. Infants with DEHSI demonstrated reduced tissue integrity. Imaging findings were not correlated with early neurobehavior. Conclusion: Echogenicity and DEHSI likely represent the same phenomenon. Reduction of over-interpretation of WM signal changes may help define criteria for the judicious use of imaging in routine follow-up of premature infants.
    Full-text · Article · Mar 2014 · Journal of perinatology: official journal of the California Perinatal Association
  • Naama Kroyzer · Varda Gross-Tsur · Yehuda Pollak
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    ABSTRACT: Risk taking is commonly attributed to individuals with attention deficit hyperactivity disorder (ADHD). This study investigated whether adolescents with ADHD would choose to take greater risks on a probabilistic task in which contingencies are explicitly presented. Adolescents with and without ADHD, aged 13 to 18 years, performed a modified version of the Cambridge Gambling Task. The subjects with ADHD risked smaller sums and chose the unfavorable outcomes more frequently than did the controls but had the same speed of decision and risk adjustment. The results indicate that their poor decisions were not due to impulsivity or insensitivity to the concept of probability and that increased risk taking is not always associated with ADHD. Moreover, in situations that do not demand learning of contingencies, ADHD may be associated with decreased, rather than increased, risk taking.
    No preview · Article · Mar 2014 · The Journal of nervous and mental disease
  • Varda Gross-Tsur · Harry Hirsch · Fortu Benarroch

    No preview · Article · Feb 2014 · The Israel Medical Association journal: IMAJ
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    ABSTRACT: Prader-Willi syndrome (PWS) is a neurodevelopmental disorder characterized by an insatiable appetite, dysmorphic features, cognitive and behavioral difficulties, and hypogonadism. The heterogeneous reproductive hormone profiles indicate that some PWS women may have symptoms of hypoestrogenism, while others may potentially be fertile. We describe our experience in the assessment and treatment of hypogonadism in adolescents and adult females with PWS. The study population consisted of 20 PWS females, age ≥16 years (27.3 ± 7.9 years), followed in our clinic (12 deletion, 7 uniparental disomy, 1 imprinting-center defect). General physical examination, pubertal assessment, body mass index (BMI), gynecological examination, ultrasonography, bone densitometry, and hormonal profiles [FSH, LH, inhibin B, estradiol, prolactin, and TSH] were performed. The relevant assessed factors were: FSH and inhibin B, menstrual cycles (oligo/amenorrhea or irregular bleeding), ultrasound findings (endometrial thickness, uterine/ovarian abnormalities), BMI, bone densitometry, and patient/caregivers attitude. We classified seven women with inhibin B >20 ng/ml as potentially fertile. Following the assessment of the above factors, we recommended the individual-specific treatment; contraceptive pills, intra-uterine device, estrogen/progesterone replacement, and cyclic progesterone, in 3, 1, 4, and 1 patients, respectively. Four patients did not follow our recommendations due to poor compliance or family refusal. We recommended contraception pills for one 26-year-old woman with inhibin B and FSH levels 53 ng/ml and 6.4 IU/L; however, she refused treatment, conceived spontaneously and had an abortion. Guidelines for hormonal replacement therapy in PWS need to be tailored individually depending on physical development, hormonal profiles, bone density, and emotional and social needs of each PWS adolescent and adult. © 2013 Wiley Periodicals, Inc.
    No preview · Article · Dec 2013 · American Journal of Medical Genetics Part A
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    ABSTRACT: The direct estimation of heritability from genome-wide common variant data as implemented in the program Genome-wide Complex Trait Analysis (GCTA) has provided a means to quantify heritability attributable to all interrogated variants. We have quantified the variance in liability to disease explained by all SNPs for two phenotypically-related neurobehavioral disorders, obsessive-compulsive disorder (OCD) and Tourette Syndrome (TS), using GCTA. Our analysis yielded a heritability point estimate of 0.58 (se = 0.09, p = 5.64e-12) for TS, and 0.37 (se = 0.07, p = 1.5e-07) for OCD. In addition, we conducted multiple genomic partitioning analyses to identify genomic elements that concentrate this heritability. We examined genomic architectures of TS and OCD by chromosome, MAF bin, and functional annotations. In addition, we assessed heritability for early onset and adult onset OCD. Among other notable results, we found that SNPs with a minor allele frequency of less than 5% accounted for 21% of the TS heritability and 0% of the OCD heritability. Additionally, we identified a significant contribution to TS and OCD heritability by variants significantly associated with gene expression in two regions of the brain (parietal cortex and cerebellum) for which we had available expression quantitative trait loci (eQTLs). Finally we analyzed the genetic correlation between TS and OCD, revealing a genetic correlation of 0.41 (se = 0.15, p = 0.002). These results are very close to previous heritability estimates for TS and OCD based on twin and family studies, suggesting that very little, if any, heritability is truly missing (i.e., unassayed) from TS and OCD GWAS studies of common variation. The results also indicate that there is some genetic overlap between these two phenotypically-related neuropsychiatric disorders, but suggest that the two disorders have distinct genetic architectures.
    Full-text · Article · Oct 2013 · PLoS Genetics
  • Tal Gilboa · Varda Gross-Tsur
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    ABSTRACT: Aim: The aim of the study was to characterize epilepsy, febrile seizures, electrographic features, and brain abnormalities in a large, national cohort of individuals with Prader-Willi syndrome (PWS). Method: This was an observational cohort study. Clinic charts of 126 individuals (63 males, 63 females) with genetically confirmed PWS (due to a deletion in 72 cases, to uniparental disomy [UPD] in 51 cases, and to an imprinting centre defect in two cases), aged from 1 month to 48 years (mean age 13y), were reviewed and 119 interviews conducted. Information regarding seizures, medication, imaging studies, and family history of seizures was collected. Ninety-five individuals (aged 1mo-48y) underwent electroencephalography (EEG). Results: Five individuals had epilepsy (4.0%), three of whom had major cerebral findings on imaging, and eight others had febrile seizures (6.4%). Of the three genetic abnormalities, deletion was associated with seizures. Focal epileptiform abnormalities were found in 12 out of 94 individuals, and five out of these 12 had a frank electrographic seizure pattern. Epileptogenic EEG abnormalities were associated with young age. Interpretation: The risk of epilepsy and febrile seizures in PWS is significantly lower than in Angelman syndrome and is associated with brain abnormalities. Electrographic seizures and focal epileptiform activity were present in 5% of individuals and were associated with young age. The underpinnings of epileptiform abnormalities in PWS and how they differ from those of the Angelman syndrome should be studied further.
    No preview · Article · Jun 2013 · Developmental Medicine & Child Neurology
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    ABSTRACT: This study investigated patterns of motor brain activation, white matter (WM) integrity of inter- and intrahemispheric connectivity and their associations with hand function in children with unilateral cerebral palsy (CP-U). Fourteen CP-U (mean age 10.6 ± 2.7 years) and 14 typically developing children (TDC) underwent magnetic resonance imaging. CP-U underwent extensive motor evaluation. Pattern of brain activation during a motor task was studied in 12 CP-U and six TDC, by calculating laterality index (LI) and percent activation in the sensorimotor areas (around the central sulcus), and quantifying the activation in the supplementary motor area (SMA). Diffusivity parameters were measured in CP-U and eight other TDC for the corpus callosum (CC), affected and less affected cortico-spinal tracts (CST), and posterior limb of the internal capsule (PLIC). Abnormal patterns of brain activation were detected in areas around the central sulcus in 9/12 CP-U, with bilateral activation and/or reduced percent activation. More activation in areas around the central sulcus of the affected hemisphere was associated with better hand function. CP-U demonstrated more activation in the SMA when moving the affected hand compared to the less affected hand. CP-U displayed reduced WM integrity compared to TDC, in the midbody and splenium of the CC, affected CST and affected PLIC. WM integrity in these tracts was correlated with hand function. While abnormal pattern of brain activation was detected mainly when moving the affected hand, the integrity of the CC was correlated with function of both hands and bimanual skills. This study highlights the importance of interhemispheric connectivity for hand function in CP-U, which may have clinical implications regarding prognosis and management.
    Full-text · Article · Apr 2013 · Brain Structure and Function
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    ABSTRACT: Purpose: Prolonged febrile seizures (PFS) lasting ≥15 min have been associated with increased risk for epilepsy in later life. Initial treatment, mostly prehospital, aims to prevent its evolution to febrile status epilepticus (FSE) and reduce adverse outcome. Paucity of information is available on the immediate treatment before reaching a hospital facility. Methods: We obtained data, prospectively, on all children who presented from January 2008 to March 2010 with PFS to the emergency rooms of four Israeli medical centers. Information related to seizure semiology, treatment, and medical history was collected into a predefined pro forma form and reviewed centrally. Key findings: Sixty children, median age 18.3 months (interquartile range [IQR] 12-28) were included with a median seizure duration of 35 min (IQR 26-60), 43 (71.7%) lasting ≥30 min. Seizures had focal onset in 34 infants (57%). Fifty-four families (90%) activated the ambulance service; median ambulance arrival time was 8 min (IQR 5-10), 33 (61%) were medically treated by the ambulance paramedic, of whom 15 (45%) responded to treatment. Twelve children with active seizures did not receive medications. Initial treatment with rectal diazepam was more common in those with seizure duration >30 min. Significance: Most children with PFS are treated with antiepileptic drugs early by the ambulance service. However, even timely treatment does not prevent status epilepticus in the majority of cases. These data highlight the need for effective early treatment of this common pediatric emergency.
    No preview · Article · Apr 2013 · Epilepsia
  • H.J. Hirsch · T. Eldar-Geva · V. Gross-Tsur
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    ABSTRACT: Nearly all PWS males and most PWS women show clinical and/or laboratory evidence of hypogonadism affecting their appearance, medical condition, and quality of life. Primary gonadal dysfunction is a major contributor to hypogonadism in this condition while severe gonadotropin deficiency is rare. In spite of their hypogonadism, adolescents and adults with PWS express a strong interest in sexual and romantic thoughts and activities. Recognition of these interests is essential for physicians and caregivers in order to offer proper anticipatory guidance, counseling and sex education. PWS men are likely to benefit from androgen replacement, but the impact on behavior may be a limitation. In women, individual reproductive hormone profiles, particularly inhibin B levels, may indicate potential fertility. Appropriate hormone replacement, or contraception when indicated, should be considered. Hormone replacement therapy is likely to improve bone mineral density and may have beneficial effects on body image and quality of life.
    No preview · Article · Jan 2013

Publication Stats

3k Citations
383.18 Total Impact Points

Institutions

  • 2004-2015
    • Hebrew University of Jerusalem
      • • Faculty of Medicine
      • • Department of Pediatrics
      • • Department of Psychology
      Yerushalayim, Jerusalem, Israel
  • 1991-2015
    • Shaare Zedek Medical Center
      • • Neuropediatric Unit
      • • Department of Pediatrics
      Yerushalayim, Jerusalem, Israel
  • 1990-1992
    • Bikur Holim Hospital,
      Yerushalayim, Jerusalem, Israel