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Epicure Consortium,
Eminet Consortium,
Michael Steffens,
Costin Leu,
Ann-Kathrin Ruppert,
Federico Zara,
Pasquale Striano,
Angela Robbiano,
Giuseppe Capovilla,
Paolo Tinuper, [......],
Herbert Schulz,
Franz Rüschendorf,
Markus Leber,
Steffen M Pauck,
Holger Trucks,
Mohammad R Toliat,
Peter Nürnberg,
Giuliano Avanzini,
Bobby P C Koeleman,
Thomas Sander
[show abstract]
[hide abstract]
ABSTRACT: Genetic generalized epilepsies (GGEs) have a lifetime prevalence of 0.3% and account for 20-30% of all epilepsies. Despite their high heritability of 80%, the genetic factors predisposing to GGEs remain elusive. To identify susceptibility variants shared across common GGE syndromes, we carried out a two-stage genome-wide association study (GWAS) including 3020 patients with GGEs and 3954 controls of European ancestry. To dissect out syndrome-related variants, we also explored two distinct GGE subgroups comprising 1434 patients with genetic absence epilepsies (GAEs) and 1134 patients with juvenile myoclonic epilepsy (JME). Joint Stage-1 and 2 analyses revealed genome-wide significant associations for GGEs at 2p16.1 (rs13026414, P(meta) = 2.5 × 10(-9), OR[T] = 0.81) and 17q21.32 (rs72823592, P(meta) = 9.3 × 10(-9), OR[A] = 0.77). The search for syndrome-related susceptibility alleles identified significant associations for GAEs at 2q22.3 (rs10496964, P(meta) = 9.1 × 10(-9), OR[T] = 0.68) and at 1q43 for JME (rs12059546, P(meta) = 4.1 × 10(-8), OR[G] = 1.42). Suggestive evidence for an association with GGEs was found in the region 2q24.3 (rs11890028, P(meta) = 4.0 × 10(-6)) nearby the SCN1A gene, which is currently the gene with the largest number of known epilepsy-related mutations. The associated regions harbor high-ranking candidate genes: CHRM3 at 1q43, VRK2 at 2p16.1, ZEB2 at 2q22.3, SCN1A at 2q24.3 and PNPO at 17q21.32. Further replication efforts are necessary to elucidate whether these positional candidate genes contribute to the heritability of the common GGE syndromes.
Human Molecular Genetics 09/2012; · 7.64 Impact Factor
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Costin Leu,
Carolien G F de Kovel,
Federico Zara,
Pasquale Striano,
Marianna Pezzella,
Angela Robbiano,
Amedeo Bianchi,
Francesca Bisulli,
Antonietta Coppola,
Anna Teresa Giallonardo, [......],
Nerses Bebek,
Ugur Ozbek,
Anne Hempelmann,
Herbert Schulz,
Franz Rüschendorf,
Holger Trucks,
Peter Nürnberg,
Giuliano Avanzini,
Bobby P C Koeleman,
Thomas Sander
[show abstract]
[hide abstract]
ABSTRACT: Genetic generalized epilepsies (GGEs) have a lifetime prevalence of 0.3% with heritability estimates of 80%. A considerable proportion of families with siblings affected by GGEs presumably display an oligogenic inheritance. The present genome-wide linkage meta-analysis aimed to map: (1) susceptibility loci shared by a broad spectrum of GGEs, and (2) seizure type-related genetic factors preferentially predisposing to either typical absence or myoclonic seizures, respectively.
Meta-analysis of three genome-wide linkage datasets was carried out in 379 GGE-multiplex families of European ancestry including 982 relatives with GGEs. To dissect out seizure type-related susceptibility genes, two family subgroups were stratified comprising 235 families with predominantly genetic absence epilepsies (GAEs) and 118 families with an aggregation of juvenile myoclonic epilepsy (JME). To map shared and seizure type-related susceptibility loci, both nonparametric loci (NPL) and parametric linkage analyses were performed for a broad trait model (GGEs) in the entire set of GGE-multiplex families and a narrow trait model (typical absence or myoclonic seizures) in the subgroups of JME and GAE families.
For the entire set of 379 GGE-multiplex families, linkage analysis revealed six loci achieving suggestive evidence for linkage at 1p36.22, 3p14.2, 5q34, 13q12.12, 13q31.3, and 19q13.42. The linkage finding at 5q34 was consistently supported by both NPL and parametric linkage results across all three family groups. A genome-wide significant nonparametric logarithm of odds score of 3.43 was obtained at 2q34 in 118 JME families. Significant parametric linkage to 13q31.3 was found in 235 GAE families assuming recessive inheritance (heterogeneity logarithm of odds = 5.02).
Our linkage results support an oligogenic predisposition of familial GGE syndromes. The genetic risk factor at 5q34 confers risk to a broad spectrum of familial GGE syndromes, whereas susceptibility loci at 2q34 and 13q31.3 preferentially predispose to myoclonic seizures or absence seizures, respectively. Phenotype- genotype strategies applying narrow trait definitions in phenotypic homogeneous subgroups of families improve the prospects of disentangling the genetic basis of common familial GGE syndromes.
Epilepsia 02/2012; 53(2):308-18. · 3.96 Impact Factor
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Sarah von Spiczak,
Hiltrud Muhle,
Ingo Helbig,
Carolien G F de Kovel,
Jochen Hampe, Verena Gaus,
Bobby P C Koeleman,
Dick Lindhout,
Stefan Schreiber,
Thomas Sander,
Ulrich Stephani
[show abstract]
[hide abstract]
ABSTRACT: Photoparoxysmal response (PPR) is characterized by abnormal visual sensitivity of the brain to photic stimulation. Frequently associated with idiopathic generalized epilepsies (IGEs), it might be an endophenotype for cortical excitability. Transient receptor potential cation (TRPC) channels are involved in the generation of epileptiform discharges, and TRPC4 constitutes the main TRPC channel in the central nervous system. The present study investigated an association of PPR with sequence variations of the TRPC4 gene. Thirty-five single nucleotide polymorphisms (SNP) within TRPC4 were genotyped in 273 PPR probands and 599 population controls. Association analyses were performed for the broad PPR endophenotype (PPR types I-IV; n = 273), a narrow model of affectedness (PPR types III and IV; n = 214) and PPR associated with IGE (PPR/IGE; n = 106) for each SNP and for corresponding haplotypes. Association was found between the intron 5 SNP rs10507456 and PPR/IGE both for single markers (P = 0.005) and haplotype level (P = 0.01). Three additional SNPs (rs1535775, rs10161932 and rs7338118) within the same haplotype block were associated with PPR/IGE at P < 0.05 (uncorrected) as well as two more markers (rs10507457, rs7329459) located in intron 3. Again, the corresponding haplotype also showed association with PPR/IGE. Results were not significant following correction for multiple comparisons by permutation analysis for single markers and Bonferroni-Holm for haplotypes. No association was found between variants in TRPC4 and other phenotypes. Our results showed a trend toward association of TRPC4 variants and PPR/IGE. Further studies including larger samples of photosensitive probands are required to clarify the relevance of TRPC4 for PPR and IGE.
Neuromolecular medicine 09/2010; 12(3):292-9. · 5.00 Impact Factor
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[show abstract]
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ABSTRACT: The issue of phenomenology of mood disorders in epilepsy still remains controversial. It has been suggested that a subgroup of patients may develop an affective syndrome also known as interictal dysphoric disorder (IDD). However, the number of behavioral changes that may occur around the ictus needs to be taken into account for an accurate distinction between "true" psychiatric phenomenology and periictal phenomena. This study aimed at identifying clinical correlates of the IDD, with special attention to the relationship between symptoms and seizures.
A sample of 142 consecutive adult outpatients with epilepsy were assessed using the Interictal Dysphoric Disorder Inventory (IDDI), a 38-item, self-report questionnaire specifically developed to evaluate presence and severity of IDD symptoms as well as their habitual association with seizures (coded as before, after, during, or when seizure-free) and their duration.
IDD was diagnosed in 31 subjects but symptoms showed a clear-cut relationship with epileptic seizures in 54.8% of cases, leading to an operative distinction between true IDD and periictal dysphoric symptoms (PDS). There was no significant difference among patients with IDD, PDS, or those without psychopathology. In the IDD group, symptoms were chronic and unremitting in one-third of cases, with labile affective symptoms being correlated with age at onset of seizures (rho = -0.612, p = 0.020) and duration of the epilepsy (rho = 0.833, p < 0.001).
An operative distinction between IDD and PDS bears the opportunity to identify different clinical endophenotypes that may have different prognoses and require different treatment strategies.
Epilepsia 07/2010; 51(7):1139-45. · 3.96 Impact Factor
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Hiltrud Muhle,
Sarah von Spiczak, Verena Gaus,
Serife Kara,
Ingo Helbig,
Jochen Hampe,
Andre Franke,
Yvonne Weber,
Holger Lerche,
Ailing A Kleefuss-Lie,
Christian E Elger,
Stefan Schreiber,
Ulrich Stephani,
Thomas Sander
[show abstract]
[hide abstract]
ABSTRACT: GRM4 encoding the group III metabotropic glutamate receptor 4 (mGluR4), is located on the chromosomal segment 6p21.3 where tentative susceptibility loci for Juvenile Myoclonic Epilepsy (JME) and Photoparoxysmal Response (PPR) have been mapped. The present candidate gene study examined if variation in GRM4 confers susceptibility to IGE.
The case-control association sample included 564 unrelated IGE patients and 733 population controls of German descent. Association analysis was carried out for 17 single nucleotide polymorphisms (SNPs) covering the genomic GRM4 sequence for all IGE patients as well as for two common IGE subsyndromes [Juvenile Myoclonic Epilepsy (JME, n=215) and Childhood Absence Epilepsy (CAE, n=175)]. Sequence analysis was performed in 85 IGE and 42 PPR cases and 44 controls.
Nominally significant associations were detected between IGE and seven GRM4 SNPs (with P-values ranging from 0.037 to 0.0036), between JME and five SNPs (P=0.042-0.0106), and between CAE and two SNPs (P=0.0466-0.0021). Four novel SNPs were identified by sequence analysis.
Our association findings support the hypothesis that GRM4 sequence variants might confer low-risk effects to the etiology of IGE. A minor pathogenetic contribution of the examined variants is possible. These exploratory findings warrant further replication analyses.
Epilepsy research 03/2010; 89(2-3):319-26. · 2.48 Impact Factor
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Carolien G F de Kovel,
Holger Trucks,
Ingo Helbig,
Heather C Mefford,
Carl Baker,
Costin Leu,
Christian Kluck,
Hiltrud Muhle,
Sarah von Spiczak,
Philipp Ostertag, [......],
Andre Franke,
Stefan Schreiber,
Peter Nürnberg,
Christian E Elger,
Holger Lerche,
Ulrich Stephani,
Bobby P C Koeleman,
Dick Lindhout,
Evan E Eichler,
Thomas Sander
[show abstract]
[hide abstract]
ABSTRACT: Idiopathic generalized epilepsies account for 30% of all epilepsies. Despite a predominant genetic aetiology, the genetic factors predisposing to idiopathic generalized epilepsies remain elusive. Studies of structural genomic variations have revealed a significant excess of recurrent microdeletions at 1q21.1, 15q11.2, 15q13.3, 16p11.2, 16p13.11 and 22q11.2 in various neuropsychiatric disorders including autism, intellectual disability and schizophrenia. Microdeletions at 15q13.3 have recently been shown to constitute a strong genetic risk factor for common idiopathic generalized epilepsy syndromes, implicating that other recurrent microdeletions may also be involved in epileptogenesis. This study aimed to investigate the impact of five microdeletions at the genomic hotspot regions 1q21.1, 15q11.2, 16p11.2, 16p13.11 and 22q11.2 on the genetic risk to common idiopathic generalized epilepsy syndromes. The candidate microdeletions were assessed by high-density single nucleotide polymorphism arrays in 1234 patients with idiopathic generalized epilepsy from North-western Europe and 3022 controls from the German population. Microdeletions were validated by quantitative polymerase chain reaction and their breakpoints refined by array comparative genomic hybridization. In total, 22 patients with idiopathic generalized epilepsy (1.8%) carried one of the five novel microdeletions compared with nine controls (0.3%) (odds ratio = 6.1; 95% confidence interval 2.8-13.2; chi(2) = 26.7; 1 degree of freedom; P = 2.4 x 10(-7)). Microdeletions were observed at 1q21.1 [Idiopathic generalized epilepsy (IGE)/control: 1/1], 15q11.2 (IGE/control: 12/6), 16p11.2 IGE/control: 1/0, 16p13.11 (IGE/control: 6/2) and 22q11.2 (IGE/control: 2/0). Significant associations with IGEs were found for the microdeletions at 15q11.2 (odds ratio = 4.9; 95% confidence interval 1.8-13.2; P = 4.2 x 10(-4)) and 16p13.11 (odds ratio = 7.4; 95% confidence interval 1.3-74.7; P = 0.009). Including nine patients with idiopathic generalized epilepsy in this cohort with known 15q13.3 microdeletions (IGE/control: 9/0), parental transmission could be examined in 14 families. While 10 microdeletions were inherited (seven maternal and three paternal transmissions), four microdeletions occurred de novo at 15q13.3 (n = 1), 16p13.11 (n = 2) and 22q11.2 (n = 1). Eight of the transmitting parents were clinically unaffected, suggesting that the microdeletion itself is not sufficient to cause the epilepsy phenotype. Although the microdeletions investigated are individually rare (<1%) in patients with idiopathic generalized epilepsy, they collectively seem to account for a significant fraction of the genetic variance in common idiopathic generalized epilepsy syndromes. The present results indicate an involvement of microdeletions at 15q11.2 and 16p13.11 in epileptogenesis and strengthen the evidence that recurrent microdeletions at 15q11.2, 15q13.3 and 16p13.11 confer a pleiotropic susceptibility effect to a broad range of neuropsychiatric disorders.
Brain 10/2009; 133(Pt 1):23-32. · 9.46 Impact Factor
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Marco Mula,
Regina Jauch,
Andrea Cavanna,
Laura Collimedaglia,
Davide Barbagli, Verena Gaus,
Rebekka Kretz,
Michele Viana,
Roberto Cantello,
Francesco Monaco,
Bettina Schmitz
[show abstract]
[hide abstract]
ABSTRACT: Although several studies pointed out an association between depression and quality of life (QoL) of patients with epilepsy, data about manic/hypomanic symptoms (MHS) remain scanty. In this study, we sought to investigate their relationship with social and health-related QoL measures in patients with epilepsy.
Consecutive adult outpatients with epilepsy were assessed using the M.I.N.I. Plus version 5.0.0 and the QOLIE-31.
Among 117 evaluated patients, 17 fulfilled DSM-IV criteria for manic/hypomanic episodes. Patients with MHS, as compared to those without, showed lower scores in emotional well-being, energy and fatigue, medication effects, social function and total QOLIE score. However, there was no between-groups difference in educational achievements, employment status, living situation, comorbid psychiatric disorders, history of suicide or abuse of illicit drugs.
MHS are associated with poor QoL measures in patients with epilepsy, though without differences in educational achievements, employment status and independent living.
Seizure 07/2009; 18(7):530-2. · 1.80 Impact Factor
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Ingo Helbig,
Heather C Mefford,
Andrew J Sharp,
Michel Guipponi,
Marco Fichera,
Andre Franke,
Hiltrud Muhle,
Carolien de Kovel,
Carl Baker,
Sarah von Spiczak, [......],
Christian E Elger,
Peter Nürnberg,
Corrado Romano,
Alain Malafosse,
Bobby P C Koeleman,
Dick Lindhout,
Ulrich Stephani,
Stefan Schreiber,
Evan E Eichler,
Thomas Sander
[show abstract]
[hide abstract]
ABSTRACT: We identified 15q13.3 microdeletions encompassing the CHRNA7 gene in 12 of 1,223 individuals with idiopathic generalized epilepsy (IGE), which were not detected in 3,699 controls (joint P = 5.32 x 10(-8)). Most deletion carriers showed common IGE syndromes without other features previously associated with 15q13.3 microdeletions, such as intellectual disability, autism or schizophrenia. Our results indicate that 15q13.3 microdeletions constitute the most prevalent risk factor for common epilepsies identified to date.
Nature Genetics 02/2009; 41(2):160-2. · 35.53 Impact Factor
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Marco Mula,
Regina Jauch,
Andrea Cavanna,
Laura Collimedaglia,
Davide Barbagli, Verena Gaus,
Rebekka Kretz,
Michele Viana,
Grazia Tota,
Heike Israel,
Uwe Reuter,
Peter Martus,
Roberto Cantello,
Francesco Monaco,
Bettina Schmitz
[show abstract]
[hide abstract]
ABSTRACT: Different authors suggested the occurrence of a pleomorphic affective syndrome in patients with epilepsy named interictal dysphoric disorder (IDD). We sought to investigate whether IDD occurs only in patients with epilepsy and to validate IDD features against DSM-IV criteria.
Consecutive patients with a diagnosis of epilepsy (E) or migraine (M) have been assessed using the BDI, MDQ, and the Interictal Dysphoric Disorder Inventory (IDDI), a questionnaire specifically created to evaluate IDD symptoms. Diagnosis of current and lifetime DSM-IV Axis I disorders was established using the MINI Plus version 5.0.0.
A total of 229 patients (E = 117; M = 112) were evaluated. Females were significantly more represented in the migraine group (E = 46.5% vs. M = 73.3% p = 0.009), but there was no difference in age, duration of the disease, or education level. Patients with epilepsy were more likely to screen positively at MDQ (E = 17% vs. M = 5.3% p = 0.006) and to have a diagnosis of bipolar disorder (E = 14.5% vs. M = 4.5% p = 0.013) as compared to migraine patients. There was no between-groups difference in IDD prevalence (E = 17%; M = 18.7%) and IDDI total scores (E = 4.1 +/- 2.0 vs. M = 3.8 +/- 2.0). Validation of IDD against DSM-IV categories showed current major depression being the foremost diagnostic category correlated with IDD in both epilepsy (OR = 0.32-0.12-0.88, p = 0.028) and migraine (OR = 0.10, 95% CI = 0.02-0.49, p = 0.004) samples. Current anxiety disorder correlated with IDD only in migraine patients (OR = 0.19, 95% CI = 0.05-0.77, p = 0.02).
IDD represents a homogenous construct that can be diagnosed in a relevant proportion of patients but it is not typical only of epilepsy, occurring in other central nervous system disorders such as migraine.
Epilepsia 05/2008; 49(4):650-6. · 3.96 Impact Factor
