Autism and Möbius sequence: an exploratory study of children in northeastern Brazil

A Role for Gene-Environment Interactions in Autism Spectrum Disorder Is Supported by Variants in Genes Regulating the Effects of Exposure to Xenobiotics

Heritability estimates support the contribution of genetics and the environment to the etiology of Autism Spectrum Disorder (ASD), but a role for gene-environment interactions is insufficiently explored. Genes involved in detoxification pathways and physiological permeability barriers (e.g., blood-brain barrier, placenta and respiratory airways), which regulate the effects of exposure to xenobiotics during early stages of neurodevelopment when the immature brain is extremely vulnerable, may be particularly relevant in this context. Our objective was to identify genes involved in the regulation of xenobiotic detoxification or the function of physiological barriers (the XenoReg genes) presenting predicted damaging variants in subjects with ASD, and to understand their interaction patterns with ubiquitous xenobiotics previously implicated in this disorder. We defined a panel of 519 XenoReg genes through literature review and database queries. Large ASD datasets were inspected for in silico predicted damaging Single Nucleotide Variants (SNVs) (N = 2,674 subjects) or Copy Number Variants (CNVs) (N = 3,570 subjects) in XenoReg genes. We queried the Comparative Toxicogenomics Database (CTD) to identify interaction pairs between XenoReg genes and xenobiotics. The interrogation of ASD datasets for variants in the XenoReg gene panel identified 77 genes with high evidence for a role in ASD, according to pre-specified prioritization criteria. These include 47 genes encoding detoxification enzymes and 30 genes encoding proteins involved in physiological barrier function, among which 15 are previous reported candidates for ASD. The CTD query revealed 397 gene-environment interaction pairs between these XenoReg genes and 80% (48/60) of the analyzed xenobiotics. The top interacting genes and xenobiotics were, respectively, CYP1A2, ABCB1, ABCG2, GSTM1, and CYP2D6 and benzo-(a)-pyrene, valproic acid, bisphenol A, particulate matter, methylmercury, and perfluorinated compounds. Individuals carrying predicted damaging variants in high evidence XenoReg genes are likely to have less efficient detoxification systems or impaired physiological barriers. They can therefore be particularly susceptible to early life exposure to ubiquitous xenobiotics, which elicit neuropathological mechanisms in the immature brain, such as epigenetic changes, oxidative stress, neuroinflammation, hypoxic damage, and endocrine disruption. As exposure to environmental factors may be mitigated for individuals with risk variants, this work provides new perspectives to personalized prevention and health management policies for ASD.

Huntingtin gene CAG repeat size affects autism risk: Family-based and case-control association study

The Huntingtin (HTT) gene contains a CAG repeat in exon 1, whose expansion beyond 39 repeats consistently leads to Huntington's disease (HD), whereas normal-to-intermediate alleles seemingly modulate brain structure, function and behavior. The role of the CAG repeat in Autism Spectrum Disorder (ASD) was investigated applying both family-based and case-control association designs, with the SCA3 repeat as a negative control. Significant overtransmission of "long" CAG alleles (≥17 repeats) to autistic children and of "short" alleles (≤16 repeats) to their unaffected siblings (all p < 10^-5 ) was observed in 612 ASD families (548 simplex and 64 multiplex). Surprisingly, both 193 population controls and 1,188 neurological non-HD controls have significantly lower frequencies of "short" CAG alleles compared to 185 unaffected siblings and higher rates of "long" alleles compared to 548 ASD patients from the same families (p < .05-.001). The SCA3 CAG repeat displays no association. "Short" HTT alleles seemingly exert a protective effect from clinically overt autism in families carrying a genetic predisposition for ASD, while "long" alleles may enhance autism risk. Differential penetrance of autism-inducing genetic/epigenetic variants may imply atypical developmental trajectories linked to HTT functions, including excitation/inhibition imbalance, cortical neurogenesis and apoptosis, neuronal migration, synapse formation, connectivity and homeostasis.

Brain phenotyping in Moebius syndrome and other congenital facial weakness disorders by diffusion MRI morphometry

In this study, we used a novel imaging technique, DTI (diffusion tensor imaging)-driven tensor-based morphometry, to investigate brain anatomy in subjects diagnosed with Moebius syndrome (n = 21), other congenital facial weakness disorders (n = 9) and healthy controls (n = 15). First, we selected a subgroup of subjects who satisfied the minimum diagnostic criteria for Moebius syndrome with only mild additional neurological findings. Compared to controls, in this cohort, we found a small region of highly significant volumetric reduction in the paramedian pontine reticular formation and the medial longitudinal fasciculus, important structures for the initiation and coordination of conjugate horizontal gaze. Subsequently, we tested if volume measurements from this region could help differentiate individual subjects of the different cohorts that were included in our study. We found that this region allowed discriminating Moebius syndrome subjects from congenital facial weakness disorders and healthy controls with high sensitivity (94%) and specificity (89%). Interestingly, this region was normal in congenital facial weakness subjects with oculomotor deficits of myopathic origin, who would have been classified as Moebius on the basis of purely clinical diagnostic criteria, indicating a potential role for diffusion MRI morphometry for differential diagnosis in this condition. When the entire Moebius syndrome cohort was compared to healthy controls, in addition to this 'landmark' region, other areas of significantly reduced volume in the brainstem emerged, including the location of the nuclei and fibres of cranial nerve VI (abducens nerve), and fibres of cranial nerve VII (facial nerve), and a more rostral portion of the medial longitudinal fasciculus. The high sensitivity and specificity of DTI-driven tensor-based morphometry in reliably detecting very small areas of volumetric abnormality found in this study suggest broader applications of this analysis in personalized medicine to detect hypoplasia or atrophy of small pathways and/or brainstem nuclei in other neurological disorders.

Impaired neurodevelopmental pathways in autism spectrum disorder: a review of signaling mechanisms and crosstalk

Background

The development of an autistic brain is a highly complex process as evident from the involvement of various genetic and non-genetic factors in the etiology of the autism spectrum disorder (ASD). Despite being a multifactorial neurodevelopmental disorder, autistic patients display a few key characteristics, such as the impaired social interactions and elevated repetitive behaviors, suggesting the perturbation of specific neuronal circuits resulted from abnormal signaling pathways during brain development in ASD. A comprehensive review for autistic signaling mechanisms and interactions may provide a better understanding of ASD etiology and treatment.

Main body

Recent studies on genetic models and ASD patients with several different mutated genes revealed the dysregulation of several key signaling pathways, such as WNT, BMP, SHH, and retinoic acid (RA) signaling. Although no direct evidence of dysfunctional FGF or TGF-β signaling in ASD has been reported so far, a few examples of indirect evidence can be found. This review article summarizes how various genetic and non-genetic factors which have been reported contributing to ASD interact with WNT, BMP/TGF-β, SHH, FGF, and RA signaling pathways. The autism-associated gene ubiquitin-protein ligase E3A (UBE3A) has been reported to influence WNT, BMP, and RA signaling pathways, suggesting crosstalk between various signaling pathways during autistic brain development. Finally, the article comments on what further studies could be performed to gain deeper insights into the understanding of perturbed signaling pathways in the etiology of ASD.

Conclusion

The understanding of mechanisms behind various signaling pathways in the etiology of ASD may help to facilitate the identification of potential therapeutic targets and design of new treatment methods.

Autism-related behaviors in the cyclooxygenase-2-deficient mouse model

Prostaglandin E2 (PGE2) is an endogenous lipid molecule involved in normal brain development. Cyclooxygenase-2 (COX2) is the main regulator of PGE2 synthesis. Emerging clinical and molecular research provides compelling evidence that abnormal COX2/PGE2 signaling is associated with autism spectrum disorder (ASD). We previously found that COX2 knockout mice had dysregulated expression of many ASD genes belonging to important biological pathways for neurodevelopment. The present study is the first to show the connection between irregular COX2/PGE2 signaling and autism-related behaviors in male and female COX2-deficient knockin, (COX)-2^- , mice at young (4-6 weeks) or adult (8-11 weeks) ages. Autism-related behaviors were prominent in male (COX)-2^- mice for most behavioral tests. In the open field test, (COX)-2^- mice traveled more than controls and adult male (COX)-2^- mice spent less time in the center indicating elevated hyperactive and anxiety-linked behaviors. (COX)-2^- mice also buried more marbles, with males burying more than females, suggesting increased anxiety and repetitive behaviors. Young male (COX)-2^- mice fell more frequently in the inverted screen test revealing motor deficits. The three-chamber sociability test found that adult female (COX)-2^- mice spent less time in the novel mouse chamber indicative of social abnormalities. In addition, male (COX)-2^- mice showed altered expression of several autism-linked genes: Wnt2, Glo1, Grm5 and Mmp9. Overall, our findings offer new insight into the involvement of disrupted COX2/PGE2 signaling in ASD pathology with age-related differences and greater impact on males. We propose that (COX)-2^- mice might serve as a novel model system to study specific types of autism.

Maternal exposure to prostaglandin E2 modifies expression of Wnt genes in mouse brain - An autism connection

Prostaglandin E₂ (PGE₂) is a lipid signaling molecule important for brain development and function. Various genetic and environmental factors can influence the level of PGE₂ and increase the risk of developing Autism Spectrum Disorder (ASD). We have previously shown that in neuronal cell lines and mouse brain, PGE₂ can interfere with the Wnt canonical pathway, which is essential during early brain development. Higher levels of PGE₂ increased Wnt-dependent motility and proliferation of neuroectodermal stem cells, and modified the expression of Wnt genes previously linked to autism disorders. We also recently established a cross-talk between these two pathways in the prenatal mouse brain lacking PGE₂ producing enzyme (COX^-/-). The current study complements the published data and reveals that PGE₂ signaling also converges with the Wnt canonical pathway in the developing mouse brain after maternal exposure to PGE₂ at the onset of neurogenesis. We found significant changes in the expression level of Wnt-target genes, Mmp7, Wnt2, and Wnt3a, during prenatal and early postnatal stages. Interestingly, we observed variability in the expression level of these genes between genetically-identical pups within the same pregnancy. Furthermore, we found that all the affected genes have been previously associated with disorders of the central nervous system, including autism. We determined that prenatal exposure to PGE₂ affects the Wnt pathway at the level of β-catenin, the major downstream regulator of Wnt-dependent gene transcription. We discuss how these results add new knowledge into the molecular mechanisms by which PGE₂ may interfere with neuronal development during critical periods.

Investigating the effects of environmental factors on autism spectrum disorder in the USA using remotely sensed data

This study aimed to assess the association between exposures to outdoor environmental factors and autism spectrum disorder (ASD) prevalence in a diverse and spatially distributed population of 8-year-old children from the USA (n = 2,097,188) using the air quality index (AQI) of the US Environmental Protection Agency as well as satellite-derived data of PM_2.5 concentrations, sunlight, and maximum heat index. Multivariable logistic regression analyses were performed to determine whether the unhealthy AQI, PM_2.5, sunlight, and maximum heat index were related to the odds of ASD prevalence based on gender and race and taking into consideration the confounding factors of smoking and socioeconomic status. The logistic regression odds ratios for ASD per 10% increase in the unhealthy AQI were greater than 1 for all categories, indicating that unhealthy AQI is related to the odds of ASD prevalence. The odds ratio of ASD due to the exposure to the unhealthy AQI was higher for Asians (OR = 2.96, 95% CI = 1.11-7.88) than that for Hispanics (OR = 1.308, 95% CI = 0.607-2.820), and it was higher for Blacks (OR = 1.398, 95% CI = 0.827-2.364) than that for Whites (OR = 1.219, 95% CI = 0.760-1.954). The odds ratio of ASD due to the unhealthy AQI was slightly higher for males (OR = 1.123, 95% CI = 0.771-1.635) than that for females (OR = 1.117, 95% CI = 0.789-1.581). The effects of the unhealthy environmental exposures on the odds ratios of ASD of this study were inconclusive (i.e., statically insignificant; p value > 0.05) for all categories except for Asians. The odds ratios of ASD for Asians were increased by 5, 12, and 14% with increased levels of the environmental exposures of 10 μg/m³ of PM_2.5, 1000 kJ/m² of sunlight, and 1 °F of maximum heat index, respectively. The odds ratios of ASD prevalence for all categories, except for Asians, were increased with the inclusion of the smoking covariate, reflecting the effect of smoking on ASD prevalence besides the unhealthy environmental factors.

Microarray analysis of gene expression in the cyclooxygenase knockout mice - a connection to autism spectrum disorder

The cellular and molecular events that take place during brain development play an important role in governing function of the mature brain. Lipid-signalling molecules such as prostaglandin E₂ (PGE₂ ) play an important role in healthy brain development. Abnormalities along the COX-PGE₂ signalling pathway due to genetic or environmental causes have been linked to autism spectrum disorder (ASD). This study aims to evaluate the effect of altered COX-PGE₂ signalling on development and function of the prenatal brain using male mice lacking cyclooxygenase-1 and cyclooxygenase-2 (COX-1^-/- and COX-2^-/- ) as potential model systems of ASD. Microarray analysis was used to determine global changes in gene expression during embryonic days 16 (E16) and 19 (E19). Gene Ontology: Biological Process (GO:BP) and Kyoto Encyclopedia of Genes and Genomes (KEGG) were implemented to identify affected developmental genes and cellular processes. We found that in both knockouts the brain at E16 had nearly twice as many differentially expressed genes, and affected biological pathways containing various ASD-associated genes important in neuronal function. Interestingly, using GeneMANIA and Cytoscape we also show that the ASD-risk genes identified in both COX-1^-/- and COX-2^-/- models belong to protein-interaction networks important for brain development despite of different cellular localization of these enzymes. Lastly, we identified eight genes that belong to the Wnt signalling pathways exclusively in the COX-2^-/- mice at E16. The level of PKA-phosphorylated β-catenin (S552), a major activator of the Wnt pathway, was increased in this model, suggesting crosstalk between the COX-2-PGE₂ and Wnt pathways during early brain development. Overall, these results provide further molecular insight into the contribution of the COX-PGE₂ pathways to ASD and demonstrate that COX-1^-/- and COX-2^-/- animals might be suitable new model systems for studying the disorders.

Pre- and Postsurgical Orthodontics in Patients with Moebius Syndrome

The authors report a combined orthodontic-surgical correction of an adult patient's malocclusion affected by Moebius Syndrome (MS). The treatment was conducted at the Dentistry Unit and the Maxillofacial Surgery Unit of the University Hospital of Parma. Treatment of malocclusion was performed after the correction of facial mimic mobility with smile surgery. The postoperative stability and orthodontic results were good and the correction of the morphological problems related to the syndrome was very satisfactory.

Environmental risk factors for autism: an evidence-based review of systematic reviews and meta-analyses

BACKGROUND

According to recent evidence, up to 40-50% of variance in autism spectrum disorder (ASD) liability might be determined by environmental factors. In the present paper, we conducted a review of systematic reviews and meta-analyses of environmental risk factors for ASD. We assessed each review for quality of evidence and provided a brief overview of putative mechanisms of environmental risk factors for ASD.

FINDINGS

Current evidence suggests that several environmental factors including vaccination, maternal smoking, thimerosal exposure, and most likely assisted reproductive technologies are unrelated to risk of ASD. On the contrary, advanced parental age is associated with higher risk of ASD. Birth complications that are associated with trauma or ischemia and hypoxia have also shown strong links to ASD, whereas other pregnancy-related factors such as maternal obesity, maternal diabetes, and caesarian section have shown a less strong (but significant) association with risk of ASD. The reviews on nutritional elements have been inconclusive about the detrimental effects of deficiency in folic acid and omega 3, but vitamin D seems to be deficient in patients with ASD. The studies on toxic elements have been largely limited by their design, but there is enough evidence for the association between some heavy metals (most important inorganic mercury and lead) and ASD that warrants further investigation. Mechanisms of the association between environmental factors and ASD are debated but might include non-causative association (including confounding), gene-related effect, oxidative stress, inflammation, hypoxia/ischemia, endocrine disruption, neurotransmitter alterations, and interference with signaling pathways.

CONCLUSIONS

Compared to genetic studies of ASD, studies of environmental risk factors are in their infancy and have significant methodological limitations. Future studies of ASD risk factors would benefit from a developmental psychopathology approach, prospective design, precise exposure measurement, reliable timing of exposure in relation to critical developmental periods and should take into account the dynamic interplay between gene and environment by using genetically informed designs.

Environmental factors influencing the risk of autism

Autism is a developmental disability with age of onset in childhood (under 3 years old), which is characterized by definite impairments in social interactions, abnormalities in speech, and stereotyped pattern of behaviors. Due to the progress of autism in recent decades, a wide range of studies have been done to identify the etiological factors of autism. It has been found that genetic and environmental factors are both involved in autism pathogenesis. Hence, in this review article, a set of environmental factors involved in the occurrence of autism has been collected, and finally, some practical recommendations for reduction of the risk of this devastating disease in children are represented.

Moebius sequence -a multidisciplinary clinical approach

Background

Moebius Sequence (MS) is a rare disorder defined by bilateral congenital paralysis of the abducens and facial nerves in combination with various odontological, craniofacial, ophthalmological and orthopaedic conditions. The aetiology is still unknown; but both genetic (de novo mutations) and vascular events in utero are reported. The purpose of present study was through a multidisciplinary clinical approach to examine children diagnosed with Moebius-like symptoms. Ten children underwent odontological, ophthalmological, obstetric, paediatric, orthopaedic, genetic, radiological and photographical evaluation. Five patients maintained the diagnosis of MS according to the diagnostic criteria.

Results

All five patients had bilateral facial and abducens paralysis confirmed by ophthalmological examination. Three of five had normal brain MR imaging. Two had missing facial nerves and one had missing abducens nerves. The Strengths and Difficulties Questionnaire (SDQ) showed normal scores in three of five patients. Interestingly, two of five children were born to mothers with uterine abnormalities (unicornuate/bicornuate uterus). In the odontological examination three of five showed enamel hypomineralisation. All five had abnormal orofacial motor function and maxillary prognathism. Two patients had adactyly, syndactyly and brachydactyly. None of the five patients had Poland anomaly, hip dislocation or dysplasia but all had a mild degree of scoliosis. We observed congenital club-feet, calcaneovalgus deformities, macrodactyly of one or more toes or curly toes. Pedobarography showed plantar pressures within normal ranges.

Conclusions

Adherence to standard diagnostic criteria is central in the diagnosis of MS. An accurate diagnosis is the basis for correct discussion of other relevant concomitant symptoms of MS, genetic testing and evaluation of prognosis. The multidisciplinary approach and adherence to diagnostic criteria taken in present study increases the knowledge on the relationship between genotype, phenotype and symptomatology of MS.

Severity of ASD symptoms and their correlation with the presence of copy number variations and exposure to first trimester ultrasound

Current research suggests that incidence and heterogeneity of autism spectrum disorder (ASD) symptoms may arise through a variety of exogenous and/or endogenous factors. While subject to routine clinical practice and generally considered safe, there exists speculation, though no human data, that diagnostic ultrasound may also contribute to ASD severity, supported by experimental evidence that exposure to ultrasound early in gestation could perturb brain development and alter behavior. Here we explored a modified triple hit hypothesis [Williams & Casanova, ] to assay for a possible relationship between the severity of ASD symptoms and (1) ultrasound exposure (2) during the first trimester of pregnancy in fetuses with a (3) genetic predisposition to ASD. We did so using retrospective analysis of data from the SSC (Simon's Simplex Collection) autism genetic repository funded by the Simons Foundation Autism Research Initiative. We found that male children with ASD, copy number variations (CNVs), and exposure to first trimester ultrasound had significantly decreased non-verbal IQ and increased repetitive behaviors relative to male children with ASD, with CNVs, and no ultrasound. These data suggest that heterogeneity in ASD symptoms may result, at least in part, from exposure to diagnostic ultrasound during early prenatal development of children with specific genetic vulnerabilities. These results also add weight to on-going concerns expressed by the FDA about non-medical use of diagnostic ultrasound during pregnancy. Autism Res 2017, 10: 472-484. © 2016 International Society for Autism Research, Wiley Periodicals, Inc.

Genetic Syndromes, Maternal Diseases and Antenatal Factors Associated with Autism Spectrum Disorders (ASD)

Autism spectrum disorder (ASD) affecting about 1% of all children is associated, in addition to complex genetic factors, with a variety of prenatal, perinatal, and postnatal etiologies. In addition, ASD is often an important clinical presentation of some well-known genetic syndromes in human. We discuss these syndromes as well as the role of the more important prenatal factors affecting the fetus throughout pregnancy which may also be associated with ASD. Among the genetic disorders we find Fragile X, Rett syndrome, tuberous sclerosis, Timothy syndrome, Phelan-McDermid syndrome, Hamartoma tumor syndrome, Prader-Willi and Angelman syndromes, and a few others. Among the maternal diseases in pregnancy associated with ASD are diabetes mellitus (PGDM and/or GDM), some maternal autoimmune diseases like antiphospholipid syndrome (APLS) with anti-β2GP1 IgG antibodies and thyroid disease with anti-thyroid peroxidase (TPO) antibodies, preeclampsia and some other autoimmune diseases with IgG antibodies that might affect fetal brain development. Other related factors are maternal infections (rubella and CMV with fetal brain injuries, and possibly Influenza with fever), prolonged fever and maternal inflammation, especially with changes in a variety of inflammatory cytokines and antibodies that cross the placenta and affect the fetal brain. Among the drugs are valproic acid, thalidomide, misoprostol, and possibly SSRIs. β2-adrenergic receptor agonists and paracetamol have also lately been associated with increased rate of ASD but the data is too preliminary and inconclusive. Associations were also described with ethanol, cocaine, and possibly heavy metals, heavy smoking, and folic acid deficiency. Recent studies show that heavy exposure to pesticides and air pollution, especially particulate matter < 2.5 and 10 μm in diameter (PM2.5 and PM10) during pregnancy is also associated with ASD. Finally, we have to remember that many of the associations mentioned in this review are only partially proven, and not all are "clean" of different confounding factors. The associations described in this review emphasize again how little we know about the etiology and pathogenesis of ASD. It is obvious that we need more epidemiologic data to establish many of these associations, but if proven, they might be promising avenues for prevention.

In utero Exposure to β-2-Adrenergic Receptor Agonist Drugs and Risk for Autism Spectrum Disorders

OBJECTIVES

The purpose of this study was to investigate associations between use of β-2-adrenergic receptor (B2AR) agonist drugs during pregnancy and risk for autism spectrum disorders (ASD).

METHODS

A case-control study was conducted by using Denmark's health and population registers. Among children born between 1997 and 2006, 5200 cases with ASD admission diagnoses and 52 000 controls without ASD were identified and individually matched on month and year of birth. Conditional logistic regression models were used to estimate odds ratios (OR) and confidence intervals (CI) for any B2AR agonist exposure during pregnancy, preconception, and by trimester.

RESULTS

In total, 3.7% of cases and 2.9% of controls were exposed to B2ARs during pregnancy. Use of B2ARs during pregnancy was associated with increased risk of ASD, even after adjustment for maternal asthma and other covariates (OR: 1.3, 95% CI: 1.1-1.5). The elevated risk was observed with use of B2AR during preconception (OR: 1.3, 95% CI: 1.0-1.6), first trimester (OR: 1.3, 95% CI: 1.1-1.5), second trimester (OR: 1.5, 95% CI: 1.1-1.7), and the third trimester (OR: 1.4, 95% CI: 1.1-1.7). There was some evidence that longer B2AR within-pregnancy use was associated with the increased risk.

CONCLUSIONS

B2AR agonist exposure during pregnancy may be associated with an increased risk for ASD. If the effect is real, any intervention must be balanced against benefits of indicated medication use by pregnant women.

The Role of mGluR Copy Number Variation in Genetic and Environmental Forms of Syndromic Autism Spectrum Disorder

While abnormal signaling mediated through metabotropic glutamate receptor 5 (mGluR5) is involved in the pathophysiology of Autism Spectrum Disorder (ASD), Fragile X Syndrome and Tuberous Sclerosis, the role of other mGluRs and their associated signaling network genes in syndromic ASD is unknown. This study sought to determine whether mGluR Copy Number Variants (CNV's) were overrepresented in children with syndromic ASD and if mGluR "second hit" confers additional risk for ASD in 22q11.2 Deletion Syndrome (22q11DS). To determine whether mGluR network CNV'S are enriched in syndromic ASD, we examined microarrays from children with ASD (n = 539). Patient categorization (syndromic vs nonsyndromic) was done via blinded medical chart review in mGluR positive and randomly selected mGluR negative cases. 11.5% of ASD had mGluR CNV's vs. 3.2% in controls (p < 0.001). Syndromic ASD was more prevalent in children with mGluR CNVs (74% vs 16%, p < 0.001). A comparison cohort with 22q11DS (n = 25 with ASD, n = 50 without ASD), all haploinsufficient for mGluR network gene RANBP1, were evaluated for "second mGluR hits". 20% with 22q11.2DS + ASD had "second hits" in mGluR network genes vs 2% in 22q11.2DS-ASD (p < 0.014). We propose that altered RANBP1 expression may provide a mechanistic link for several seemingly unrelated genetic and environmental forms of ASD.

Prenatal factors associated with autism spectrum disorder (ASD)

Autism spectrum disorder (ASD) affecting about 1% of all children is associated, in addition to complex genetic factors, with a variety of prenatal, perinatal and postnatal etiologies. We discuss the known associated prenatal factors affecting the fetus throughout pregnancy; whenever relevant, also summarize some animal data. Among the maternal diseases in pregnancy associated with ASD are pregestational and/or gestational diabetes mellitus (PGDM, GDM), maternal infections (i.e. rubella, cytomegalovirus (CMV)), prolonged fever and maternal inflammation, which cause changes in a variety of inflammatory cytokines. Among the drugs are valproic acid, thalidomide, and possibly misoprostol and serotonin reuptake inhibitors (SSRIs). Associations were described with ethanol, and possibly cocaine, heavy metals heavy smoking and Folic acid deficiency. Heavy exposure to pesticides and air pollution during pregnancy was recently associated with ASD. We need more epidemiologic data to establish many of these associations; if proven, they might be promising avenues for prevention.

Atraumatic restorative technique: case report on dental management of a patient with Moebius syndrome

BACKGROUND

Clinical challenges associated with Moebius syndrome, a rare congenital neuromuscular disorder, include orofacial anomalies like microstomia, limited mouth opening and severe gag reflex.

METHODS

This case report presents the dental management of an anxious female with Moebius syndrome. For restorations, atraumatic restorative technique (ART), using glass ionomer cement was used with hand instruments.

RESULTS

All necessary dental treatment was completed in the dental chair, thus avoiding the need for a general anaesthetic, and associated complications with airway management due to orofacial abnormalities.

CONCLUSIONS

ART is an appropriate technique for people with microstomia and/or limited mouth opening, such as those with Moebius syndrome. The application of ART can be extended to other special needs patients (people with physical and intellectual disabilities, extreme anxiety, needle phobia and the frail elderly in aged care facilities), where access or cooperation is difficult or limited.

The association between congenital anomalies and autism spectrum disorders in a Finnish national birth cohort

AIM

The first aim of this study was to evaluate the association between different subgroups of autism spectrum disorders (ASDs) (childhood autism, Asperger syndrome, and pervasive developmental disorder/pervasive developmental disorder - not otherwise specified [PDD/PDD-NOS]) and congenital anomalies. Second, we assessed the association among intellectually disabled children with ASDs in the subgroups of childhood autism and PDD/PDD-NOS.

METHOD

Nationwide population-based register data for children with a diagnosis of ASD (n=4449; 3548 males, 901 females) were collected during years 1987-2000 from the Finnish Hospital Discharge Register. Data on congenital anomalies were derived from the National Register of Congenital Malformations. Conditional logistic regression models were used as a statistical method. The association between ASD subgroups and congenital anomalies was stratified by the presence or absence of intellectual disability.

RESULTS

Congenital anomalies occurred more frequently in all subgroups of ASD than in comparison participants (adjusted odds ratio [OR] for major congenital anomalies 1.8, 95% confidence interval [CI] 1.5-2.2, p<0.001). The association between congenital anomalies and childhood autism (OR 2.4, 95% CI 1.6-3.6, p<0.001) and between congenital anomalies and PDD/PDD-NOS (OR 3.7, 95% CI 2.4-5.7, p<0.001) among children with an intellectual disability was strong but remained significant also without intellectual disability (childhood autism: OR 1.7, 95% CI 1.3-2.3, p<0.001; PDD/PDD-NOS: OR 2.3, 95% CI 1.9-2.8, p<0.001).

INTERPRETATION

The results suggest a significant association between ASDs and congenital anomalies regardless of the ASD subgroup. The association between childhood autism and PDD/PDD-NOS and congenital anomalies is stronger among children with intellectual disability is stronger than among those without intellectual disability. These results may have relevance in examining early risk factors in autism during fetal neurodevelopment.

Autism as a sequence: from heterochronic germinal cell divisions to abnormalities of cell migration and cortical dysplasias

The considerable heterogeneity in the number and severity of symptoms observed in autism spectrum disorders (ASD) has been regarded as an obstacle to any future research. Some authors believe that clinical heterogeneity results from the complex interplay of the many genetic and environmental factors that themselves define a condition as multifactorial. However, it is important to note that neuropathological findings in both idiopathic and syndromic autism suggests a single pathophysiological mechanism acting during brain development: the heterochronic division of germinal cells and subsequent migrational abnormalities of daughter cells to their target fields. Multiple exogenous (e.g., viruses, drugs) and endogenous (e.g., genetic mutations) factors are known to disrupt the division of germinal cells and provide for an autism phenotype. The variety of endogenous and exogenous factors, their timing of action during brain development, and the genetic susceptibility of affected individuals (a Triple Hit hypothesis) may all account for the clinical heterogeneity of ASD.

Prostaglandin E2 alters Wnt-dependent migration and proliferation in neuroectodermal stem cells: implications for autism spectrum disorders

Prostaglandin E2 (PGE₂) is a natural lipid-derived molecule that is involved in important physiological functions. Abnormal PGE₂ signalling has been associated with pathologies of the nervous system. Previous studies provide evidence for the interaction of PGE₂ and canonical Wnt signalling pathways in non-neuronal cells. Since the Wnt pathway is crucial in the development and organization of the brain, the main goal of this study is to determine whether collaboration between these pathways exists in neuronal cell types. We report that PGE₂ interacts with canonical Wnt signalling through PKA and PI-3K in neuroectodermal (NE-4C) stem cells. We used time-lapse microscopy to determine that PGE₂ increases the final distance from origin, path length travelled, and the average speed of migration in Wnt-activated cells. Furthermore, PGE₂ alters distinct cellular phenotypes that are characteristic of Wnt-induced NE-4C cells, which corresponds to the modified splitting behaviour of the cells. We also found that in Wnt-induced cells the level of β-catenin protein was increased and the expression levels of Wnt-target genes (Ctnnb1, Ptgs2, Ccnd1, Mmp9) was significantly upregulated in response to PGE₂ treatment. This confirms that PGE₂ activated the canonical Wnt signalling pathway. Furthermore, the upregulated genes have been previously associated with ASD. Our findings show, for the first time, evidence for cross-talk between PGE₂ and Wnt signalling in neuronal cells, where PKA and PI-3K might act as mediators between the two pathways. Given the importance of PGE₂ and Wnt signalling in prenatal development of the nervous system, our study provides insight into how interaction between these two pathways may influence neurodevelopment.

Reorganization of circuits underlying cerebellar modulation of prefrontal cortical dopamine in mouse models of autism spectrum disorder

Imaging, clinical, and pre-clinical studies have provided ample evidence for a cerebellar involvement in cognitive brain function including cognitive brain disorders, such as autism and schizophrenia. We previously reported that cerebellar activity modulates dopamine release in the mouse medial prefrontal cortex (mPFC) via two distinct pathways: (1) cerebellum to mPFC via dopaminergic projections from the ventral tegmental area (VTA) and (2) cerebellum to mPFC via glutamatergic projections from the mediodorsal and ventrolateral thalamus (ThN md and vl). The present study compared functional adaptations of cerebello-cortical circuitry following developmental cerebellar pathology in a mouse model of developmental loss of Purkinje cells (Lurcher) and a mouse model of fragile X syndrome (Fmr1 KO mice). Fixed potential amperometry was used to measure mPFC dopamine release in response to cerebellar electrical stimulation. Mutant mice of both strains showed an attenuation in cerebellar-evoked mPFC dopamine release compared to respective wildtype mice. This was accompanied by a functional reorganization of the VTA and thalamic pathways mediating cerebellar modulation of mPFC dopamine release. Inactivation of the VTA pathway by intra-VTA lidocaine or kynurenate infusions decreased dopamine release by 50 % in wildtype and 20-30 % in mutant mice of both strains. Intra-ThN vl infusions of either drug decreased dopamine release by 15 % in wildtype and 40 % in mutant mice of both strains, while dopamine release remained relatively unchanged following intra-ThN md drug infusions. These results indicate a shift in strength towards the thalamic vl projection, away from the VTA. Thus, cerebellar neuropathologies associated with autism spectrum disorders may cause a reduction in cerebellar modulation of mPFC dopamine release that is related to a reorganization of the mediating neuronal pathways.

Oral motor assessment in individuals with Moebius syndrome

BACKGROUND

Moebius syndrome (MS) is a rare congenital condition that is characterised by facial hypomimia and congenital strabismus caused by complete or partial impairment of the 6th and 7th cranial nerves. MS may be further associated with other nerves or malformations, mainly involving the extremities. The objective of this study was to quantify the decrease in oral motor performance in people with MS compared with normoreactive individuals using the Oral Motor Assessment Scale (OMAS).

METHODS

The study group comprised 33 subjects between the ages of 2 and 20 years (average age: 10 ± 5 years) with MS along with 46 age- and gender-matched control subjects.

RESULTS

The study group displayed a lower average functional score than the control group (P < 0.0001). A significant lack of lip closure (P = 0.03) and anterior lingual seal during swallowing (P = 0.03) occurred in the study group; in most cases, the individuals with MS were classified as 'subfunctional'. In addition, individuals with MS in the older age group displayed better functional scores than those in the younger group (P = 0.05).

CONCLUSIONS

Functional damage to oral motor function in individuals with MS is evident, but differs among patients with respect to severity and the movements that are compromised. However, overall, improvements in the functional patterns of these individuals can be observed as they mature in age.

General developmental health in the VPA-rat model of autism

Autism is a neurodevelopmental condition diagnosed by impaired social interaction, abnormal communication and, stereotyped behaviors. While post-mortem and imaging studies have provided good insights into the neurobiological symptomology of autism, animal models can be used to study the neuroanatomical, neurophysiological and molecular mediators in more detail and in a more controlled environment. The valproic acid (VPA) rat model is an environmentally triggered model with strong construct and clinical validity. It is based on VPA teratogenicity in humans, where mothers who are medicated with VPA during early pregnancy show an increased risk for giving birth to an autistic child. In rats, early embryonic exposure, around the time of neural tube closure, leads to autism-like anatomical and behavioral abnormalities in the offspring. Considering the increasing use of the VPA rat model, we present our observations of the general health of Wistar dams treated with a single intraperitoneal injection of 500 or, 600 mg/kg VPA on embryonic day E12.5, as well as their male and female offspring, in comparison to saline-exposed controls. We report increased rates of complete fetal reabsorption after both VPA doses. VPA 500 mg/kg showed no effect on dam body weight during pregnancy or, on litter size. Offspring exposed to VPA 500 mg/kg showed smaller brain mass on postnatal days 1 (P1) and 14 (P14), in addition to abnormal nest seeking behavior at P10 in the olfactory discrimination test, relative to controls. We also report increased rates of physical malformations in the offspring, rare occurrences of chromodacryorrhea and, developmentally similar body mass gain. Further documentation of developmental health may guide sub-grouping of individuals in a way to better predict core symptom severity.

Autism spectrum disorders: the quest for genetic syndromes

Autism spectrum disorders (ASD) are a heterogeneous group of neurodevelopmental disabilities with various etiologies, but with a heritability estimate of more than 90%. Although the strong correlation between autism and genetic factors has been long established, the exact genetic background of ASD remains unclear. A number of genetic syndromes manifest ASD at higher than expected frequencies compared to the general population. These syndromes account for more than 10% of all ASD cases and include tuberous sclerosis, fragile X, Down, neurofibromatosis, Angelman, Prader-Willi, Williams, Duchenne, etc. Clinicians are increasingly required to recognize genetic disorders in individuals with ASD, in terms of providing proper care and prognosis to the patient, as well as genetic counseling to the family. Vice versa, it is equally essential to identify ASD in patients with genetic syndromes, in order to ensure correct management and appropriate educational placement. During investigation of genetic syndromes, a number of issues emerge: impact of intellectual disability in ASD diagnoses, identification of autistic subphenotypes and differences from idiopathic autism, validity of assessment tools designed for idiopathic autism, possible mechanisms for the association with ASD, etc. Findings from the study of genetic syndromes are incorporated into the ongoing research on autism etiology and pathogenesis; different syndromes converge upon common biological backgrounds (such as disrupted molecular pathways and brain circuitries), which probably account for their comorbidity with autism. This review paper critically examines the prevalence and characteristics of the main genetic syndromes, as well as the possible mechanisms for their association with ASD.

Is autism a disease of the cerebellum? An integration of clinical and pre-clinical research

Autism spectrum disorders are a group of neurodevelopmental disorders characterized by deficits in social skills and communication, stereotyped and repetitive behavior, and a range of deficits in cognitive function. While the etiology of autism is unknown, current research indicates that abnormalities of the cerebellum, now believed to be involved in cognitive function and the prefrontal cortex (PFC), are associated with autism. The current paper proposes that impaired cerebello-cortical circuitry could, at least in part, underlie autistic symptoms. The use of animal models that allow for manipulation of genetic and environmental influences are an effective means of elucidating both distal and proximal etiological factors in autism and their potential impact on cerebello-cortical circuitry. Some existing rodent models of autism, as well as some models not previously applied to the study of the disorder, display cerebellar and behavioral abnormalities that parallel those commonly seen in autistic patients. The novel findings produced from research utilizing rodent models could provide a better understanding of the neurochemical and behavioral impact of changes in cerebello-cortical circuitry in autism.

Prenatal exposures associated with neurodevelopmental delay and disabilities

Neurobehavioral teratology refers to the study of the abnormal development of the structure and the behavioral functions of the central nervous system, which result from exposure to exogenous agents during prenatal development. The focus of this review is the effects of various prenatal exposures on human neurodevelopment. Studies that deal with the adverse effects of infectious agents (rubella, cytomegalovirus, and toxoplasma), teratogenic drugs (e.g., antiepileptic drugs such as phenytoin, valproate, and carbamazepine, coumarin derivatives, and retinoids), alcohol, and other substances of abuse will be reviewed. Additionally, prenatal exposure to industrial or environmental chemicals (e.g., lead, methylmercury, and polycarbonated biphenyls) as well as exposure of the embryo or fetus to high amounts of ionizing radiation will be addressed. Possible mechanisms of selected neurobehavioral teratogens will also be discussed.

Lack of evidence for neonatal misoprostol neurodevelopmental toxicity in C57BL6/J mice

Misoprostol is a synthetic analogue of prostaglandin E1 that is administered to women at high doses to induce uterine contractions for early pregnancy termination and at low doses to aid in cervical priming during labor. Because of the known teratogenic effects of misoprostol when given during gestation and its effects on axonal growth in vitro, we examined misoprostol for its potential as a neurodevelopmental toxicant when administered to neonatal C57BL6/J mice. Mice were injected subcutaneously (s.c.) with 0.4, 4 or 40 µg/kg misoprostol on postnatal day 7, the approximate developmental stage in mice of human birth, after which neonatal somatic growth, and sensory and motor system development were assessed. These doses were selected to span the range of human exposure used to induce labor. In addition, adult mice underwent a battery of behavioral tests relevant to neurodevelopmental disorders such as autism including tests for anxiety, stereotyped behaviors, social communication and interactions, and learning and memory. No significant effects of exposure were found for any measure of development or behavioral endpoints. In conclusion, the results of the present study in C57BL/6J mice do not provide support for neurodevelopmental toxicity after misoprostol administration approximating human doses and timed to coincide with the developmental stage of human birth.

What can we learn from the thalidomide experience: an ophthalmologic perspective

PURPOSE OF REVIEW

The thalidomide tragedy of the early 1960s resulted in a great number of studies and reports involving many specialties of medicine. Because of the estimated large number of affected children (5000+) worldwide exposed to this potent teratogen, and the many informative cases in which the exposure time was known, a teratogenic timetable was constructed relating affected structures to the time of exposure. This demonstrated that thalidomide had a teratogenic effect between approximately 20 to 36 days after fertilization.

RECENT FINDINGS

We found that Duane syndrome and its variants were prominent in individuals who were exposed to thalidomide early in the sensitive period (days 20 to 26±). Other anomalies associated with this early effect were aberrant tearing, facial nerve palsy, ear malformations, and autism. Structural eye malformations were less frequent in this early phase, appearing slightly later in the sensitive period.

SUMMARY

This study summarizes the ophthalmologic findings from a number of studies and compares them with respect to the implications of time of exposure. Because the timing of anomalies such as external ear and limb malformations are well established in the thalidomide literature, correlation with associated eye anomalies gives insight into the approximate timing of the causative teratogen exposure.

Autism spectrum disorders--a genetics review

Autism is an etiologically and clinically heterogeneous group of disorders, diagnosed solely by the complex behavioral phenotype. On the basis of the high-heritability index, geneticists are confident that autism will be the first behavioral disorder for which the genetic basis can be well established. Although it was initially assumed that major genome-wide and candidate gene association studies would lead most directly to common autism genes, progress has been slow. Rather, most discoveries have come from studies of known genetic disorders associated with the behavioral phenotype. New technology, especially array chromosomal genomic hybridization, has both increased the identification of putative autism genes and raised to approximately 25%, the percentage of children for whom an autism-related genetic change can be identified. Incorporating clinical geneticists into the diagnostic and autism research arenas is vital to the field. Interpreting this new technology and deciphering autism's genetic montage require the skill set of the clinical geneticist including knowing how to acquire and interpret family pedigrees, how to analyze complex morphologic, neurologic, and medical phenotypes, sorting out heterogeneity, developing rational genetic models, and designing studies. The current emphasis on deciphering autism spectrum disorders has accelerated the field of neuroscience and demonstrated the necessity of multidisciplinary research that must include clinical geneticists both in the clinics and in the design and implementation of basic, clinical, and translational research.

The role of neurotrophic factors in autism

Autism spectrum disorders (ASDs) are pervasive developmental disorders that frequently involve a triad of deficits in social skills, communication and language. For the underlying neurobiology of these symptoms, disturbances in neuronal development and synaptic plasticity have been discussed. The physiological development, regulation and survival of specific neuronal populations shaping neuronal plasticity require the so-called 'neurotrophic factors' (NTFs). These regulate cellular proliferation, migration, differentiation and integrity, which are also affected in ASD. Therefore, NTFs have gained increasing attention in ASD research. This review provides an overview and explores the key role of NTFs in the aetiology of ASD. We have also included evidence derived from neurochemical investigations, gene association studies and animal models. By focussing on the role of NTFs in ASD, we intend to further elucidate the puzzling aetiology of these conditions.

Environmental risk factors for autism

Autism is a devastating childhood condition that has emerged as an increasing social concern just as it has increased in prevalence in recent decades. Autism and the broader category of autism spectrum disorders are among the increasingly seen examples in which there is a fetal basis for later disease or disorder. Environmental, genetic, and epigenetic factors all play a role in determining the risk of autism and some of these effects appear to be transgenerational. Identification of the most critical windows of developmental vulnerability is paramount to understanding when and under what circumstances a child is at elevated risk for autism. No single environmental factor explains the increased prevalence of autism. While a handful of environmental risk factors have been suggested based on data from human studies and animal research, it is clear that many more, and perhaps the most significant risk factors, remain to be identified. The most promising risk factors identified to date fall within the categories of drugs, environmental chemicals, infectious agents, dietary factors, and other physical/psychological stressors. However, the rate at which environmental risk factors for autism have been identified via research and safety testing has not kept pace with the emerging health threat posed by this condition. For the way forward, it seems clear that additional focused research is needed. But more importantly, successful risk reduction strategies for autism will require more extensive and relevant developmental safety testing of drugs and chemicals.

The neurobiology of lipid metabolism in autism spectrum disorders

Autism is a neurodevelopmental disorder characterized by impairments in communication and reciprocal social interaction, coupled with repetitive behavior, which typically manifests by 3 years of age. Multiple genes and early exposure to environmental factors are the etiological determinants of the disorder that contribute to variable expression of autism-related traits. Increasing evidence indicates that altered fatty acid metabolic pathways may affect proper function of the nervous system and contribute to autism spectrum disorders. This review provides an overview of the reported abnormalities associated with the synthesis of membrane fatty acids in individuals with autism as a result of insufficient dietary supplementation or genetic defects. Moreover, we discuss deficits associated with the release of arachidonic acid from the membrane phospholipids and its subsequent metabolism to bioactive prostaglandins via phospholipase A(2)-cyclooxygenase biosynthetic pathway in autism spectrum disorders. The existing evidence for the involvement of lipid neurobiology in the pathology of neurodevelopmental disorders such as autism is compelling and opens up an interesting possibility for further investigation of this metabolic pathway.

Moebius sequence and autism spectrum disorders--less frequently associated than formerly thought

Moebius sequence is a rare congenital disorder usually defined as a combination of facial weakness with impairment of ocular abduction. It is questionable, whether there is a strong association of the sequence with autism spectrum disorders (ASDs) as suggested in some earlier case reports and studies. Twenty-two participants with Möbius sequence aged 6-16 years followed a request of the German Moebius foundation to participate in a nationwide study. All patients had a physical examination and intelligence testing. Primary caregivers were asked to complete two screening measures of ASD (Behaviour and Communication Questionnaire, VSK; Marburger Asperger's Syndrome Rating Scale, MBAS). For those who reached the cut-off for ASD and/or showed behavioural aspects indicative of ASDs during IQ testing and/or physical examination, well standardized diagnostic instruments (Autism Diagnostic Interview-Revised, Autism Diagnostic Observation Schedule, and Kinder-DIPS) were administered. Minimal diagnostic criteria for Möbius sequence were congenital facial weakness (uni- or bilateral) and impairment of ocular abduction (uni- or bilateral). Three boys (one of them mentally retarded) out of 22 participants (12 males and 10 females) were found suspicious of ASD by screening, but none of them fulfilled diagnostic criteria of ASD on a clinical consensus conference. Therefore, ASDs seem to be not as frequent as reported in previous studies on patients with Möbius sequence.

Misoprostol elevates intracellular calcium in Neuro-2a cells via protein kinase A

Misoprostol, a prostaglandin type E analogue, has been implicated in a number of neurodevelopmental disorders. However, its mode of action in the nervous system is not well understood. Misoprostol acts on the same receptors as prostaglandin E(2) (PGE(2)), a natural lipid-derived compound, which mediates important physiological functions in the nervous system via activation of four EP receptors (EP1-4). In this study we use a ratiometric calcium imaging with fura-2 AM as a calcium indicator to show that misoprostol alters intracellular calcium levels in mouse neuroblastoma (Neuro-2a) cells via similar mechanisms as PGE(2). We demonstrate that the misoprostol-induced increase in calcium is mediated by a protein kinase A (PKA)-dependent mechanism and that the EP4 receptor signaling pathway may play an inhibitory role on calcium regulation. Overall, this study provides further support for the involvement of PGE(2) signaling in calcium homeostasis and suggests its important role in the nervous system.

The association between autism and errors in early embryogenesis: what is the causal mechanism?

The association between embryonic errors and the development of autism has been recognized in the literature, but the mechanism underlying this association remains unknown. We propose that pleiotropic effects during a very early and specific stage of embryonic development-early organogenesis-can explain this association. In humans early organogenesis is an embryonic stage, spanning Day 20 to Day 40 after fertilization, which is characterized by intense interactivity among body parts of the embryo. This implies that a single mutation or environmental disturbance affecting development at this stage can have several phenotypic effects (i.e., pleiotropic effects). Disturbances during early organogenesis can lead to many different anomalies, including limb deformities, craniofacial malformations, brain pathology, and anomalies in other organs. We reviewed the literature and found ample evidence for the association between autism and different kinds of physical anomalies, which agrees with the hypothesis that pleiotropic effects are involved in the development of autism. The proposed mechanism integrates findings from a variety of studies on autism, including neurobiological studies and studies on physical anomalies and prenatal influences on neurodevelopmental outcomes. The implication is that the origin of autism can be much earlier in embryologic development than has been frequently reported.

What causes autism? Exploring the environmental contribution

PURPOSE OF REVIEW

Autism is a biologically based disorder of brain development. Genetic factors--mutations, deletions, and copy number variants--are clearly implicated in causation of autism. However, they account for only a small fraction of cases, and do not easily explain key clinical and epidemiological features. This suggests that early environmental exposures also contribute. This review explores this hypothesis.

RECENT FINDINGS

Indirect evidence for an environmental contribution to autism comes from studies demonstrating the sensitivity of the developing brain to external exposures such as lead, ethyl alcohol and methyl mercury. But the most powerful proof-of-concept evidence derives from studies specifically linking autism to exposures in early pregnancy - thalidomide, misoprostol, and valproic acid; maternal rubella infection; and the organophosphate insecticide, chlorpyrifos. There is no credible evidence that vaccines cause autism.

SUMMARY

Expanded research is needed into environmental causation of autism. Children today are surrounded by thousands of synthetic chemicals. Two hundred of them are neurotoxic in adult humans, and 1000 more in laboratory models. Yet fewer than 20% of high-volume chemicals have been tested for neurodevelopmental toxicity. I propose a targeted discovery strategy focused on suspect chemicals, which combines expanded toxicological screening, neurobiological research and prospective epidemiological studies.

Living with Moebius Syndrome: Adjustment, Social Competence, and Satisfaction with Life

Context

Moebius syndrome is a rare congenital condition that results in bilateral facial paralysis. Several studies have reported social interaction and adjustment problems in people with Moebius syndrome and other facial movement disorders, presumably resulting from lack of facial expression.

Objective

To determine whether adults with Moebius syndrome experience increased anxiety and depression and/or decreased social competence and satisfaction with life compared with people without facial movement disorders.

Design

Internet-based quasi-experimental study with comparison group.

Participants

Thirty-seven adults with Moebius syndrome recruited through the United States–based Moebius Syndrome Foundation newsletter and Web site and 37 age- and gender-matched control participants recruited through a university participant database.

Measures

Anxiety and depression, social competence, satisfaction with life, ability to express emotion facially, and questions about Moebius syndrome symptoms.

Results

People with Moebius syndrome reported significantly lower social competence than the matched control group and normative data but did not differ significantly from the control group or norms in anxiety, depression, or satisfaction with life. In people with Moebius syndrome, degree of facial expression impairment was not significantly related to the adjustment variables.

Conclusions

Many people with Moebius syndrome are better adjusted than previous research suggests, despite their difficulties with social interaction. To enhance interaction, people with Moebius syndrome could compensate for the lack of facial expression with alternative expressive channels.

Thalidomide and misoprostol: Ophthalmologic manifestations and associations both expected and unexpected

Thalidomide is a very potent teratogen capable of causing severe systemic malformations if the fetus is exposed during the sensitive period. Although structural anomalies of the eye can occur from thalidomide exposure, the most frequent eye complication is secondary to damage to the cranial nuclei in the brain stem, resulting in aberrant neurologic connections causing a condition of abnormal ocular movement, Duane syndrome. A less frequent anomalous neurologic complication is tearing when eating (paradoxical gustolacrimal tearing or "crocodile tears") or lack of emotional tearing. The involvement of the 6th and 7th cranial nerves, often seen together in the thalidomide-affected individual, is also characteristic of Möbius syndrome/sequence. This syndrome usually occurs sporadically, but characteristic findings of this condition have also been observed in South American children who were born after an unsuccessful attempt to induce abortion with the prostaglandin drug misoprostol (Cytotec). Aberrant tearing also occurs in some individuals with Möbius syndrome. Autism spectrum disorder (ASD), an unexpected associated finding in a Swedish thalidomide study, is now also noted in Möbius studies, in patients both with and without exposure to misoprostol.