Neuroscience Letters 591 (2015) 149–154

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Research article

Exome sequencing identifies SUCO mutations in mesial temporal lobe epilepsy Zhiqiang Sha a,1 , Longze Sha a,1 , Wenting Li a , Wanchen Dou b , Yan Shen a , Liwen Wu b,∗∗ , Qi Xu a,∗ a National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Tsinghua University, Beijing 10005, China b Department of Neurology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Science, Beijing 100730, China

h i g h l i g h t s • • • •

mRNA expression profiles divides the patients into two groups, severely and mildly affected patients, which are consistent with clinical phenotype. Exome sequencing results show that a novel mutant gene, SUCO, is shared by these severely affected patients. Knocking down SUCO expression in neurons impairs dendritic growth and development. SUCO colocalizes with rough endoplasmic reticulum in neurons.

a r t i c l e

i n f o

Article history: Received 7 January 2015 Received in revised form 5 February 2015 Accepted 6 February 2015 Available online 7 February 2015 Keywords: Mesial temporal lobe epilepsy Whole-exome sequencing Dendritic formation

a b s t r a c t Mesial temporal lobe epilepsy (mTLE) is the main type and most common medically intractable form of epilepsy. Severity of disease-based stratified samples may help identify new disease-associated mutant genes. We analyzed mRNA expression profiles from patient hippocampal tissue. Three of the seven patients had severe mTLE with generalized-onset convulsions and consciousness loss that occurred over many years. We found that compared with other groups, patients with severe mTLE were classified into a distinct group. Whole-exome sequencing and Sanger sequencing validation in all seven patients identified three novel SUN domain-containing ossification factor (SUCO) mutations in severely affected patients. Furthermore, SUCO knock down significantly reduced dendritic length in vitro. Our results indicate that mTLE defects may affect neuronal development, and suggest that neurons have abnormal development due to lack of SUCO, which may be a generalized-onset epilepsy-related gene. © 2015 Elsevier Ireland Ltd. All rights reserved.

1. Introduction Epilepsy is one of the most common neurological disorders, affecting 50 million people worldwide [21,24]. The patients may face cognitive impairments and behavioral abnormalities [3,6]. Genetic variants can influence occurrence and development of mTLE, including seizure onset, clinical endophenotypes [9]. In mTLE patients, mutant genes have been identified that encode neuronal membrane ion channels and neurotransmitter transporters, for

∗ Corresponding author. Tel.: +86 10 69156432; fax: +86 1065263392. ∗∗ Corresponding author. Tel.: +86 10 69156371; fax: +86 10 69156371. E-mail addresses: [email protected] (L. Wu), [email protected], [email protected] (Q. Xu). 1 These authors contributed equally to this work. http://dx.doi.org/10.1016/j.neulet.2015.02.009 0304-3940/© 2015 Elsevier Ireland Ltd. All rights reserved.

example GABBR1 [7,14,28], 1L-1ˇ [12,15], 1L-˛ [12], 1L-1R˛ [12], and PYDN[13,25]. Recently, monogenic inheritance studies have suggested a close relationship between disease occurrence and rare gene variants modified by high-risk genetic variants [26]. For example, some cases of autism, epilepsy, and schizophrenia are caused by rare genetic structural variants [23]. Thus, we applied exome sequencing to epilepsy and identified rare disease-related variants. Patients with mTLE are classified by different methods according to etiology or clinical phenotype. Severely affected patients are characterized by generalized-onset convulsions and consciousness loss. Several genes are involved in pathogenesis of different types of epilepsy [16], suggesting that patients with similar genetic variants may have similar disease severities. In this study, we identified epilepsy-related genes combined mRNA expression profiling with exome sequencing. In addition, we determined if the

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Table 1 Clinical features of the mTLE-HS and control groups. Patient no

Sex

Age

Time since the first seizure

No. of seisures/month

Pathology

Early risk factors

Medication

1

M

20

15

2-3 (Partial Seizures)

HS-R

No

2

F

33

24

3-4 (Partial Seizures)

HS-L

Cerebral cysticercosis

8 9

M F

23 23

10 14

1-2 (generalized seizures) 5-10 (paroxysmal stare gaze)

HS-L HS-L

Epidemic encephalitis Cerebral cysticercosis

16

F

47

26

3-4 (Partial Seizures)

HS-R

No

17 18

M M

29 22

1 2

4-5 (generalized seizures) 1-2 (generalized seizures)

HS-L HS-L

No No

Topiramate, Magnesium Valproate, Lamotrigine, Carbamazepine Carbamazepine, Phenobarbital, Sodium Valproate, Promethazine, Topiramate, Oxcarbazepine, Midazolam Carbamazepine, Topiramate, Sodium Valproate Sodium Valproate, Carbamazepine, Oxcarbazepine, Topiramate Phenobarbital, Phenytoinum Natricum, Nitrazepamum, Carbamazepine, Topiramate Carbamazepine, Topiramate, Risperidone Clonazepam, Topiramate, Oxcarbazepine

Control no.

Sex

Age

Cause of death

1 2 3 4

M F F M

52 56 65 55

Acid base imbalance Breast cancer Respiratory failure Lung cancer

In the pathology of the patients, R or L represents that right or left hippocampal may be sclerosis from Functional Magnetic Resonance Imaging (fMRI) results.

identified disease-related gene provides novel insights into disease pathogenesis. Recent studies have suggested that mutant genes, such as 1L1ˇ and GABBR1, contribute to epileptogenesis [1,8]. Whole-exome sequencing and mRNA expression profiling may help us identify novel mutant genes and provide novel insights into understanding disease mechanisms.

College, and the ethics committee of the Peking Union Medical College Hospital. Informed consent was obtained from the families of all individuals prior to enrollment. 2.2. Samples Genomic DNA was extracted from lymphocytes harvested from venous blood samples by standard methods.

2. Material and methods 2.3. Total RNA isolation 2.1. Patients Seven unrelated Chinese patients were diagnosed as having mTLE through clinical features and characteristic patterns on EEG. Experimental protocols were approved by the Ethics Committee of Chinese Academy of Medical Sciences, Peking Union Medical

The hippocampus tissues obtained from surgery were immediately frozen in liquid nitrogen and stored at 4 ◦ C, and treated with 10% buffered formalin within 1 h after surgery, fixed no later than 48 h. For each sample, mRNA was extracted from patients’ tissue using gradient centrifugation and Trizol reagent

Fig. 1. Comparison of gene expression profiles of mTLE patients and controls and SUCO gene structure and conservation of affected amino acid residues of identified mutations. (A) Heat map displaying the most 20 up-regulated and most 20 down-regulated genes in mTLE patients compared to control cases. Hierarchical clustering analysis of the percentage of genes associated with a GO category. (B) Confirmation of the causative mutations using the Sanger sequencing. Alignment of the amino acid sequences for three novel mutation sites. These mutation sites (p.Cys47X, p.Gln1144Arg p.Arg645Trp) were highly conserved between different species. (GenBank accession No.: H. sapiens NP 055098.1, P. Troglodytes XP 514000.2, M. Mulatta XP 001100732.1, C. Lupus XP 537192.3, B. Taurus XP 003587114.2, M. Musculus NP 766233.2, R. Norvegicus NP 955435.1, G. gallus XP 422229.4).

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Fig. 2. SUCO functions in the development of dendrites and subcellular location of SUCO in rough ER. (A) Representative immunoblots of SUCO. (B) Quantification of shRNA effect on the knockdown of SUCO. SUCO protein levels were normalized to actin. (C) Knockdown of SUCO caused a significant decrease in the length of dendrites. Cultured cortical primary neurons were infected with the control or shSUCO lentivirus. Six days later, neurons were fixed and immunostained with MAP2(the dendritic marker), quantified to determine the dendritic length. Scale bar represents 10 ␮m. (D) Quantification of normalized dendritic length. ** indicates p < 0.05, *** indicates p < 0.01, paired t test. Data are means, with error bars representing ±SEM from three experiments; total numbers of neurons analyzed (n) about 90 cells per condition. (E) Cultured cortical neurons immunostained with anti-Calnexin. SUCO colocalized with Calnexin(a marker for rough ER). Scale bar represents 10 ␮m.

(Invitrogen) recommended by the manufacturer for RNA extraction from hippocampus tissues. RNA quantification was assessed using Nanodrop spectrophotometer and Gel electrophoresis. 2.4. Whole exome sequencing We enriched exonic sequences using Agilent SureSelect technology for targeted exon capture, targeting 50Mb of sequence from exons. Samples were pooled and sequenced on one lane of an Illumina GAII × sequencing instrument [4]. On average, we generated 10Gb of sequence per sample to a mean depth of 80 × or greater to achieve exome builds with at least 98% of the exons covered by high quality genotype calls. The variants were filtered according to the variant function class, presence and frequency in the dbSNP132 and NHLB1 databases [10]. We included nonsynonymous, splice, frameshifting, nonsense variants and short insertions or deletions (indels) as potential mutations but excluded dbSNP variants. We used control exome data to exclude homozygous variants or variants with £3/41% frequency. We also used dbSNP138 and Exac database to recheck the variants. All the candidate mutations detected by WES were confirmed by Sanger sequencing. 2.5. mRNA whole-genome microarray screening Whole genome expression analysis performed by using the Illumina BeadArray technology. The mRNA expression profile was obtained using the Illumina Total Prep RNA Amplification Kit (Ambion) and the HumanHT-12 v4 Expression BeadChip according to the manufacturer’s instructions. BeadChips were imaged using the Illumina BeadArray Reader and the Illumina GenemeStudio software was applied to assess fluorescent hybridization signals and to perform the quality control filters [18].

2.6. Microarray analysis and statistical analysis The mRNA Illumina data was normalized using the quantile algorithm, implemented in the Illumina Genemestudio software [2]. Background was normalized by the GenemeStudio software. Filtering criteria included an intensity value which was significantly different from that of background (p < 0.01) as measured by the detection p-value, a statistical measure embedded in the GenemeStudio software. Cluster analysis has been run with GenemeStudio Gene Expression module, generating a dendrogram based on the Pearson’s correlation coeffcient [18]. To predict the biological functions of the differentially expressed genes, Expression Analysis Systematic Explorer analysis based on the Gene Ontology (GO) database and DAVID (http://david.abcc.ncifcrf.gov) was performed, the percentage of genes in each category per total amount of genes in each cluster was counted. 2.7. Cortical neuron culture Cortical neurons were cultured from E15.5C57BL/6 J rats. Neurons were maintained in neurobasal medium (Invitrogen) supplemented with B27, glucose, glutamax, penicillin/streptomycin (Invitrogen). For polarity studies, neurons (1 × 105 cells per cm2 ) were infected with the respective viruses on the day of culturing [11]. 2.8. Lentiviral infection siRNA target sequences were selected through Invitrogen siRNA selection tool. dsDNA oligonucleotides were inserted into pGLV3/H1/GFP-Puro vector and verified by sequencing. Mouse SUCO was targeted for shRNA knockdown through the sequence

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Table 2 Summary of confirmed mutation genes in the patients of mTLE. Gene name

Function

Chromosome

GenBank accession No.

Patient ID

Mutation

Polyphen

Type

SUCO

SUN domain containing ossification factor

Required for bone modeling during late embryogenesis

1q24

NM 001282750.1

No.17 No.8 No.18

Probably damaging Benign Probably damaging

IGSF10

Immunoglobulin superfamily member 10

3q25.1

NM 001178145.1

No.2 No.16 No.8

Nonsense mutation Missense mutation Missense mutation Indel Indel Missense mutation

MLL3

Myeloid/lymphoid or mixed-lineage leukemia 3

7q36.1

NM 001197104.1

No.16 No.17 No.1

c.2702A>G p.Leu901Pro c.12649G>T p.Leu4217Met c.8347C>T p.Asp2783Asn

Possible damaging Possible damaging Possible damaging

Missense mutation Missense mutation Missense mutation

PCNT

Pericentrin

21q22.3

NM 006031.5

No.2 No.8 No.8 No.18

c.5710G>A p.Ala1904Thr c.4855A>G p.Thr1619Ala c.5737G>A p.Gly1913Arg c.2264T>G p.Met755Arg

Benign Benign Probably damaging Probably damaging

Missense mutation Missense mutation Missense mutation Missense mutation

PLEC

Plectin

8q24

NM 000445.4

No.1 No.8 No.18

c.8917C>T p.Asp2973Asn c.2197G>A p.Arg733Trp c.6064C>T p.Ala2022Thr

Benign Possible damaging Benign

Missense mutation Missense mutation Missense mutation

RP1L1

Retinitis pigmentosa 1-like 1

Involved in the maintenance of osteochondroprogenitor cells pool and the binding, or adhesion processes of cells Involved in leukemogenesis and developmental disorder, histone methyltransferase, component of the MLL2/3 complex MOPD2 disease, together with DISC1 in the microtubule network formation, preventing premature centrosome splitting Muscular dystrophy, interlinks intermediate filaments with microtubules and microfilaments Required for the differentiation of photoreceptor cells, OCMD disease

c.141C>A p.Cys47X c.3431A>G p.Gln1144Arg c.1933C>T p.Arg645Trp c.1747 1748delCA p.Thr584Serfs*5 c.6088 6089insAT p.Val2031Metfs*4 c.7459C>T p.Asp2487Asn

8p23.1

NM 178857.5

No.16 No.17 No.1

c.416 417insC p.Gly140Argfs*10 c.6833G>C p.Thr2278Ser c.2193G>C p.Asp731Glu

Probably damaging Benign Benign

Indel Homozygous mutation Missense mutation

GGACAATACTGTGAAAGAA. The scrambled shRNA construct was similarly constructed [17]. Vector particles were resuspended in Neurobasal medium and infected the neurons at DIV1 and analysed at DIV6 [27].

2.9. Dendrites imaging and analysis The dendrites of cortical cells were imaged on an PerkinElmer confocal microscope fitted with a 40 × lens. The length of dendritic segments were measured with the Simple Neurite Tracer plug-in in ImageJ [20]. Statistical analysis was performed on the Leica microscope by using GraphPad Prism 5.0. Statistical comparisons were made with Student’s t test. All data are reported as the mean ± standard error of the mean(SEM).

Probably damaging Probably damaging Benign

2.10. Immunocytochemistry Neurons were fixed in 4% paraformaldehyde, permeabilized in 0.25% Triton X -100 and blocked in 5% bovine serum albumin (BSA), 0.25% Triton X-100 in PBS. Primary antibodies were MAP2 (abcam, ab32454), Calnexin (Stressgen, ADI-SPA-860-D) and flag (Earthon, E022030-00). Fluorophore-conjugated secondary antibodies were from Invitrogen. Fluorescence imaging was performed on inverted laser scanning confocal microscopes (Olympus FV1000).

2.11. Quantitative immunoblot analysis Whole cell lysates ran on SDS-PAGE gels. The resulting gels were transferred to nitrocellulose membranes. Membranes were blocked in phosphate-buffered saline containing 5% milk and probed with SUCO(Sigma, HPA047251), ␤-actin(sigma, A1978)

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overnight at 4 ◦ C and detected with goat anti-mouse IgG secondary antibody(Promega, w4028) 3. Results 3.1. Clinical characteristics Characteristics of patients with mTLE were confirmed by two senior doctors following diagnosis protocols. We examined the predictive accuracy of profiles based on each clinical characteristic. The patient group included four males and three females, an average age of 25 years old, except for one patient who was 47 years old. None of the controls suffered from any CNS diseases. None of the patients had a family history of epilepsy. Moreover, the epilepsy had not been well controlled with classical anticonvulsant drugs targeting ion channels for many years. Three severely affected mTLE patients were characterized by generalized-onset convulsions and consciousness loss, occurring for more than 20 years, up to 10 times per year. Mildly affected patients had paroxysmal stare gaze for approximately 10 years, up to 2–5 times per month (Table 1). 3.2. Function prediction and hierarchical cluster analysis of mRNA expression profiles At the individual gene level, differential gene expression varies frequently, therefore we tested the assumption that gene expression profiles can discriminate between mildly and severely affected patients. We selected the 20 most up- and down-regulated genes to perform hierarchical cluster analysis of differentially expressed genes. Comparing transcriptome-wide gene expression profiles between controls and patients showed strict division into two groups (Fig. 1A). Strikingly, severely affected patients (Nos. 8, 17, and 18) clustered into a group, indicating very high genetic homogeneity. To predict biological functions of differentially expressed genes in each cluster, the 200 most up- and down-regulated genes were selected for analysis. Gene ontology (GO) analysis indicated altered gene function in neuronal projection and synaptic function at the nucleic acid level. Altered transcripts mostly corresponded to membrane distribution with potential genes located within membranes such as the plasma membrane and endoplasmic reticulum. 3.3. Exome sequencing identifies SUCO mutations We performed exome sequencing in all seven patients, and identified six mutant genes (SUCO, IGSF10, MLL3, PCNT, PLEC, and RP1L1) shared randomly by three of the seven samples. All variants detected were confirmed by Sanger sequencing. Potential pathogenic mutations in these 19 variants were considered, including three insertion/deletion (indel) variants, a homozygous variant (c.6833G > C), a nonsense mutation introducing a premature stop signal (c.141C > T), and 14 missense variants. None of the variants were reported in dbSNP132 or exome databases, and no silent mutations were identified. We also used dbSNP138 and Exac database to recheck the variants, and the results showed that these mutations were still rare gene variants (MAF < 1%). To prioritize the variants, possible effects of mutations were predicted using PolyPhen (Table 2). According to our mRNA expression profile analysis, three severely affected patients were likely to share similar genetic variants. Our exome-sequencing results showed that only SUCO variants were shared by these three patients. Genes with coding sequences (e.g. MLL3, PLEC, and PCNT) covering large chromosomal regions may exhibit random genetic variants within a background of complex genetic and environmental factors. However, we had no sufficient reason to suggest these genes were related to epileptogenesis. Since these variants were less likely to be deleterious, the identified mutations were not interpreted to be

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disease-causing. Therefore, we propose that SUCO was a temporal lobe epilepsy-related gene. In addition, the amino acid sequence of SUCO at mutation sites and surrounding regions was highly conserved across species (Fig. 1B). Based on our mRNA expression profile analysis, our results showed that SUCO may contribute to neuronal development. However, the function of SUCO was not yet well known and SUCO protein has not been associated with known neuronal development pathways. Thus, we performed in vitro experiments to determine if SUCO impacts upon neuronal development. To examine SUCO function in neurons, we used a plasmid-based method of RNA interference (RNAi) to acutely knock down SUCO expression. We screened several target sequences to reduce endogenous SUCO levels in neurons (Fig. 2A and B). SUCO knock down in primary neurons caused a striking dendritic phenotype characterized by short primary dendrites. These results suggest that SUCO RNAi impaired dendritic growth and development (Fig. 2C and D). Previous reports have shown that SUCO localizes to the endoplasmic reticulum (ER) in primary osteoblasts. To examine subcellular localization of neuronal SUCO, we overexpressed flag-tagged full-length SUCO at days in vitro (DIV 3), and performed flag antibody staining after 2 days. We found that in neurons, SUCO colocalized with an ER marker, calnexin (Fig. 2E).

4. Discussion The cost of whole-genome sequencing has rapidly decreased. However, for genetically and phenotypically heterogeneous genetic disorders, such as schizophrenia and epilepsy, wholeexome sequencing is more efficient with regards to accuracy and cost. Therefore, we performed mRNA expression profiling on stratified samples to improve genetic homogeneity, which we predict will help identify novel disease-related genes. As expected, hierarchical cluster analysis showed that mildly and severely affected patients are divided into different clusters. Changes in differential gene expression within groups were similar. Using whole-exome sequencing and mRNA expression profiling analysis, our study provides genetic evidence that SUCO may be a novel mTLE-related gene. Our SUCO RNAi experiments show reduced dendritic length, indicating that SUCO function may correlate with neuronal development and subsequent pathological changes in epilepsy. In familial and severe sporadic forms of epilepsy, many of the identified genes encode ion channels or other components of neuronal signaling, but in the vast majority of cases, the genetic cause is unknown [19]. Recently, an increasing number of cases show that neural disease occurrence correlates with rare gene variants modified by high-risk genetic variants [5]. Therefore, we combined whole-exome sequencing with mRNA expression profiling to identify rare variants in mTLE. We detected several genetic variants in SUCO, including one premature stop signal and two missense variants, which have not been previously reported in epilepsy research. We have not tested whether other family members carried SUCO mutations or not. Maybe we could identify de novo mutations in their parents. The mutant gene could be strengthened to be the susceptibility allele by the genetic investigation of the trio analysis. In the pedigree research of epilepsy, it will provide us with more evidence to confirm the relationship between SUCO and epilepsy. SUCO (NC 000001.10; also called C1orf9) localizes to chromosome 1q, and encodes the SUN domain-containing ossification factor with three classical domains including a conserved SUN domain (Sad1/UNC-84 homology), coiled-coil domain, and C terminal transmembrane domain. The protein localizes to the rough endoplasmic reticulum (rER), participates in protein synthesis and promotes osteoblast proliferation. SUCO homozygous knockout mice osteoblasts have a fibroblastic appearance with a scarce,

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discontinuous rER network. Genetic knock out of SUCO in mouse mostly causes neonatal lethality. Surviving mice show not only impaired skeletal development, but the potential neurological defects [22]. Maybe SUCO could correlate with the abnormal discharge of the neurons associated with the epilepsy. Even though expression profiling analysis shows that patients carrying nonsense variants do not have reduced gene expression, we suspect this may be due to low gene expression levels and heterozygous mutations. We also consider SUCO to be the disease-related gene. In conclusion, genetics plays an important role in describing pathogenic mechanisms. We used whole-exome sequencing and mRNA expression profiling to identify novel heterozygous mutations in SUCO that cause mTLE. Because of an effect on rER integrity, we hypothesis that during epileptogenesis these variants may affect the function of protein synthesis, folding, and modification. Therefore, our study provides novel understanding of epilepsy. Acknowledgments This work was supported by the National 973 Program (2013CB531301,2012CB517902),NSFC(31430048, 81471325) and PUMC Youth Fund (2012J09). We sincerely thank all the patients for their support and participation. We also thank the doctors from Department of Neurology, Peking Union Medical College Hospital, for their patient recruitment efforts. References [1] G. Avanzini, S. Franceschetti, M. Mantegazza, Epileptogenic channelopathies: experimental models of human pathologies, Epilepsia 48 (Suppl. 2) (2007) 51–64. [2] K.J. Baines, J.L. Simpson, L.G. Wood, R.J. Scott, P.G. Gibson, Transcriptional phenotypes of asthma defined by gene expression profiling of induced sputum samples, J. Allergy Clin. Immunol. 127 (2011) 153–160, 160 e151–15. [3] W.T. Blume, H.O. Luders, E. Mizrahi, C. Tassinari, W. van Emde Boas, J. Engel Jr., Glossary of descriptive terminology for ictal semiology: report of the ILAE task force on classification and terminology, Epilepsia 42 (2001) 1212–1218. [4] M. Choi, U.I. Scholl, W. Ji, T. Liu, I.R. Tikhonova, P. Zumbo, A. Nayir, A. Bakkaloglu, S. Ozen, S. Sanjad, C. Nelson-Williams, A. Farhi, S. Mane, R.P. Lifton, Genetic diagnosis by whole exome capture and massively parallel DNA sequencing, Proc. Nat. Acad. Sci. U. S. A. 106 (2009) 19096–19101. [5] E.T. Cirulli, D.B. Goldstein, Uncovering the roles of rare variants in common disease through whole-genome sequencing, Nat. Rev. Genet. 11 (2010) 415–425. [6] R.S. Fisher, W. van Emde Boas, W. Blume, C. Elger, P. Genton, P. Lee, J. Engel Jr., Epileptic seizures and epilepsy: definitions proposed by the international league against epilepsy (ILAE) and the international bureau for epilepsy (IBE), Epilepsia 46 (2005) 470–472. [7] A. Gambardella, I. Manna, A. Labate, R. Chifari, A. La Russa, P. Serra, R. Cittadella, S. Bonavita, V. Andreoli, E. LePiane, F. Sasanelli, A. Di Costanzo, M. Zappia, G. Tedeschi, U. Aguglia, A. Quattrone, GABA(B) receptor 1 polymorphism (G1465A) is associated with temporal lobe epilepsy, Neurology 60 (2003) 560–563. [8] I. Helbig, I.E. Scheffer, J.C. Mulley, S.F. Berkovic, Navigating the channels and beyond: unravelling the genetics of the epilepsies, Lancet Neurol. 7 (2008) 231–245.

[9] S.E. Heron, K.M. Crossland, E. Andermann, H.A. Phillips, A.J. Hall, A. Bleasel, M. Shevell, S. Mercho, M.H. Seni, M.C. Guiot, J.C. Mulley, S.F. Berkovic, I.E. Scheffer, Sodium-channel defects in benign familial neonatal-infantile seizures, Lancet 360 (2002) 851–852. [10] J.M. Hofstra, M.J. Coenen, M.M. Schijvenaars, J.H. Berden, J. van der Vlag, L.H. Hoefsloot, N.V. Knoers, J.F. Wetzels, T. Nijenhuis, TRPC6 single nucleotide polymorphisms and progression of idiopathic membranous nephropathy, PLoS One 9 (2014) e102065. [11] S. Jiao, Z. Li, Nonapoptotic function of BAD and BAX in long-term depression of synaptic transmission, Neuron 70 (2011) 758–772. [12] K. Kanemoto, J. Kawasaki, T. Miyamoto, H. Obayashi, M. Nishimura, Interleukin (IL) 1beta, IL-1alpha, and IL-1 receptor antagonist gene polymorphisms in patients with temporal lobe epilepsy, Ann. Neurol. 47 (2000) 571–574. [13] M.A. Kauffman, D. Consalvo, M.D. Gonzalez, S. Kochen, Transcriptionally less active prodynorphin promoter alleles are associated with temporal lobe epilepsy: a case-control study and meta-analysis, Dis. Markers 24 (2008) 135–140. [14] M.A. Kauffman, E.M. Levy, D. Consalvo, J. Mordoh, S. Kochen, GABABR1 (G1465A) gene variation and temporal lobe epilepsy controversy: new evidence, Seizure: J. Br. Epilepsy Assoc. 17 (2008) 567–571. [15] M.A. Kauffman, D.G. Moron, D. Consalvo, R. Bello, S. Kochen, Association study between interleukin 1 beta gene and epileptic disorders: a HuGe review and meta-analysis, Genet. Med. Off. J. Am. Coll. Med. Genet. 10 (2008) 83–88. [16] P. Kwan, S.C. Schachter, M.J. Brodie, Drug-resistant epilepsy, New Engl. J. Med. 365 (2011) 919–926. [17] C. Lois, E.J. Hong, S. Pease, E.J. Brown, D. Baltimore, Germline transmission and tissue-specific expression of transgenes delivered by lentiviral vectors, Science 295 (2002) 868–872. [18] F. Martinelli-Boneschi, C. Fenoglio, P. Brambilla, M. Sorosina, G. Giacalone, F. Esposito, M. Serpente, C. Cantoni, E. Ridolfi, M. Rodegher, L. Moiola, B. Colombo, M. De Riz, V. Martinelli, E. Scarpini, G. Comi, D. Galimberti, MicroRNA and mRNA expression profile screening in multiple sclerosis patients to unravel novel pathogenic steps and identify potential biomarkers, Neurosci. Lett. 508 (2012) 4–8. [19] M.H. Meisler, J. Kearney, R. Ottman, A. Escayg, Identification of epilepsy genes in human and mouse, Annu. Rev. Genet. 35 (2001) 567–588. [20] M.L. O’Sullivan, J. de Wit, J.N. Savas, D. Comoletti, S. Otto-Hitt, J.R. Yates 3rd, A. Ghosh, FLRT proteins are endogenous latrophilin ligands and regulate excitatory synapse development, Neuron 73 (2012) 903–910. [21] D.K. Pal, A.W. Pong, W.K. Chung, Genetic evaluation and counseling for epilepsy, Nat. Rev. Neurol. 6 (2010) 445–453. [22] M.L. Sohaskey, Y. Jiang, J.J. Zhao, A. Mohr, F. Roemer, R.M. Harland, Osteopotentia regulates osteoblast maturation, bone formation, and skeletal integrity in mice, J. Cell Biol. 189 (2010) 511–525. [23] P. Stankiewicz, J.R. Lupski, Structural variation in the human genome and its role in disease, Annu. Rev. Med. 61 (2010) 437–455. [24] P.D. Stenson, M. Mort, E.V. Ball, K. Howells, A.D. Phillips, N.S. Thomas, D.N. Cooper, The Human gene mutation database: 2008 update, Genome Med. 1 (2009) 13. [25] E. Stogmann, A. Zimprich, C. Baumgartner, S. Aull-Watschinger, V. Hollt, F. Zimprich, A functional polymorphism in the prodynorphin gene promotor is associated with temporal lobe epilepsy, Ann. Neurol. 51 (2002) 260–263. [26] S.L. Thein, S. Menzel, Discovering the genetics underlying foetal haemoglobin production in adults, Br. J. Haematol. 145 (2009) 455–467. [27] G.M. Thomas, T. Hayashi, S.L. Chiu, C.M. Chen, R.L. Huganir, Palmitoylation by DHHC5/8 targets GRIP1 to dendritic endosomes to regulate AMPA-R trafficking, Neuron 73 (2012) 482–496. [28] B. Xi, J. Chen, L. Yang, W. Wang, M. Fu, C. Wang, GABBR1 gene polymorphism(G1465A) isassociated with temporal lobe epilepsy, Epilepsy Res. 96 (2011) 58–63.

Exome sequencing identifies SUCO mutations in mesial temporal lobe epilepsy.

Mesial temporal lobe epilepsy (mTLE) is the main type and most common medically intractable form of epilepsy. Severity of disease-based stratified sam...
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