Fayçal Mouaffak

De novo mutations in the gene encoding the synaptic scaffolding protein SHANK3 in patients ascertained for schizophrenia

Schizophrenia likely results from poorly understood genetic and environmental factors. We studied the gene encoding the synaptic protein SHANK3 in 285 controls and 185 schizophrenia patients with unaffected parents. Two de novo mutations (R1117X and R536W) were identified in two families, one being found in three affected brothers, suggesting germline mosaicism. Zebrafish and rat hippocampal neuron assays revealed behavior and differentiation defects resulting from the R1117X mutant. As mutations in SHANK3 were previously reported in autism, the occurrence of SHANK3 mutations in subjects with a schizophrenia phenotype suggests a molecular genetic link between these two neurodevelopmental disorders.

Mutations in SYNGAP1 in Autosomal Nonsyndromic Mental Retardation

Although autosomal forms of nonsyndromic mental retardation account for the majority of cases of mental retardation, the genes that are involved remain largely unknown. We sequenced the autosomal gene SYNGAP1, which encodes a ras GTPase-activating protein that is critical for cognition and synapse function, in 94 patients with nonsyndromic mental retardation. We identified de novo truncating mutations (K138X, R579X, and L813RfsX22) in three of these patients. In contrast, we observed no de novo or truncating mutations in SYNGAP1 in samples from 142 subjects with autism spectrum disorders, 143 subjects with schizophrenia, and 190 control subjects. These results indicate that SYNGAP1 disruption is a cause of autosomal dominant nonsyndromic mental retardation.

Association of Disrupted in Schizophrenia 1 (DISC1) missense variants with ultra-resistant schizophrenia.

Three common missense variants of the Disrupted in Schizophrenia 1 (DISC1) gene, rs3738401 (Q264R), rs6675281 (L607F) and rs821616 (S704C), have been variably associated with the risk of schizophrenia. In a case–control study, we examine whether these gene variants are associated with schizophrenia and ultra-resistant schizophrenia (URS) in a population of French Caucasian patients. The URS phenotype is characterized according to stringent criteria as patients who experience no clinical, social and/or occupational remission in spite of treatment with clozapine and at least two periods of treatment with distinct conventional or atypical antipsychotic drugs. We find a significant association between DISC1 missense variants and URS. The association with rs3738401 remains significant after appropriate correction for multiple testing. These results suggest that the DISC1 rs3738401 missense variant is statistically linked with ultra-resistance to antipsychotic treatment.

Family-based association study of common variants, rare mutation study and epistatic interaction detection in HDAC genes in schizophrenia.

BACKGROUND Histone deacetylases (HDACs) are key enzymes of histone acetylation, and abnormalities in histone modifications and in the level of HDAC proteins have been reported in schizophrenia. The objective of the present study was to systematically test the HDAC genes for its association with schizophrenia. METHODS A family-based genetic association study (951 Caucasian subjects in 313 nuclear families) using 601 tag-single nucleotide polymorphisms in HDAC genes was conducted followed by a replication study of top-ranked markers in a sample of 1427 Caucasian subjects from 241 multiplex families and 176 trios. Epistasis interaction was tested by using the pedigree-based generalized multifactor dimensionality reduction (GMDR). Furthermore, we analyzed exome sequencing data of 1134 subjects for detection of rare mutations in HDAC genomic regions. RESULTS In the exploratory study, ten markers were in significant association with schizophrenia (P<0.01). One maker rs14251 (HDAC3) was replicated (P=0.04) and remained significant in the whole sample (P=0.004). GMDR identified that a significant three-locus interaction model was detected involving rs17265596 (HDAC9), rs7290710 (HDAC10) and rs7634112 (HDAC11) with a good testing accuracy (0.58). No rare mutations were found associated with schizophrenia. CONCLUSION This first exploratory systematic study of the HDAC genes provides consistent support for the involvement of the HDAC3 gene in the etiology of schizophrenia. A statistical epistatic interaction between HDAC9, HDAC10, and HDAC11 was detected and seems biologically plausible.

Association of an UCP4 (SLC25A27) haplotype with ultra-resistant schizophrenia.

AIMS Neuronal uncoupling proteins are involved in the regulation of reactive oxygen species production and intracellular calcium homeostasis, and thus, play a neuroprotective role. In order to explore the potential consequences of neuronal uncoupling proteins variants we examined their association in a sample of Caucasian patients suffering from schizophrenia and phenotyped them according to antipsychotic response. MATERIALS & METHODS Using a case-control design, we compared the frequencies of 15 genetic variants spanning UCP2, UCP4 and UCP5 in 106 French Caucasian patients suffering from schizophrenia and 127 healthy controls. In addition, patients with schizophrenia who responded to antipsychotic treatment were compared with patients with ultra-resistant schizophrenia (URS). This latter population presented no clinical, social and/or occupational remission despite at least two periods of treatment with conventional or atypical antipsychotic drugs and also with clozapine. RESULTS There were no differences in the distribution of the respective alleles between URS and responding patients. However, one haplotype spanning UCP4 was found to be significantly under-represented in URS patients. This relationship remained significant after multiple testing corrections. CONCLUSION Although our sample is of limited size and not representative of schizophrenia as a whole, the association found between the URS group and the UCP4 haplotype is noteworthy as it may influence treatment outcome in schizophrenia.

Somatic augmentation strategies in clozapine resistance--what facts?

Background: Polypharmacy without evidence-based support is sometimes needed for patients treated with 40% to 70% clozapine who are clozapine nonresponders. Several somatic augmentation strategies are proposed in the scientific literature, with different levels of evidence for safety and efficacy. Objectives: The purpose of the present study is to review the available literature on the efficacy and safety of clozapine augmentation with somatic agents other than antipsychotics. The following classes of agents are considered: (1) mood stabilizers, (2) antidepressants, (3) electroconvulsive therapy and repetitive transcranial magnetic stimulation, (4) glutamatergic agents, (5)fatty acids supplements, and (6) benzodiazepines. Results: Case controls and small-size clinical trials largely dominate the literature, limiting the power to draw conclusions concerning safety issues and the meaning of negative studies. Moreover, variable definitions of clozapine resistance, heterogeneous outcome measures, and short duration of treatment trials are additional limitations. Conclusion: Generally, adjunctive strategies for clozapine-resistant patients remain based on scarce evidence of efficacy and significant safety concerns. Low-frequency repetitive transcranial magnetic stimulation, fatty acids supplements, and mirtazapine showed good tolerability and some efficacy, but the results need replication.

[Validation of the French version of the expanded Brief Psychiatric Rating Scale with anchor BPRS-E(A)].

INTRODUCTION The Brief Psychiatric Rating Scale was initially developed as a rapid method to assess symptom change in psychiatric inpatients of various diagnoses. The original version was expanded to an 18-item version and thereafter to a 24-item version to increase sensitivity to a broader range of psychotic and affective symptoms. The latest version of the expanded 24- item BPRS provides probe questions and detailed anchor points for the ratings for each item. LITERATURE FINDINGS Studies have shown the expanded and anchored 24-item BPRS to be a sensitive and effective measure of psychiatric symptoms with good interrater reliability that can be maintained over time. To our knowledge, there are eight published papers including factor analyses of the BPRS-E(A). While many similarities are evident between these studies, inconsistencies are apparent that may have been due to sample size, characteristics and / or methodological differences in the factor analysis computation. Among these studies, six provided a four-factor solution. There was no French version of this scale available. METHODS After its translation into French and back translation, we investigated the validity of the French BPRS-E(A) version. We carried out a component analysis on the data of 111 participants of various diagnoses, mostly hospitalised for a first psychotic episode, yielding to a three-factor solution (positive symptoms--disorganisation; depression-anxiety and negative symptoms). RESULTS A good internal consistency and interrater reliability were found. These results confirm the psychometric value of the BPRS-E(A) in its French version. We compared those findings to earlier reports; similarities and differences are discussed.

OSTA program: A French follow up intervention program for suicide prevention.

Attempted suicide is a strong risk factor for subsequent suicidal behavior. In recent years, a particular interest has been given to follow-up interventions as a potential effective strategy in preventing recurrent suicidal behavior. We developed a follow-up intervention program called OSTA (organization of a suitable monitoring for suicide attempters) aimed at addressing this issue and tested its effectiveness in a 1-year randomized controlled trial. Individuals who attempted suicide and were admitted to the emergency department (ED) of Bicêtre Hospital (n=320) were randomly allocated to receive either the OSTA program or a control treatment. On an intention to treat basis, the proportion of patients who reattempted suicide did not differ significantly between the interventional group (IG) 14.5% (22/152) and the control group (CG) 14% (21/150). There were also no significant differences, between the two arms, in the number of suicide attempts. Although no significant difference has been found between the OSTA program and the control treatment concerning the rate of suicide reattempts, we believe that further studies should be conducted to test the effectiveness of more standardized follow-up studies in suicide prevention.

Clozapine-Induced Serositis: Review of Its Clinical Features, Pathophysiology and Management Strategies

Although the benefits of clozapine have been well demonstrated in resistant schizophrenia, the frequency of adverse events is of particular concern: up to 76% of patients to whom clozapine was prescribed experienced an adverse event, with a discontinuation rate of 17%. In addition to its major clinical side effect, agranulocytosis, clozapine is reported to induce inflammatory syndromes with polyserositis. Apart from sparse case reports, no study has yet addressed this particularly interesting issue. With the aim of improving the outcome of clozapine-treated patients, we undertook a review of the literature to characterize the clinical features of clozapine-induced serositis, its pathophysiology, and to propose strategies of clinical management.

Differential Response to ECT of Psychotic and Affective Symptoms in Huntington’s Disease: A Case Report

To the Editor: Huntington’s disease (HD) is a neurodegenerative disorder characterized by abnormal choreatic movements, subcortical dementia, and psychiatric symptoms. Psychiatric disorders encountered in HD include major depressive disorder, anxiety disorders, or isolated symptoms such as apathy or irritability in 33%276% of patients. Psychotic disorders affect 3%211% of patients. Although psychiatric symptomatology often precedes motor symptoms, there is a dearth of data regarding psychiatric care in HD. The case reported here refers to a patient suffering fromHD, major depressive disorder, and psychotic symptomatology. This patient displayed a very poor tolerance to clozapine treatment and differential results with electroconvulsivotherapy (ECT) with remission of major depressive disorder symptoms and a slight improvement in motor symptoms, but there was no effect on psychotic symptoms.