1. {{Periconceptual folate and autism}}. {BMJ};2013;346:f900.
2. Ahmed MM, Heckman WW, Dailey SH. {{Type IIB Thyroplasty for Phonic Tics in a Pediatric Patient With Autism Spectrum Disorder: A Case Report}}. {J Voice};2013 (Feb 11)
OBJECTIVES/HYPOTHESIS: Autism spectrum disorders (ASDs) are commonly associated with Tourette syndrome (TS). TS is classically associated with tic production. A tic is defined as sudden, brief, involuntary production of movement (motor tics) or sound (phonic tics). STUDY DESIGN: Case report. METHODS: We present a case report of a 14-year-old boy with ASD and vocal tics. Vocal tic frequency was nearly 2000 per day and 90dB in volume. He presented to our laryngology clinic after multiple failed attempts of pharmacologic management of vocal fold botulinum toxin injection. After evaluation in our clinic, we recommended a lateralization (type IIB) thyroplasty. An autologous cartilage graft from the superior thyroid ala was used and held in place with a bioresorbable mesh. Using 4-0 prolene sutures, the mesh was secured in place. The operation was well tolerated with minimal signs of aspiration, and he was discharged to his home within 48 hours. RESULTS: Six months postoperatively, there was 90% reduction in tic frequency and 50% reduction in intensity. Additionally, he has shown improved ability to converse with his peers, participate in school activities, and even has improved nutritional status. CONCLUSIONS: Alteration of laryngeal geometry could serve as an effective site of intervention for intractable phonic tics. Reduction of phonic tic frequency and intensity may also stimulate language development in patients ASD. We also demonstrate additional use of bioresorbable plates in pediatric laryngeal framework surgery. Additional neurophysiologic studies are needed to explore the mechanism by which midline lateralization thyroplasty influences phonic tic generation.
Lien vers le texte intégral (Open Access ou abonnement)
3. Das DK, Raha S, Sanghavi D, Maitra A, Udani V. {{Spectrum of MECP2 gene mutations in a cohort of Indian patients with Rett syndrome: Report of two novel mutations}}. {Gene};2013 (Feb 15);515(1):78-83.
Rett syndrome (RTT) is an X-linked neurodevelopmental disorder, primarily affecting females and characterized by developmental regression, epilepsy, stereotypical hand movements, and motor abnormalities. Its prevalence is about 1 in 10,000 female births. Rett syndrome is caused by mutations within methyl CpG-binding protein 2 (MECP2) gene. Over 270 individual nucleotide changes which cause pathogenic mutations have been reported. However, eight most commonly occurring missense and nonsense mutations account for almost 70% of all patients. We screened 90 individuals with Rett syndrome phenotype. A total of 19 different MECP2 mutations and polymorphisms were identified in 27 patients. Of the 19 mutations, we identified 7 (37%) frameshift, 6 (31%) nonsense, 14 (74%) missense mutations and one duplication (5%). The most frequent pathogenic changes were: missense p.T158M (11%), p.R133C (7.4%), and p.R306C (7.4%) and nonsense p.R168X (11%), p.R255X (7.4%) mutations. We have identified two novel mutations namely p.385-388delPLPP present in atypical patients and p.Glu290AlafsX38 present in a classical patient of Rett syndrome. Sequence homology for p.385-388delPLPP mutation revealed that these 4 amino acids were conserved across mammalian species. This indicated the importance of these 4 amino acids in structure and function of the protein. A novel variant p.T479T has also been identified in a patient with atypical Rett syndrome. A total of 62 (69%) patients remained without molecular genetics diagnosis that necessitates further search for mutations in other genes like CDKL5 and FOXG1 that are known to cause Rett phenotype. The majority of mutations are detected in exon 4 and only one mutation was present in exon 3. Therefore, our study suggests the need for screening exon 4 of MECP2 as first line of diagnosis in these patients.
Lien vers le texte intégral (Open Access ou abonnement)
4. Dougherty JD, Maloney SE, Wozniak DF, Rieger MA, Sonnenblick L, Coppola G, Mahieu NG, Zhang J, Cai J, Patti GJ, Abrahams BS, Geschwind DH, Heintz N. {{The Disruption of Celf6, a Gene Identified by Translational Profiling of Serotonergic Neurons, Results in Autism-Related Behaviors}}. {J Neurosci};2013 (Feb 13);33(7):2732-2753.
The immense molecular diversity of neurons challenges our ability to understand the genetic and cellular etiology of neuropsychiatric disorders. Leveraging knowledge from neurobiology may help parse the genetic complexity: identifying genes important for a circuit that mediates a particular symptom of a disease may help identify polymorphisms that contribute to risk for the disease as a whole. The serotonergic system has long been suspected in disorders that have symptoms of repetitive behaviors and resistance to change, including autism. We generated a bacTRAP mouse line to permit translational profiling of serotonergic neurons. From this, we identified several thousand serotonergic-cell expressed transcripts, of which 174 were highly enriched, including all known markers of these cells. Analysis of common variants near the corresponding genes in the AGRE collection implicated the RNA binding protein CELF6 in autism risk. Screening for rare variants in CELF6 identified an inherited premature stop codon in one of the probands. Subsequent disruption of Celf6 in mice resulted in animals exhibiting resistance to change and decreased ultrasonic vocalization as well as abnormal levels of serotonin in the brain. This work provides a reproducible and accurate method to profile serotonergic neurons under a variety of conditions and suggests a novel paradigm for gaining information on the etiology of psychiatric disorders.
Lien vers le texte intégral (Open Access ou abonnement)
5. Gareau C, Houssin E, Martel D, Coudert L, Mellaoui S, Huot ME, Laprise P, Mazroui R. {{Characterization of fragile x mental retardation protein recruitment and dynamics in Drosophila stress granules}}. {PLoS One};2013;8(2):e55342.
The RNA-binding protein Fragile X Mental Retardation (FMRP) is an evolutionarily conserved protein that is particularly abundant in the brain due to its high expression in neurons. FMRP deficiency causes fragile X mental retardation syndrome. In neurons, FMRP controls the translation of target mRNAs in part by promoting dynamic transport in and out neuronal RNA granules. We and others have previously shown that upon stress, mammalian FMRP dissociates from translating polysomes to localize into neuronal-like granules termed stress granules (SG). This localization of FMRP in SG is conserved in Drosophila. Whether FMRP plays a key role in SG formation, how FMRP is recruited into SG, and whether its association with SG is dynamic are currently unknown. In contrast with mammalian FMRP, which has two paralog proteins, Drosophila FMR1 (dFMRP) is encoded by a single gene that has no paralog. Using this genetically simple model, we assessed the role of dFMRP in SG formation and defined the determinants required for its recruitment in SG as well as its dynamics in SG. We show that dFMRP is dispensable for SG formation in vitro and ex vivo. FRAP experiments showed that dFMRP shuttles in and out SG. The shuttling activity of dFMRP is mediated by a protein-protein interaction domain located at the N-terminus of the protein. This domain is, however, dispensable for the localization of dFMRP in SG. This localization of dFMRP in SG requires the KH and RGG motifs which are known to mediate RNA binding, as well as the C-terminal glutamine/asparagine rich domain. Our studies thus suggest that the mechanisms controlling the recruitment of FMRP into SG and those that promote its shuttling between granules and the cytosol are uncoupled. To our knowledge, this is the first demonstration of the regulated shuttling activity of a SG component between RNA granules and the cytosol.
Lien vers le texte intégral (Open Access ou abonnement)
6. Kumar B, Prakash A, Sewal RK, Medhi B, Modi M. {{Drug therapy in autism: a present and future perspective}}. {Pharmacol Rep};2012 (Nov);64(6):1291-1304.
Autism is a neurodevelopmental disorder, with a multifactorial etiology, characterized by severe abnormalities in communications, social awareness and skills, and the presence of restrictive and stereotyped patterns of behaviors. It is traditionally considered a « static » encephalopathic disorder without any specific cure and few effective biomedical interventions. There are various factors which are involved in the etiopathogenesis of autism or autism spectrum disorder (ASD) such as impaired immune responses, neuroinflammation, abnormal neurotransmission, oxidative stress, mitochondrial dysfunction, environmental toxins and stressors. The autism is often associated with a number of genetic disorders such as fragile X syndrome, tuberous sclerosis, epilepsy and Down syndrome. The recent approaches to autism treatment included various non-pharmacological and pharmacological therapy such as food supplementation, detoxification, treatment of neuroinflammation, immunologic treatments and psychotropic medications, which are found to be effective in treating various behavioral symptoms of autism. In current practice, there is no curative treatment for autism but the recommended treatment for autism involves educational therapies: speech therapy, sensory integration therapy, auditory therapy. There are classes of different pharmacological agents which are found to be effective in improving behavioral symptoms of ASD such as neurotransmitter reuptake inhibitors (fluoxetine), tricyclic antidepressants (imipramine), anticonvulsants (lamotrigine), atypical antipsychotics (clozapine), acetylcholinesterase inhibitors (rivastigmine), etc. New classes of drugs with novel mechanisms of action should be there so that this disorder will become less prevalent in the future.
7. Mohammadi MR, Zarafshan H, Ghasempour S. {{Broader Autism Phenotype in Iranian Parents of Children with Autism Spectrum Disorders vs. Normal Children}}. {Iran J Psychiatry};2012 (Fall);7(4):157-163.
OBJECTIVE: The aim of the present study was to compare the broader autism phenotype in Iranian parents of children with autism spectrum disorders and parents of typically developing children. METHOD: Parents of children with ASD and parents of typically developing children were asked to complete the Persian version of the Autism Spectrum Quotient (AQ). In the ASD group, families included 204 parents (96 fathers and 108 mothers) of children diagnosed as having autism (Autistic Disorder, or AD) (n=124), Asperger Syndrome (AS) or High Functioning Autism (HFA) (n=48) and Pervasive Developmental Disorder Not Otherwise Specified (PDD-NOS) (n=32) by psychiatrists based on the Diagnostic and Statistical Manual of Mental Disorders-4thedition (DSM-IV-TR) criteria. In the control group, 210 (108 fathers and 102 mothers) parents of typically developing children. Parents of typically developing children were selected from four primary schools. Based on family reports, their children did not have any psychiatric problems. Total AQ score and each of the 5 subscales were analyzed using two-way ANOVAs with sex and group as factors. RESULTS: The mean age of ASD fathers was 40.6 years (SD=5.96; range 31-54), and of ASD mothers was 34.7 years (SD=4.55; range 28-45). The mean age of control fathers was 37 years (SD=4.6; range 29-45) and of control mothers was 34.11 years (SD=4.86; range 28-45). Group differences were found in age (p 0/001). On total AQ, a main effect for group and sex was found. ASD parents scored higher than controls (F(1,410)=77.876, P 0/001) and males scored higher than females (F(1,410)=23.324, P 0/001). Also, Group by Sex interaction was significant (F(1,410)=4.986, P 0/05). Results of MANOVA analysis displayed significant differences between ASD’s subgroups on total AQ and subscales scores (F (15, 1121)=13.924, p < 0.0005; Wilk’s Lambda= 0.624, partial =0.145). Pairwise comparisons between ASD’s subgroups and Normal group showed that mean scores for the Asperger group are significantly more than other groups in total AQ, attention switching and communication subscales (p < 0.05). The frequencies of BAP (X^2=52.721 (DF=1), P 0/001), MAP (X^2=17.133 (DF=1), P 0/001) and NAP (X^2=12.722 (DF=1), P 0/001) in ASD parents were significantly more than control parents. The frequencies of Broader Autism Phenotype (BAP) (X^2=3.842 (DF=1), P0/05) and Medium Autism phenotype (MAP) (X^2=0.060 (DF=1), P0/05) did not significantly differ in ASD fathers and mothers, but the proportion of fathers in Narrow Autism Phenotype(NAP) range was more than mothers (X2=14.344, P 0/001). CONCLUSION: Results of the present study revealed that parents of children with ASD scored significantly higher than control parents on total AQ and its subscales and the rates of BAP, MAP and NAP were higher in ASD parents than in controls. In addition, in ASD’s subgroups, the parents of Asperger children scored significantly more than other subgroups (Autism and PDD-nos) and the normal group on total AQ and some subscales.
8. Mostafa GA, Shehab AA, Al-Ayadhi LY. {{The link between some alleles on human leukocyte antigen system and autism in children}}. {J Neuroimmunol};2013 (Feb 15);255(1-2):70-74.
The reason behind the initiation of autoimmunity to brain in some patients with autism is not well understood. There is an association between some autoimmune disorders and specific alleles of human leukocyte antigen (HLA) system. Thus, we examined the frequency of some HLA-DRB1 alleles in 100 autistic children and 100 healthy matched-children by differential hybridization with sequence-specific oligonucleotide probes. The risk of association between acquisition or absence of these alleles and autism and also a history of autoimmune diseases in autistic relatives was studied. Autistic children had significantly higher frequency of HLA-DRB1*11 allele than controls (P<0.001). In contrast, autistic children had significantly lower frequency of HLA-DRB1*03 allele than controls (P<0.001). Acquisition of HLA-DRB1*011 and absence of HLA-DRB1*3 had significant risk for association with autism (odds ratio: 3.21 and 0.17, respectively; 95% CI: 1.65-6.31 and 0.06-0.45, respectively). HLA-DRB1*11 had a significant risk for association with a family history of autoimmunity in autistic children (odds ratio: 5.67; 95% CI: 2.07-16.3). In conclusions, the link of some HLA alleles to autism and to family history of autoimmunity indicates the possible contributing role of these alleles to autoimmunity in some autistic children. Despite a relatively small sample size, we are the first to report a probable protective association of HLA-DRB1*03 allele with autism. It warrants a replication study of a larger sample to validate the HLA-DRB1 genetic association with autism. This is important to determine whether therapeutic modulations of the immune function are legitimate avenues for novel therapy in selected cases of autism.
Lien vers le texte intégral (Open Access ou abonnement)
9. Werling DM, Geschwind DH. {{Sex differences in autism spectrum disorders}}. {Curr Opin Neurol};2013 (Feb 13)
PURPOSE OF REVIEW: A strong male bias in autism spectrum disorder (ASD) prevalence has been observed with striking consistency, but no mechanism has yet to definitively account for this sex difference. This review explores the current status of epidemiological, genetic, and neuroendocrinological work addressing ASD prevalence and liability in males and females, so as to frame the major issues necessary to pursue a more complete understanding of the biological basis for sex-differential risk. RECENT FINDINGS: Recent studies continue to report a male bias in ASD prevalence, but also suggest that sex differences in phenotypic presentation, including fewer restricted and repetitive behaviors and externalizing behavioral problems in females, may contribute to this bias. Genetic studies demonstrate that females are protected from the effects of heritable and de-novo ASD risk variants, and compelling work suggests that sex chromosomal genes and/or sex hormones, especially testosterone, may modulate the effects of genetic variation on the presentation of an autistic phenotype. SUMMARY: ASDs affect females less frequently than males, and several sex-differential genetic and hormonal factors may contribute. Future work to determine the mechanisms by which these factors confer risk and protection to males and females is essential.
