Marcelo Andrés Kauffman

Association study between interleukin 1β gene and epileptic disorders: a HuGe review and meta-analysis

Previous studies have examined the association of a single nucleotide polymorphism at the promoter region of interleukin 1B (IL-1β-511T) with temporal lobe epilepsy and febrile seizures susceptibility, but those studies have been inconclusive. Published studies up to March 2007 of temporal lobe epilepsy, febrile seizures and the IL-1β-511T single nucleotide polymorphism were identified by searches of Medline and Embase databases. Meta-analysis of temporal lobe epilepsy and febrile seizures case-control data were performed to assess the association of IL-1β-511T with temporal lobe epilepsy, temporal lobe epilepsy with hippocampal sclerosis, febrile seizures, and other epileptic disorders. Pooled odds ratios (OR) were estimated by means of a genetic-model-free approach. The quality of the included studies was assessed by a score. The results show a modest association (OR, 1.48; 95% confidence interval, 1.09–2.00; P = 0.01) between the IL-1β-511T polymorphism and temporal lobe epilepsy with hippocampal sclerosis.

Whole Genome Sequencing Reveals a De Novo SHANK3 Mutation in Familial Autism Spectrum Disorder

Introduction Clinical genomics promise to be especially suitable for the study of etiologically heterogeneous conditions such as Autism Spectrum Disorder (ASD). Here we present three siblings with ASD where we evaluated the usefulness of Whole Genome Sequencing (WGS) for the diagnostic approach to ASD. Methods We identified a family segregating ASD in three siblings with an unidentified cause. We performed WGS in the three probands and used a state-of-the-art comprehensive bioinformatic analysis pipeline and prioritized the identified variants located in genes likely to be related to ASD. We validated the finding by Sanger sequencing in the probands and their parents. Results Three male siblings presented a syndrome characterized by severe intellectual disability, absence of language, autism spectrum symptoms and epilepsy with negative family history for mental retardation, language disorders, ASD or other psychiatric disorders. We found germline mosaicism for a heterozygous deletion of a cytosine in the exon 21 of the SHANK3 gene, resulting in a missense sequence of 5 codons followed by a premature stop codon (NM_033517:c.3259_3259delC, p.Ser1088Profs*6). Conclusions We reported an infrequent form of familial ASD where WGS proved useful in the clinic. We identified a mutation in SHANK3 that underscores its relevance in Autism Spectrum Disorder.

Serotonin transporter gene variation and refractory mesial temporal epilepsy with hippocampal sclerosis

We performed a molecular epidemiology study in a population of 105 mesial temporal lobe epilepsy with hippocampal sclerosis (MTE-HS) patients in order to investigate the role of a polymorphism in the serotonin transporter gene (SLC6A4) in the prediction of antiepileptic drug (AED) treatment response. Homozygous carriers of the 12-repeat allele had an almost fourfold increase in risk for a MTE-HS not responding to medical treatment (OR 3.88; CI 95% 1.40-10.7; p=0.006) compared to carriers of the 10-repeat allele. Therefore, a polymorphism of SLC6A4 might be a genetic marker of pharmacoresistance in MTE-HS patients.

The cerebellum and embodied semantics: evidence from a case of genetic ataxia due to STUB1 mutations

Fil: Garcia, Adolfo Martin. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto de Neurociencia Cognitiva y Traslacional. Fundacion Ineco Rosario Sede del Incyt | Instituto de Neurologia Cognitiva. Instituto de Neurociencia Cognitiva y Traslacional. Fundacion Ineco Rosario Sede del Incyt | Fundacion Favaloro. Instituto de Neurociencia Cognitiva y Traslacional. Fundacion Ineco Rosario Sede del Incyt; Argentina. Universidad Nacional de Cuyo; Argentina

ApoE ɛ4 genotype and the age at onset of temporal lobe epilepsy: A case–control study and meta-analysis

In order to investigate the role of ApoE epsilon4 as a modifier of the age at onset of temporal lobe epilepsy (TLE), we performed a molecular epidemiology study in 78 patients with mesial temporal lobe epilepsy and hippocampal sclerosis. Genotyping was done by a PCR-RFLP assay. In order to better estimate the role of this variant as a modifier of the age at onset, we also performed a systematic review of the literature. We included our results into a meta-analysis along with data available from seven published studies with 728 patients that looked into the role of ApoE epsilon4 in TLE. We found that ApoE epsilon4 carriers in our population had a non-significant earlier age of epilepsy onset than non-carriers. The meta-analysis confirmed this finding, showing that ApoE epsilon4 carriers had epilepsy onset almost 4 years earlier than non-carriers (mean difference 5.15 years; CI 95% 2.08-6.22; p=0.001). In conclusion, the ApoE epsilon4 isoform is a genetic factor that might influence the age at onset of TLE.

Transcriptionally less active prodynorphin promoter alleles are associated with Temporal Lobe Epilepsy: A case-control study and meta-analysis

We performed an association study in a population of patients with Mesial Temporal Lobe Epilepsy (TLE) with Hippocampal Sclerosis (MTEHS) together with a systematic revision of the literature to investigate the role of transcriptionally less active polymorphic alleles of Prodynorphin (PDYN) gene in this pathology. We included 102 patients with a diagnosis of MTEHS and 86 healthy controls. The positive antecedent of family history for epileptic events defined a TLE subgroup with familial predisposition for epileptic disorders. The PDYN promoter polymorphism was genotyped by means of a PCR assay. For meta-analysis, we identified case-control association studies between TLE and PDYN by searching PUBMED. The pooled OR was estimated using a fixed effects model under dominant and co-dominant heredity models. No differences in genotypic and allelic frequencies were found between cases and controls (p = 0.61) in our population, neither in the whole cohort nor in the analysis limited to TLE with familial predisposition (p = 0.71). The Meta-Analysis included 591 TLE patients and 1117 healthy controls. We found an association between L allele (p = 0.003; OR = 1.40; IC 95 = 1.12–1.74) and a modestly higher risk to develop TLE in the group of patients with familial predisposition. Therefore, functional allelic variants in the PDYN promoter might modify the risk to develop TLE in subjects with familial predisposition.

Ataxia plus myoclonus in a 23-year-old patient due to STUB1 mutations.

More than 1,000 mutations mapping to 60 different loci have been recognized as the cause of hereditary ataxias. However, almost 50% of the cases are still genetically uncharacterized, with etiology remaining to be identified.1 Diagnosis and research in rare diseases such as ataxia has been significantly improved with the recent availability of next-generation sequencing technologies.2 In order to expand the phenotype recently described in ataxia due to STUB1 mutations and to illustrate the utility of clinical genomics in the diagnosis of ataxias, we present a 23-year-old patient who had ataxia plus myoclonus in whom exome sequencing revealed novel compound heterozygous mutations in the STUB1 gene.

Diagnosis of mitochondrial disorders applying massive pyrosequencing

Mitochondrial disorders are a frequent cause of neurological disability affecting children and adults. Traditionally, molecular diagnosis of mitochondrial diseases was mostly accomplished by the use of Sanger sequencing and PCR–RFLP. However, there are particular drawbacks associated with the use of these methods. Recent multidisciplinary advances have led to new sequencing methods that may overcome these limitations. Our goal was to explore the use of a next generation sequencing platform in the molecular diagnosis of mitochondrial diseases reporting our findings in adult patients that present with a clinical-pathological diagnosis of a mitochondrial encephalomyopathy. Complete genomic sequences of mitochondrial DNA were obtained by 454 massive pyrosequencing from blood samples. The analysis of these sequences allowed us to identify two diagnostic pathogenic mutations and 74 homoplasmic polymorphisms, useful for obtaining high-resolution mitochondrial haplogroups. In summary, molecular diagnosis of mitochondrial disorders could be efficiently done from readily accessible samples, such as blood, with the use of a new sequencing platform.

GABABR1 (G1465A) gene variation and temporal lobe epilepsy controversy: New evidence

The G1465A polymorphism in the gene of the GABA type B receptor subunit 1 (GABABR1) has been linked to the risk for temporal lobe epilepsy (TLE). However, six replication studies did not show significant association between the G1465A GABABR1 gene variant and TLE. The authors examined this association in a sample of 102 patients with mesial TLE with hippocampal sclerosis (MTLE-HS) and 71 controls. The genotype distribution varied significantly between patients and controls. Heterozygous carriers of the A-allele had a 10-fold increase in risk for MTLE-HS (OR 10.01; 95% CI 3.98-25.18, p=3.788E-08).

ApoE ɛ4 is not associated with posictal confusion in patients with mesial temporal lobe epilepsy with hippocampal sclerosis

A previous report found an association between ApoE isoforms and postictal confusion in medically intractable temporal lobe epilepsy (TLE). We performed a molecular epidemiology study in an independent sample of 77 TLE patients. We failed to replicate the original allelic association between ApoE epsilon4 allele and postictal confusion in our population (chi(2)=1.67; d.f.=1; p=0.2). Thus, the association between ApoE epsilon4 allele and postictal confusion still needs to be fully investigated in different and independent populations.