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69 result(s) for "Cohen, Ira L"
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The neuropathology of autism: defects of neurogenesis and neuronal migration, and dysplastic changes
Autism is characterized by a broad spectrum of clinical manifestations including qualitative impairments in social interactions and communication, and repetitive and stereotyped patterns of behavior. Abnormal acceleration of brain growth in early childhood, signs of slower growth of neurons, and minicolumn developmental abnormalities suggest multiregional alterations. The aim of this study was to detect the patterns of focal qualitative developmental defects and to identify brain regions that are prone to developmental alterations in autism. Formalin-fixed brain hemispheres of 13 autistic (4–60 years of age) and 14 age-matched control subjects were embedded in celloidin and cut into 200-μm-thick coronal sections, which were stained with cresyl violet and used for neuropathological evaluation. Thickening of the subependymal cell layer in two brains and subependymal nodular dysplasia in one brain is indicative of active neurogenesis in two autistic children. Subcortical, periventricular, hippocampal and cerebellar heterotopias detected in the brains of four autistic subjects (31%) reflect abnormal neuronal migration. Multifocal cerebral dysplasia resulted in local distortion of the cytoarchitecture of the neocortex in four brains (31%), of the entorhinal cortex in two brains (15%), of the cornu Ammonis in four brains and of the dentate gyrus in two brains. Cerebellar flocculonodular dysplasia detected in six subjects (46%), focal dysplasia in the vermis in one case, and hypoplasia in one subject indicate local failure of cerebellar development in 62% of autistic subjects. Detection of flocculonodular dysplasia in only one control subject and of a broad spectrum of focal qualitative neuropathological developmental changes in 12 of 13 examined brains of autistic subjects (92%) reflects multiregional dysregulation of neurogenesis, neuronal migration and maturation in autism, which may contribute to the heterogeneity of the clinical phenotype.
Abnormal Intracellular Accumulation and Extracellular Aβ Deposition in Idiopathic and Dup15q11.2-q13 Autism Spectrum Disorders
It has been shown that amyloid ß (Aβ), a product of proteolytic cleavage of the amyloid β precursor protein (APP), accumulates in neuronal cytoplasm in non-affected individuals in a cell type-specific amount. In the present study, we found that the percentage of amyloid-positive neurons increases in subjects diagnosed with idiopathic autism and subjects diagnosed with duplication 15q11.2-q13 (dup15) and autism spectrum disorder (ASD). In spite of interindividual differences within each examined group, levels of intraneuronal Aβ load were significantly greater in the dup(15) autism group than in either the control or the idiopathic autism group in 11 of 12 examined regions (p<0.0001 for all comparisons; Kruskall-Wallis test). In eight regions, intraneuronal Aβ load differed significantly between idiopathic autism and control groups (p<0.0001). The intraneuronal Aβ was mainly N-terminally truncated. Increased intraneuronal accumulation of Aβ(17-40/42) in children and adults suggests a life-long enhancement of APP processing with α-secretase in autistic subjects. Aβ accumulation in neuronal endosomes, autophagic vacuoles, Lamp1-positive lysosomes and lipofuscin, as revealed by confocal microscopy, indicates that products of enhanced α-secretase processing accumulate in organelles involved in proteolysis and storage of metabolic remnants. Diffuse plaques containing Aβ(1-40/42) detected in three subjects with ASD, 39 to 52 years of age, suggest that there is an age-associated risk of alterations of APP processing with an intraneuronal accumulation of a short form of Aβ and an extracellular deposition of full-length Aβ in nonfibrillar plaques. The higher prevalence of excessive Aβ accumulation in neurons in individuals with early onset of intractable seizures, and with a high risk of sudden unexpected death in epilepsy in autistic subjects with dup(15) compared to subjects with idiopathic ASD, supports the concept of mechanistic and functional links between autism, epilepsy and alterations of APP processing leading to neuronal and astrocytic Aβ accumulation and diffuse plaque formation.
DRD2 and PPP1R1B (DARPP-32) polymorphisms independently confer increased risk for autism spectrum disorders and additively predict affected status in male-only affected sib-pair families
Background The neurotransmitter dopamine (DA) modulates executive functions, learning, and emotional processing, all of which are impaired in individuals with autism spectrum disorders (ASDs). Our previous findings suggest a role for dopamine-related genes in families with only affected males. Methods We examined two additional genes which affect DA function, the DRD2 and PPP1R1B ( DARPP-32 ) genes, in a cohort of 112 male-only affected sib-pair families. Selected polymorphisms spanning these genes were genotyped and both family-based and population-based tests were carried out for association analysis. General discriminant analysis was used to examine the gene-gene interactions in predicting autism susceptibility. Results There was a significantly increased frequency of the DRD2 rs1800498TT genotype ( P  = 0.007) in affected males compared to the comparison group, apparently due to over-transmission of the T allele ( P  = 0.0003). The frequency of the PPP1R1B rs1495099CC genotype in affected males was also higher than that in the comparison group ( P  = 0.002) due to preferential transmission of the C allele from parents to affected children ( P  = 0.0009). Alleles rs1800498T and rs1495099C were associated with more severe problems in social interaction ( P  = 0.0002 and P  = 0.0016, respectively) and communication ( P  = 0.0004 and P  = 0.0046), and increased stereotypic behaviours ( P  = 0.0021 and P  = 0.00072). General discriminant analysis found that the DRD2 and PPP1R1B genes additively predicted ASDs ( P  = 0.00011; Canonical R = 0.26) and explain ~7% of the variance in our families. All findings remained significant following corrections for multiple testing. Conclusion Our findings support a role for the DRD2 and PPP1R1B genes in conferring risk for autism in families with only affected males and show an additive effect of these genes towards prediction of affected status in our families.
Triggers of Aggressive Behaviors in Intellectually Disabled Adults and Their Association with Autism, Medical Conditions, Psychiatric Disorders, Age and Sex: A Large-Scale Study
Aggressive behaviors in those with intellectual disability (ID) and autism (ASD) have been linked to a variety of factors including ID level, age, sex, psychiatric disorders, and medical conditions but these factors have not been studied, in large samples, in terms of how they affect the stimuli that trigger aggression. In this survey of 2243 adults, four triggers of aggression associated with frustration, discomfort, change in the physical/social environment, and defensive reactions were analyzed for their relation to ID level, ASD, age, sex, number of psychiatric diagnoses, sleeping problems, seizures, visual impairment, ear infections and gastrointestinal problems. All four triggers were associated with increasing number of psychiatric disorders, with frustration, discomfort, and change intolerance commonly linked to sleeping problems and ASD. Implications for assessment and intervention are discussed.
The DLX1and DLX2 genes and susceptibility to autism spectrum disorders
An imbalance between excitation and inhibition in the cerebral cortex has been suggested as a possible etiology of autism. The DLX genes encode homeodomain-containing transcription factors controlling the generation of GABAergic cortical interneurons. The DLX1 and DLX2 genes lie head-to-head in 2q32, a region associated with autism susceptibility. We investigated 6 Tag SNPs within the DLX1/2 genes in two cohorts of multiplex (MPX) and one of simplex (SPX) families for association with autism. Family-based association tests showed strong association with five of the SNPs. The common alleles of rs743605 and rs4519482 were significantly associated with autism ( P <0.012) in the first sample of 138 MPX families, with the latter remaining significant after correction for multiple testing ( P cor =0.0046). Findings in a second sample of 169 MPX families not only confirmed the association at rs4519482 ( P =0.034) but also showed strong allelic association of the common alleles at rs788172 , rs788173 and rs813720 ( P cor =0.0003–0.04). In the combined MPX families, the common alleles were all significantly associated with autism ( P cor =0.0005–0.016). The GGGTG haplotype was over transmitted in the two MPX cohorts and the combined samples [ P cor <0.05: P cor =0.00007 for the combined MPX families, Odds Ratio: 1.75 (95% CI: 1.33–2.30)]. Further testing in 306 SPX families replicated the association at rs4519482 ( P =0.033) and the over transmission of the haplotype GGGTG ( P =0.012) although P -values were not significant after correction for multiple testing. The findings support the presence of two functional polymorphisms, one in or near each of the DLX genes that increase susceptibility to, or cause, autism in MPX families where there is a greater genetic component for these conditions.
Autism Spectrum Disorder Decision Tree Subgroups Predict Adaptive Behavior and Autism Severity Trajectories in Children with ASD
A recent cross-sectional analysis of PDD Behavior Inventory (PDDBI) data, analyzed with a classification and regression tree algorithm, yielded a decision tree (the Autism Spectrum Disorder-Decision Tree or ASD-DT) that detected three behaviorally distinct ASD subgroups: minimally verbal, verbal, and atypical. These subgroups differed in PDDBI profiles and in factors previously reported to be predictors of autism severity and adaptive behavior trajectories. We retrospectively analyzed trajectories of adaptive skills and autism severity in these subgroups, defined by ASD-DTs calculated from initial evaluation PDDBIs. Results confirmed predictions that each subgroup had distinct trajectories that varied with the type of adaptive behavior assessed suggesting that the ASD-DT has prognostic value that could be helpful for both clinical and research applications.
Prevalence of Psychotropic Drug Use in Adults with Intellectual Disability: Positive and Negative Findings from a Large Scale Study
The use of psychotropics by categories and the reason for their prescription was investigated in a large scale study of 4,069 adults with ID, including those with autism spectrum disorder, in New York State. Similar to other studies it was found that 58 % (2,361/4,069) received one or more psychotropics. Six percent received typical, 6 % received typical, while 39 % received atypical antipsychotics. There was greater use of antidepressants (23 %), mood stabilizers (19 %), and antianxiety agents (16 %) relative to other studies. The use of anti-impulsives, stimulants and hypnotics was rare (1–2 %). Half of the psychotropics were prescribed for treatment of major psychiatric disorders, 13 % for control of challenging behaviors, and 38 % for both. Results indicated that the major psychiatric disorders, except anxiety disorder and autism, influenced the use of psychotropics and the number of medication used. These findings imply that although practitioners still rely too heavily on the use of antipsychotics in this population, there is a welcome shift in the prescription patterns relative to other studies. The practitioners appeared to use psychotropics primarily to treat diagnosed psychiatric disorders and not just to control aggressive behavior which suggests that evidence-based practice of psychiatry is playing an increasing role in the ID population.
Transgenerational Effects and Heritability of Folate Receptor Alpha Autoantibodies in Autism Spectrum Disorder
Autism Spectrum Disorder (ASD) affects an estimated prevalence of 1 in 31 children but the cause in most cases is unknown. Human and animal studies have linked ASD to Folate Receptor Alpha Autoantibodies (FRAAs). Our previous studies demonstrated that FRAAs are more common, on average, in families with children with ASD. This study reanalyzed data from a previous study which included 82 children diagnosed with ASD, 53 unaffected siblings, 70 mothers, 65 fathers, and 52 typically developing controls who did not have a history of ASD in their family. This study investigates the association of FRAA titers with ASD risk factors and explores the relationship of FRAA titers across generations. Several known risk factors for ASD, including multiplex ASD families, multiple birth pregnancies, and increased maternal and paternal ages at birth, were related to offspring FRAA titers. Multiplex ASD families demonstrated higher FRAA titers. Significant correlation were found between maternal and offspring blocking FRAA titers. FRAA titers increased across generations, although the increase in blocking FRAA titers was only seen in multiplex families. The proband with ASD showed higher blocking but not higher binding, FRAA titers compared to their non-affected siblings. Paternal FRAA titers are associated with several measures of offspring behavior and cognitive development. This research highlights the potential transgenerational transmission of FRAAs and their role in ASD. This supports the notion that heritable non-genetic factors may be important in the etiology of ASD and that FRAAs may demonstrate anticipation (worsening across generations), especially in multiplex families. FRAAs may provide one example of the possibility that susceptibility to autoimmune processes may contribute to disrupted brain development and function in ASD.
Maternal Recurrent Mood Disorders and High-Functioning Autism
A quantitative examination was made of the association of parental mood and anxiety disorders with severity of disability within a large sample of young children with Pervasive Developmental Disorder (PDD). Maternal recurrent mood disorders were associated with elevated cognitive and adaptive functioning in their affected children, parent reports of increased behavior problems and teacher reports of an internalizing behavioral style. Maternal histories of anxiety disorders and paternal depression or anxiety disorders were not associated with levels of adaptive/cognitive functioning or levels of maladaptive behaviors in the children. Various genetic models are discussed. It is hypothesized that genes associated with recurrent depression in women may exert a \"protective\" effect on cognition and adaptive functioning in children with PDD.
Mutations of the X-linked genes encoding neuroligins NLGN3 and NLGN4 are associated with autism
Many studies have supported a genetic etiology for autism. Here we report mutations in two X-linked genes encoding neuroligins NLGN3 and NLGN4 in siblings with autism-spectrum disorders. These mutations affect cell-adhesion molecules localized at the synapse and suggest that a defect of synaptogenesis may predispose to autism.