Occurrence Of Autism Spectrum Disorders Research Articles

Lien entre trouble du spectre autistique de l’enfant et anticorps antiphospholipides : une étude cas–témoin

To evaluate the association between the presence of antiphospholipid (APL) antibodies and the occurrence of autism spectrum disorder (ASD) in childhood. A prospective, monocentric case-control study from February 2012 to August 2014 comparing the APL antibodies of children with ASD (group 1) and children without ASD (group 2). Group 1 consisted of 44 children with ASD defined by clinical, genetic, metabolic, and morphological criteria. Group 2 consisted of 26 control children without ASD. One of children with ASD (2.3 %) had persistent anticardiolipin (ACL) antibodies, five of them (11.4 %) had persistent APL antibodies, one of them (2.3 %) had antiannexin V (AAV) antibodies, and two of them (4.5 %) had antiphosphatidylethanolamine (APE) antibodies. Two of the control children (7.7 %) had persistent APL antibodies. None of them had persistent ACL, AAV, or APE antibodies. Comparing group 1 and 2 children, no significant difference was found between the presence and the titers of conventional and non conventional antibodies (P<0.05). Furthermore, one mother of an autistic child (3 %) had persistent APL antibodies. ASD had no significant relation with the presence of APL antibodies.

CSF N‐glycan profile reveals sialylation deficiency in a patient with GM2 gangliosidosis presenting as childhood disintegrative disorder

Protein N-glycosylation consists in the synthesis and processing of the oligosaccharide moiety (N-glycan) linked to a protein and it serves several functions for the proper central nervous system (CNS) development and function. Previous experimental and clinical studies have shown the importance of proper glycoprotein sialylation for the synaptic function and the occurrence of autism spectrum disorders (ASD) in the presence of sialylation deficiency in the CNS. Late-onset Tay Sachs disease (LOTSD) is a lysosomal disorder caused by mutations in the HEXA gene resulting in GM2-ganglioside storage in the CNS. It is characterized by progressive neurological impairment and high co-occurrence of psychiatric disturbances. We studied the N-glycome profile of the cerebrospinal fluid (CSF) in a 14 year-old patient with GM2-gangliosidosis (LOTSD). At the age of 4, the patient presented regressive autism fulfilling criteria for childhood disintegrative disorder (CDD). A CSF sample was obtained in the course of diagnostic work-up for the suspicion of an underlying neurodegenerative disorder. We found definite changes of CSF N-glycans due to a dramatic decrease of sialylated biantennary and triantennary structures and an increase of asialo-core fucosylated bisected N-glycans. No changes of total plasma N-glycans were found. Herein findings highlight possible relationships between the early onset psychiatric disturbance featuring CDD in the patient and defective protein sialylation in the CNS. In conclusion, the study first shows aberrant N-glycan structures of CSF proteins in LOTSD; unveils possible pathomechanisms of GM2-gangliosidosis; supports existing relationships between neuropsychiatric disorders and unproper protein glycosylation in the CNS.

Functional connectivity in tuberous sclerosis complex with autistic spectrum disorder preliminary findings

Despite the frequent occurrence of autism spectrum disorder (ASD) in tuberous sclerosis complex (TSC), the neu- rophysiological factors that distinguish children with TSC from children with TSC presenting with ASD symptoms remain unspecified. Growing evidence suggests that ASD may be characterized by atypical structural and functional connectivity be- tween specific cortical regions. In this exploratory study, we utilized magnetoencephalography to derive resting brain connec- tivity patterns, in an attempt to identify neurophysiological markers that may differentiate TSC children with ASD (n = 2) from TSC children without ASD (n = 2) and typically developing children (n = 2). Connectivity pattern analysis revealed that TSC children presenting with ASD symptoms can be distinguished from TSC and typically developing children by the presence of long-range, medial, anterior-posterior connections previously observed in adolescents with ASD. While preliminary in nature, our findings support the notion that altered functional connectivity may be a constituent characteristic of ASD and may enable prediction of which TSC children are likely to develop ASD and facilitate early behavioral and medical intervention.

Synaptic proteins and receptors defects in autism spectrum disorders.

Recent studies have found that hundreds of genetic variants, including common and rare variants, rare and de novo mutations, and common polymorphisms contribute to the occurrence of autism spectrum disorders (ASDs). The mutations in a number of genes such as neurexin, neuroligin, postsynaptic density protein 95, SH3, and multiple ankyrin repeat domains 3 (SHANK3), synapsin, gephyrin, cadherin, and protocadherin, thousand-and-one-amino acid 2 kinase, and contactin, have been shown to play important roles in the development and function of synapses. In addition, synaptic receptors, such as gamma-aminobutyric acid receptors and glutamate receptors, have also been associated with ASDs. This review will primarily focus on the defects of synaptic proteins and receptors associated with ASDs and their roles in the pathogenesis of ASDs via synaptic pathways.

Research round-up

Research round-up

Autism spectrum disorders in XYY syndrome: two new cases and systematic review of the literature

Abnormalities of the sex chromosomes (47, XXY, 47 XYY, 45,X/46,XY mosaicism) are frequently associated with Autism Spectrum Disorders (ASD), but the male predisposition to these disorders has not been clearly explained. Previously, the role of the X chromosome was considered important in the ASD mainly because autistic symptoms were detected in genetic syndromes involving X chromosome (fragile X syndrome, Rett syndrome, Klinefelter syndrome). Instead, few studies have analyzed the possible role of the Y chromosome in the ASD. This study explores the role of the Y chromosome in ASD through a systematic literature review about the association between ASD and XYY syndrome and a description of two new cases with this association. The literature review considered studies published in peer-reviewed journals, included in the MEDLINE and PubMed databases, that examined the association between ASD and XYY syndrome. Few studies reported the occurrence of ASD in children with XYY karyotype and the majority of them did not reported a well-defined autism diagnostic category associated with an extra Y chromosome, but several clinical conditions that are generically described as language and social impairment. This study underlines the underestimated role of the Y chromosome in ASD, and we postulate that all the ASD associated with the XYY karyotype may presumably fall within mild degree of ASD as in our cases.

To what extent do environmental factors contribute to the occurrence of autism spectrum disorders?

To what extent do environmental factors contribute to the occurrence of autism spectrum disorders?

The identification and measurement of autistic features in children with septo-optic dysplasia, optic nerve hypoplasia and isolated hypopituitarism

This study aimed to highlight the occurrence of autism spectrum disorders (ASDs) in children with septo-optic dysplasia (SOD) and optic nerve hypoplasia (ONH). A cross-sectional study was designed, including 28 children with SOD and 14 children with ONH. Clinician diagnosis of ASD was reported in 14 children. The Social Communication Questionnaire (SCQ) reported that 23 children met the cut-off point for ASD, and 9 children met the cut-off point for autism. Greater levels of intellectual disability and visual loss were reported in children with ASD in comparison to those without ASD, but, of the two, intellectual disability was a better predictor for ASD. The SCQ lost its sensitivity and specificity in children who had greater visual loss which highlights a requirement for a measure that is sensitive to visual loss. It is also recommended that children with SOD/ONH would benefit from routine screening for ASDs.

Examining the Comorbidity of Bipolar Disorder and Autism Spectrum Disorders

Although mood dysregulation is frequently associated with autism spectrum disorders (ASD) and autistic traits are common in youth with bipolar disorder, uncertainties remain regarding the comorbid occurrence of bipolar disorder and ASD. This study examines the clinical and familial correlates of bipolar disorder when it occurs with and without ASD comorbidity in a well-characterized, research-referred population of youth with bipolar disorder. We hypothesized that in youth with bipolar disorder, the clinical and familial correlates of bipolar disorder will be comparable irrespective of the comorbidity with ASD. Clinical correlates and familial risk were assessed by secondary analysis of the data from a large family study of youth with bipolar I disorder (diagnosis based on DSM-IV criteria; probands n = 157, relatives n = 487; study period: November 1997-September 2002). Findings in bipolar I youth were compared with those in youth with attention-deficit/hyperactivity disorder (diagnosis based on DSM-III-R criteria) without bipolar I disorder (probands n = 162, relatives n = 511) and age- and sex-matched controls without bipolar I disorder or attention-deficit/hyperactivity disorder (probands n = 136, relatives n = 411). All subjects were comprehensively assessed using structured diagnostic interviews and a wide range of nonoverlapping measures assessing multiple dimensions of functioning. Thirty percent (47/155) of the bipolar I probands met criteria for ASD (diagnosis based on DSM-III-R criteria). The mean ± SD age at onset of bipolar I disorder was significantly earlier in the presence of ASD comorbidity (4.7 ± 2.9 vs 6.3 ± 3.7 years; P = .01). The phenotypic and familial correlates of bipolar disorder were similar in youth with and without ASD comorbidity. A clinically significant minority of youth with bipolar I disorder suffers from comorbid ASD. Phenotypic and familial correlates of bipolar disorder were typical of the disorder in the presence of ASD comorbidity. Bipolar I disorder comorbidity with ASD represents a very severe psychopathologic state in youth.

Association of gestational diabetes mellitus with occurrence of Autism: A Cohort Study

BackgroundSeveral antenatal and perinatal adverse events have been reported to be potentially associated with increased risk of occurrence of autism spectrum disorder (ASD). Among these is the gestational diabetes mellitus (GDM).ObjectivesTo evaluate the potential association between GDM and ASD.MethodsA retrospective cohort study has been nested on a community trial titled as “Delaying the Development of Diabetes Mellitus type 2 (AMAL study)” in Oman. The study population included 532 women with a total of 3,196 pregnancies. Multi‐variate Cox proportional hazard regression analyses were conducted to explorer the association between GDM and ASD, adjusting for important confounders. The main outcome measure was hazard ratio (HR) of the effect of GDM on ASD.ResultsA total of 42 ASD cases have been enumerated over 3714 person‐years of follow up. In the crude model, pregnancies complicated with GDM carried a higher risk of ASD children than pregnancies without GDM (HR = 2.3; 95% CI = 1.5, 3.4). the adjusted model, the association persisted even with control of the confounding effect of maternal age (HR = 1.71; 95% CI = 1.1, 2.3).ConclusionThis study provides a supportive evidence that GDM may carry an increased risk of occurrence of ASD. It calls for more strict control of GDm, especially that diabetes mellitus and obesity have reached alarming epidemiologic rates in Oman and the region.

Association of the Catechol-o-Methyltransferase Gene Polymorphisms with Korean Autism Spectrum Disorders

This study evaluated the family-based genetic association between autism spectrum disorders (ASDs) and 5 single-nucleotide polymorphisms (SNPs) in the catechol-o-methyltransferase gene (COMT), which was found among 151 Korean ASDs family trios (dominant model Z = 2.598, P = 0.009, PFDR = 0.045). We found a statistically significant allele transmission or association in terms of the rs6269 SNP in the ASDs trios. Moreover, in the haplotype analysis, the haplotypes with rs6269 demonstrated significant evidence of an association with ASDs (additive model rs6269-rs4818-rs4680-rs769224 haplotype P = 0.004, PFDR = 0.040). Thus, an association may exist between the variants of the COMT gene and the occurrence of ASDs in Koreans.

Autism spectrum disorders (ASD) in Africa: a perspective

The universal occurrence of autism spectrum disorders (ASD) was queried about twenty-six years ago. It was thought to occur only in western industrialized countries with high technological development. Over the last decade, knowledge about ASD and its prevalence has been documented as being on the rise in different regions of the world, with most literature coming from the western world -- the situation in Africa on aspects of ASD remain unclear. Literature cited in Pubmed over the last decade on aspects of epidemiology, diagnosis, aetiology and knowledge of ASD in the African context were assessed. autism, diagnosis, aetiology, knowledge and Africa were variously combined in the literature search. No study specifically addressed the epidemiology of ASD in Africa. One of the two studies that were relevant addressed epidemiology of ASD in Arab countries, though included two Northern African countries. A higher proportion of non-verbal cases of ASD compared to verbal cases was documented in literature coming from Africa. Associated co-morbid disorders included intellectual disability, epilepsy and oculo-cutaneous albinism. Aetiological factors postulated included post-encephalitic infection, genetic and auto-immune factors, and vitamin D deficiency. Knowledge about ASD in Africa was noted to be low. There is a need for epidemiological studies in Africa to define the magnitude of the problem of ASD and the characteristics of children affected by ASD in this region. This would help in planning and might be helpful in answering the question of aetiology of ASD. Policy making needs to be directed at issues of childhood developmental disorders in Africa.

Autism spectrum disorders: Toward a gendered embodiment model

One of the most consistent observations in the epidemiology of autism spectrum disorders (ASD) is the preponderance of male cases. A few hypotheses have been put forth which attempt to explain this divergence in terms of sex-linked biology, with limited success. Feminist epidemiologists suggest the importance of investigating specific mechanisms for male-female differences in health outcomes, which may include sex-linked biology and/or gender relations, as well as complex biosocial interactions. Neither domain has been systematically investigated for autism, and the possible role of gender has been particularly neglected. In this article, we posit hypotheses about how social processes based on perception of persons as male or female, particularly patterns of social and physical interaction in early development, may affect the observed occurrence and diagnosis of ASD. We gesture toward an embodiment model, incorporating hypotheses about initial biological vulnerabilities to autism – which may or may not be differentially distributed in relation to sex biology – and their interactions with gender relations, which are demonstrably different for male and female infants. Toward building such a model, we first review the epidemiology of ASD with an eye toward male-female differences, then present a theory of gender as a “pervasive developmental environment” with relevance for the excess burden of autism among males. Finally, we suggest research strategies to further investigate this issue.

Autism spectrum disorders

Pervasive developmental disorders are a group of neurodevelopmental disorders characterized by impairments in communication, reciprocal social interaction and restricted repetitive behaviors or interests. The term autism spectrum disorders (ASD) has been used to describe their variable presentation. Although the cause of these disorders is not yet known, studies strongly suggest a genetic basis with a complex mode of inheritance. More research is needed to explore environmental factors that could be contributing to the cause of these disorders. The occurrence of ASD has been increasing worldwide, with the most recent prevalence studies indicating that they are present in 6 per 1000 children. The objectives of this article are to provide physicians with relevant information needed to identify and refer children presenting with symptoms suggestive of ASDs to specialized centers early, and to make them feel comfortable in dealing with public concerns regarding controversial issues about the etiology and management of these disorders.

Epigenetics of autism spectrum disorders

The autism spectrum disorders (ASD) comprise a complex group of behaviorally related disorders that are primarily genetic in origin. Involvement of epigenetic regulatory mechanisms in the pathogenesis of ASD has been suggested by the occurrence of ASD in patients with disorders arising from epigenetic mutations (fragile X syndrome) or that involve key epigenetic regulatory factors (Rett syndrome). Moreover, the most common recurrent cytogenetic abnormalities in ASD involve maternally derived duplications of the imprinted domain on chromosome 15q11-13. Thus, parent of origin effects on sharing and linkage to imprinted regions on chromosomes 15q and 7q suggest that these regions warrant specific examination from an epigenetic perspective, particularly because epigenetic modifications do not change the primary genomic sequence, allowing risk epialleles to evade detection using standard screening strategies. This review examines the potential role of epigenetic factors in the etiology of ASD.

No effect of MMR withdrawal on the incidence of autism: a total population study

A causal relationship between the measles, mumps, and rubella (MMR) vaccine and occurrence of autism spectrum disorders (ASD) has been claimed, based on an increase in ASD in the USA and the UK after introduction of the MMR vaccine. However, the possibility that this increase is coincidental has not been eliminated. The unique circumstances of a Japanese MMR vaccination program provide an opportunity for comparison of ASD incidence before and after termination of the program. This study examined cumulative incidence of ASD up to age seven for children born from 1988 to 1996 in Kohoku Ward (population approximately 300,000), Yokohama, Japan. ASD cases included all cases of pervasive developmental disorders according to ICD-10 guidelines. The MMR vaccination rate in the city of Yokohama declined significantly in the birth cohorts of years 1988 through 1992, and not a single vaccination was administered in 1993 or thereafter. In contrast, cumulative incidence of ASD up to age seven increased significantly in the birth cohorts of years 1988 through 1996 and most notably rose dramatically beginning with the birth cohort of 1993. The significance of this finding is that MMR vaccination is most unlikely to be a main cause of ASD, that it cannot explain the rise over time in the incidence of ASD, and that withdrawal of MMR in countries where it is still being used cannot be expected to lead to a reduction in the incidence of ASD.

IGF-I and steroid hormone profile in the follicular fluid of sows treated with acth prior to follicle selection

Available evidence implicates environmental factors in the pathogenesis of autism spectrum disorders (ASD). However, the role of specific environmental chemicals such as phthalate esters that influence ASD risk remains elusive. This paper systematically reviews published evidences on association between prenatal and/or childhood exposure to phthalate and ASD.Studies pertaining to systematic literature search from Scopus, PubMed, PsycInfo and Web of Science prior to December 2015 were identified. The authors included studies which assessed the effect of exposure to phthalates on occurrence of ASD. This comprehensive bibliographic search identified five independent studies. Each eligible paper was summarized with respect to its methods and results with particular attention to study design and exposure assessment. Because of the heterogeneity in the type of included studies, different methods of assessing exposure to phthalates and the use of different statistics for summarizing the results, meta-analysis could not be used to combine the results of included studies.The results of this systematic review have revealed the limited number of studies conducted and assessed phthalate exposure. Seven studies were regarded as relevant to the objectives of this review. Two of them did not measure phthalate exposure directly and did not result in quantitative results. Out of the five studies in which phthalate exposure was mainly measured by the examining biomarkers in biological samples, two were cohort studies (one with positive results and another one with not clear association). Among the three case control studies, two of them showed a significant relation between exposure to phthalate and ASD and the last case control study had negative results. Indeed, this case control studies showed a compromised phthalate metabolite glucuronidation pathway, as a probable explanation of mechanism of the relation between phthalate exposure and ASD.This review reveals evidence showing a connection between exposure to phthalates and ASD. Nevertheless, further research is needed with appropriate attention to exposure assessment and relevant pre and post-natal cofounders.