Prevalence of autism in a US metropolitan area

Environmental mercury release, special education rates, and autism disorder: an ecological study of Texas

The association between environmentally released mercury, special education and autism rates in Texas was investigated using data from the Texas Education Department and the United States Environmental Protection Agency. A Poisson regression analysis adjusted for school district population size, economic and demographic factors was used. There was a significant increase in the rates of special education students and autism rates associated with increases in environmentally released mercury. On average, for each 1,000 lb of environmentally released mercury, there was a 43% increase in the rate of special education services and a 61% increase in the rate of autism. The association between environmentally released mercury and special education rates were fully mediated by increased autism rates. This ecological study suggests the need for further research regarding the association between environmentally released mercury and developmental disorders such as autism. These results have implications for policy planning and cost analysis.

Genomic and functional profiling of duplicated chromosome 15 cell lines reveal regulatory alterations in UBE3A-associated ubiquitin–proteasome pathway processes

Autism is a complex neurodevelopmental disorder having both genetic and epigenetic etiological elements. Isodicentric chromosome 15 (Idic15), characterized by duplications of the multi-disorder critical region of 15q11-q14, is a relatively common cytogenetic event. When the duplication involves maternally derived content, this abnormality is strongly correlated with autism disorder. However, the mechanistic links between Idic15 and autism are ill-defined. To gain insight into the potential role of these duplications, we performed a comprehensive, genomics-based characterization of an in vitro model system consisting of lymphoblast cell lines derived from individuals with both autism and Idic15. Array-based comparative genomic hybridization using commercial single nucleotide polymorphism arrays was conducted and found to be capable of sub-classifying Idic15 samples by virtue of the lengths of the duplicated chromosomal region. In further analysis, whole-genome expression profiling revealed that 112 transcripts were significantly dysregulated in samples harboring duplications. Paramount among changing genes was ubiquitin protein ligase E3A (UBE3A; 15q11-q13), which was found to be nearly 1.5-2.0-fold up-regulated in duplicated samples at both the RNA and protein levels. Other key findings from gene expression analysis included two down-regulated genes, APP and SUMO1, with well-characterized roles in the process of apoptosis. We further demonstrate in this lymphoblast model that the gene-dosage directed increases in UBE3A levels can lead to dysregulation of the process of ubiquitination in response to genotoxic insult. This study provides insight into the direct and indirect effects of copy number gains in chromosome 15 and provides a framework for the study of these effects in neuronal systems.

The prevalence of autistic spectrum disorder in children surveyed in a tertiary care epilepsy clinic

It is well documented that children with autistic spectrum disorder (ASD) have an increased prevalence of seizures; however, studies have not been done to evaluate the prevalence of ASD in children with epilepsy. This comorbidity is important to define as early diagnosis and intervention in some children with ASD has been shown to improve outcome.

METHOD

Children with epilepsy seen in a tertiary care epilepsy clinic were evaluated using validated autism screening questionnaires (ASQ). In addition, questions about sleep-related disorders, behavior, seizure characteristics, antiepileptic agents, and body mass index (BMI) were requested. An attempt was then made to determine if there was a correlation between the factors identified and ASD.

RESULTS

Of the 107 questionnaires returned, 97 ASQ's were properly completed and used in this study. Approximately 32% of children fit the ASQ criteria for having ASD. Most children had not been previously diagnosed. Worst behavior and daytime sleepiness was seen in those at greater risk (p < 0.01). Seizures also occurred earlier (approximately 2 years) in children at risk of having ASD.

CONCLUSION

Though confirmatory diagnostic evaluations are needed, this questionnaire-based study suggests that children with epilepsy are at greater risk of having ASD, and illustrates the need for more clinical vigilance. Behavioral difficulties and daytime sleepiness identified in these children could potentially affect their ability to learn. It is of interest that the age of seizure onset identified in those at greater risk corresponds with the approximate age of regression identified in some children with ASD.

Systematic review of prevalence studies of autism spectrum disorders

AIM

To quantitatively examine the influence of study methodology and population characteristics on prevalence estimates of autism spectrum disorders.

METHODS

Electronic databases and bibliographies were searched and identified papers evaluated against inclusion criteria. Two groups of studies estimated the prevalence of typical autism and all autism spectrum disorders (ASD). The extent of variation among studies and overall prevalence were estimated using meta-analysis. The influence of methodological factors and population characteristics on estimated prevalence was investigated using meta-regression and summarised as odds ratios (OR).

RESULTS

Forty studies met inclusion criteria, of which 37 estimated the prevalence of typical autism, and 23 the prevalence of all ASD. A high degree of heterogeneity among studies was observed. The overall random effects estimate of prevalence across studies of typical autism was 7.1 per 10,000 (95% CI 1.6 to 30.6) and of all ASD was 20.0 per 10,000 (95% CI 4.9 to 82.1). Diagnostic criteria used (ICD-10 or DSM-IV versus other; OR = 3.36, 95% CI 2.07 to 5.46), age of the children screened (OR = 0.91 per year, 95% CI 0.83 to 0.99), and study location (e.g. Japan versus North America; OR = 3.60, 95% CI 1.73 to 7.46) were all significantly associated with prevalence of typical autism. Diagnostic criteria, age of the sample, and urban or rural location were associated with estimated prevalence of all ASD.

CONCLUSIONS

Sixty one per cent of the variation in prevalence estimates of typical autism was explained by these models. Diagnostic criteria used, age of children screened, and study location may be acting as proxies for other study characteristics and require further investigation.

Cure therapeutics and strategic prevention: raising the bar for mental health research

Mental disorders cause more disability than any other class of medical illness in Americans between ages 15 and 44 years. The suicide rate is higher than the annual mortality from homicide, AIDS, and most forms of cancer. In contrast to nearly all communicable and most non-communicable diseases, there is little evidence that the morbidity and mortality from mental disorders have changed in the past several decades. Mental health advocates, including psychiatric researchers, have pointed to stigma as one of the reasons for the lack of progress with mental illnesses relative to other medical illnesses. This review considers how the expectations and goals of the research community have contributed to this relative lack of progress. In contrast to researchers in cancer and heart disease who have sought cures and preventions, biological psychiatrists in both academia and industry have set their sights on incremental and marketable advances, such as drugs with fewer adverse effects. This essay argues for approaches that can lead to cures and strategies for prevention of schizophrenia and mood disorders.

10-year research update review: the epidemiology of child and adolescent psychiatric disorders: II. Developmental epidemiology

OBJECTIVE

To describe the growth of developmental epidemiology in the past decade and to illustrate it with examples of recent studies.

METHOD

A review of publications on developmental epidemiology in the past 10 years and a discussion of some key examples.

RESULTS

The authors describe how the interaction between developmental psychopathology and psychiatric epidemiology has produced developmental epidemiology, the study of patterns of distribution of psychiatric disorders in time as well as in space. They give two examples of the kinds of questions that developmental epidemiology can help to answer: (1) Is the prevalence of autism increasing? Does the use of vaccines explain the increase? (2) Is there an epidemic of child and adolescent depression? Finally, they describe two areas of science that are beginning to inform developmental epidemiology: molecular genetics and the use of biological measures of stress.

CONCLUSIONS

While child and adolescent psychiatric epidemiology continues, as described in the first of these reviews, to address questions of prevalence and burden, it has also expanded into new areas of research in the past decade. In the next decade, longitudinal epidemiological data sets with their rich descriptive data on psychopathology and environmental risk over time and the potential to add biological measures will provide valuable resources for research into gene-environment correlations and interactions.

Autism spectrum disorders and symptoms in children with molecularly confirmed 22q11.2 deletion syndrome

In this study, we assessed the presence of autism spectrum disorders (ASD) among children with a confirmed 22q11.2 deletion (n = 98). The children's caregivers completed screening measures of ASD behaviors, and for those whose scores indicated significant levels of these behaviors, a standardized diagnostic interview (Autism Diagnostic Interview-Revised; ADI-R) was administered. Results demonstrated that over 20% of children (n = 22) were exhibiting significant levels of autism spectrum symptoms based on the screening measures. Based upon the ADI-R, 14 children qualified for a diagnosis of an ASD, and for 11 of those children a diagnosis of autism was most appropriate. These findings increase our knowledge of developmental disorders associated with the 22q11.2 deletion and point to avenues for future investigation.

The neuropathology of autism: a review

Presented is a review of recent progress in the understanding of autism based on investigations of donated human brain tissue. Autism is a pervasive developmental disorder by the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) criteria, manifesting by age 3 and characterized by impairments in social interaction and communication, as well as restricted, repetitive, stereotyped patterns of behavior. Based on reported neuropathologic findings, these characteristic behaviors are clinical manifestations of both pre- and postnatal alterations. This review summarizes the current data obtained from postmortem brain studies in the areas of stereology, neurotransmitter systems/synaptic processes, molecular mechanisms, and neuroimmunology. In addition, we discuss current research strategies designed to facilitate translational research and maximize the yield of precious resources (e.g. the Autism Tissue Program), highlight barriers to research, and consider future trends.

Factors associated with age of diagnosis among children with autism spectrum disorders

OBJECTIVE

Early diagnosis of children with autism spectrum disorders (ASD) is critical but often delayed until school age. Few studies have identified factors that may delay diagnosis. This study attempted to identify these factors among a community sample of children with ASD.

METHODS

Survey data were collected in Pennsylvania from 969 caregivers of children who had ASD and were younger than 21 years regarding their service experiences. Linear regression was used to identify clinical and demographic characteristics associated with age of diagnosis.

RESULTS

The average age of diagnosis was 3.1 years for children with autistic disorder, 3.9 years for pervasive developmental disorder not otherwise specified, and 7.2 years for Asperger's disorder. The average age of diagnosis increased 0.2 years for each year of age. Rural children received a diagnosis 0.4 years later than urban children. Near-poor children received a diagnosis 0.9 years later than those with incomes >100% above the poverty level. Children with severe language deficits received a diagnosis an average of 1.2 years earlier than other children. Hand flapping, toe walking, and sustained odd play were associated with a decrease in the age of diagnosis, whereas oversensitivity to pain and hearing impairment were associated with an increase. Children who had 4 or more primary care physicians before diagnosis received a diagnosis 0.5 years later than other children, whereas those whose pediatricians referred them to a specialist received a diagnosis 0.3 years sooner.

CONCLUSION

These findings suggest improvements over time in decreasing the age at which children with ASD, especially higher functioning children, receive a diagnosis. They also suggest a lack of resources in rural areas and for near-poor families and the importance of continuous pediatric care and specialty referrals. That only certain ASD-related behaviors, some of which are not required to satisfy diagnostic criteria, decreased the age of diagnosis suggests the importance of continued physician education.

Measuring autistic traits: heritability, reliability and validity of the Social and Communication Disorders Checklist

BACKGROUND

Autistic traits are widely distributed in the general population, but the boundaries of the autistic spectrum are unclear. Whole-population surveys of unselected samples of children are hampered by the lack of appropriate screening instruments.

AIMS

To assess whether the Social and Communication Disorders Checklist (SCDC) fulfils the need for a sensitive measure of autistic traits, which can be completed in a few minutes and which measures heritable characteristics in both males and females.

METHOD

A12-item scale, the SCDC, was completed by three independent samples drawn from a twin register, a group with Turner syndrome and children with a diagnosis of autistic-spectrum disorder attending clinics. The data were used to establish the heritability, reliability and validity of the checklist.

RESULTS

Traits measured by the SCDC were highly heritable in both genders (0.74). Internal consistency was excellent (0.93) and test - retest reliability high (0.81). Discriminant validity between pervasive developmental disorder and other clinical groups was good, discrimination from non-clinical samples was better; sensitivity (0.90), specificity (0.69).

CONCLUSIONS

The SCDC is a unique and efficient first-level screening questionnaire for autistic traits.

Immunity, neuroglia and neuroinflammation in autism

Autism is a complex neurodevelopmental disorder of early onset that is highly variable in its clinical presentation. Although the causes of autism in most patients remain unknown, several lines of research support the view that both genetic and environmental factors influence the development of abnormal cortical circuitry that underlies autistic cognitive processes and behaviors. The role of the immune system in the development of autism is controversial. Several studies showing peripheral immune abnormalities support immune hypotheses, however until recently there have been no immune findings in the CNS. We recently demonstrated the presence of neuroglial and innate neuroimmune system activation in brain tissue and cerebrospinal fluid of patients with autism, findings that support the view that neuroimmune abnormalities occur in the brain of autistic patients and may contribute to the diversity of the autistic phenotypes. The role of neuroglial activation and neuroinflammation are still uncertain but could be critical in maintaining, if not also in initiating, some of the CNS abnormalities present in autism. A better understanding of the role of neuroinflammation in the pathogenesis of autism may have important clinical and therapeutic implications.

Factors associated with age of diagnosis among children with autism spectrum disorders

OBJECTIVE

Early diagnosis of children with autism spectrum disorders (ASD) is critical but often delayed until school age. Few studies have identified factors that may delay diagnosis. This study attempted to identify these factors among a community sample of children with ASD.

METHODS

Survey data were collected in Pennsylvania from 969 caregivers of children who had ASD and were younger than 21 years regarding their service experiences. Linear regression was used to identify clinical and demographic characteristics associated with age of diagnosis.

RESULTS

The average age of diagnosis was 3.1 years for children with autistic disorder, 3.9 years for pervasive developmental disorder not otherwise specified, and 7.2 years for Asperger's disorder. The average age of diagnosis increased 0.2 years for each year of age. Rural children received a diagnosis 0.4 years later than urban children. Near-poor children received a diagnosis 0.9 years later than those with incomes >100% above the poverty level. Children with severe language deficits received a diagnosis an average of 1.2 years earlier than other children. Hand flapping, toe walking, and sustained odd play were associated with a decrease in the age of diagnosis, whereas oversensitivity to pain and hearing impairment were associated with an increase. Children who had 4 or more primary care physicians before diagnosis received a diagnosis 0.5 years later than other children, whereas those whose pediatricians referred them to a specialist received a diagnosis 0.3 years sooner.

CONCLUSION

These findings suggest improvements over time in decreasing the age at which children with ASD, especially higher functioning children, receive a diagnosis. They also suggest a lack of resources in rural areas and for near-poor families and the importance of continuous pediatric care and specialty referrals. That only certain ASD-related behaviors, some of which are not required to satisfy diagnostic criteria, decreased the age of diagnosis suggests the importance of continued physician education.

High levels of homocysteine and low serum paraoxonase 1 arylesterase activity in children with autism

Autism is a behaviorally defined disorder of unknown etiology that is thought to be influenced by genetic and environmental factors. High levels of homocysteine and oxidative stress are generally associated with neuropsychiatric disorders. The purpose of this study was to compare the level of homocysteine and other biomarkers in children with autism to corresponding values in age-matched healthy children. We measured total homocysteine (tHcy), vitamin B(12), paraoxonase and arylesterase activities of human paraoxonase 1 (PON1) in plasma and glutathione peroxidase (GPx) activity in erythrocytes from 21 children: 12 with autism (age: 8.29 +/- 2.76 years) and 9 controls (age: 8.33 +/- 1.82 years). We found statistically significant differences in tHcy levels and in arylesterase activity of PON1 in children with autism compared to the control group: 9.83 +/- 2.75 vs. 7.51 +/- 0.93 micromol/L (P < or =0.01) and 72.57 +/- 11.73 vs. 81.83 +/- 7.39 kU/L (P < or =0.005). In the autistic group there was a strong negative correlation between tHcy and GPx activity and the vitamin B(12) level was low or suboptimal. In conclusion, our study shows that in children with autism there are higher levels of tHcy, which is negatively correlated with GPx activity, low PON1 arylesterase activity and suboptimal levels of vitamin B(12).

Analysis of four DLX homeobox genes in autistic probands

BACKGROUND

Linkage studies in autism have identified susceptibility loci on chromosomes 2q and 7q, regions containing the DLX1/2 and DLX5/6 bigene clusters. The DLX genes encode homeodomain transcription factors that control craniofacial patterning and differentiation and survival of forebrain inhibitory neurons. We investigated the role that sequence variants in DLX genes play in autism by in-depth resequencing of these genes in 161 autism probands from the AGRE collection.

RESULTS

Sequencing of exons, exon/intron boundaries and known enhancers of DLX1, 2, 5 and 6 identified several nonsynonymous variants in DLX2 and DLX5 and a variant in a DLX5/6 intragenic enhancer. The nonsynonymous variants were detected in 4 of 95 families from which samples were sequenced. Two of these four SNPs were not observed in 378 undiagnosed samples from North American populations, while the remaining 2 were seen in one sample each.

CONCLUSION

Segregation of these variants in pedigrees did not generally support a contribution to autism susceptibility by these genes, although functional analyses may provide insight into the biological understanding of these important proteins.

Access and service use by children with autism spectrum disorders in Medicaid Managed Care

Although Medicaid is the largest public payer of behavioral health services, information on access and utilization of services is lacking, and no data on the frequency of service use or types of services provided for children with autism spectrum disorders (ASDs) are available. As states move toward managed care approaches for their Medicaid program, services information is critical. Behavioral health service data for children with autism spectrum disorders were collected from a state Medicaid Managed Care (MMC) program and analyzed from fiscal years 1995 through 2000. Findings revealed that the number of children who received services over time increased significantly; however, the rate of service use was only one tenth of what should be expected based on prevalence rates. The mean number of service days provided per child decreased significantly, about 40%, and the most prevalent forms of treatment changed. Day treatment vanished and medication and case management increased disproportionately to the number of children served. Explanations and implications of the findings are presented as well as recommendations for future research.

Identification of significant association and gene-gene interaction of GABA receptor subunit genes in autism

Autism is a common neurodevelopmental disorder with a significant genetic component. Existing research suggests that multiple genes contribute to autism and that epigenetic effects or gene-gene interactions are likely contributors to autism risk. However, these effects have not yet been identified. Gamma-aminobutyric acid (GABA), the primary inhibitory neurotransmitter in the adult brain, has been implicated in autism etiology. Fourteen known autosomal GABA receptor subunit genes were studied to look for the genes associated with autism and their possible interactions. Single-nucleotide polymorphisms (SNPs) were screened in the following genes: GABRG1, GABRA2, GABRA4, and GABRB1 on chromosome 4p12; GABRB2, GABRA6, GABRA1, GABRG2, and GABRP on 5q34-q35.1; GABRR1 and GABRR2 on 6q15; and GABRA5, GABRB3, and GABRG3 on 15q12. Intronic and/or silent mutation SNPs within each gene were analyzed in 470 white families with autism. Initially, SNPs were used in a family-based study for allelic association analysis--with the pedigree disequilibrium test and the family-based association test--and for genotypic and haplotypic association analysis--with the genotype-pedigree disequilibrium test (geno-PDT), the association in the presence of linkage (APL) test, and the haplotype family-based association test. Next, with the use of five refined independent marker sets, extended multifactor-dimensionality reduction (EMDR) analysis was employed to identify the models with locus joint effects, and interaction was further verified by conditional logistic regression. Significant allelic association was found for markers RS1912960 (in GABRA4; P = .01) and HCV9866022 (in GABRR2; P = .04). The geno-PDT found significant genotypic association for HCV8262334 (in GABRA2), RS1912960 and RS2280073 (in GABRA4), and RS2617503 and RS12187676 (in GABRB2). Consistent with the allelic and genotypic association results, EMDR confirmed the main effect at RS1912960 (in GABRA4). EMDR also identified a significant two-locus gene-gene effect model involving RS1912960 in GABRA4 and RS2351299 in GABRB1. Further support for this two-locus model came from both the multilocus geno-PDT and the APL test, which indicated a common genotype and haplotype combination positively associated with disease. Finally, these results were also consistent with the results from the conditional logistic regression, which confirmed the interaction between GABRA4 and GABRB1 (odds ratio = 2.9 for interaction term; P = .002). Through the convergence of all analyses, we conclude that GABRA4 is involved in the etiology of autism and potentially increases autism risk through interaction with GABRB1. These results support the hypothesis that GABA receptor subunit genes are involved in autism, most likely via complex gene-gene interactions.

The genetic relationship between individual differences in social and nonsocial behaviours characteristic of autism

Two types of behaviours shown in children - those reflecting social impairment and nonsocial obsessive repetitive behaviours - are central to defining and diagnosing autism spectrum disorders (ASDs). Parent and teacher data on social and nonsocial behaviours were obtained from a community sample of >3000 7-year-old twin pairs. Social and nonsocial behaviours were only modestly correlated, and it was found that some individuals had extreme scores on either social or nonsocial scales but not both. Genetic model-fitting showed that social and nonsocial behaviours are both highly heritable, but their genetic overlap is modest, with most of the genetic influence being specific to either social or nonsocial behaviours. Considering these behaviours separately might help clarify gene-brain-behaviour pathways in future research.

Quantitative genome scan and Ordered-Subsets Analysis of autism endophenotypes support language QTLs

Autism is a neurodevelopmental syndrome with early childhood onset and deficits in three behavioral and cognitive dimensions: language, social skills and repetitive or restrictive behaviors. We hypothesized that using these endophenotypes would provide more power to detect linkage than the diagnosis of autism. Previously, we reported results for a nonparametric quantitative trait locus (QTL) genome scan in 152 families with autism, which revealed a linkage peak related to spoken language on 7q35. Here, we present the results of a nonparametric QTL scan of autism endophenotypes in 291 multiplex families, including the original 152. The strongest evidence for an 'age at first word' QTL was on chromosomes 3q at 147 cM (Z=3.10, P<0.001), and 17q at 93 cM (Z=2.84, P=0.002), both represent novel susceptibility loci for autism endophenotypes. There was also support for a previously identified autism peak on chromosome 17 at 43 cM (Z=2.22, P=0.013) with 'age at first phrase'. The 7q35 language peak was attenuated (Z=2.05, P=0.02) compared with the original finding. To explore the possibility of increased heterogeneity resulting from the addition of 135 families to the sample, we conducted an Ordered-Subsets Analysis on chromosome 7; these results suggest that the 132 autism families with the earliest average age at first word are responsible for the QTL on 7q35. This locus on 7q35 may harbor a gene contributing variability in spoken language that is not uniquely related to language delay in autism.

Autism-Spectrum Quotient-Japanese version and its short forms for screening normally intelligent persons with pervasive developmental disorders

A Japanese version of the Autism Spectrum Quotient (AQ), AQ-J was administered to 25 normally intelligent high-functioning pervasive developmental disorder (HPDD) patients (mean age, 24.2 years; 24 male, one female) and 215 controls (mean age, 30.4 years; 86 male, 129 female) randomly selected from the general population. The AQ-J had satisfactory internal consistency reliability (Cronbach's alpha > 0.70 in the two groups), test-retest reliability, and discriminant validity [i.e. the AQ-J score was significantly higher in the HPDD (mean, 29.6) than controls (mean, 22.2)]. At a cut-off of 26, the AQ-J had satisfactory sensitivity, specificity, and negative predictive value, but it had low positive predictive value (0.24) possibly due to the facts that the 25 mild HPDD patients scored lower and the controls scored higher on the AQ-J than British counterparts on the AQ. The AQ-J-21 (consisting of 21 items significantly associated with HPDD diagnosis) and the AQ-J-10 (consisting of 10 of the 21 items with an effect size > 0.17) had higher, although not satisfactory, positive predictive values of 0.35 and 0.46 at cut-offs of 12 and 7, respectively, than the AQ-J. The AQ-J and two short forms are useful not to predict but to rule out mild HPDD, the most difficult part of HPDD to be distinguished from non-PDD conditions, in persons scoring under the cut-offs and to consider professionals' examination of HPDD in persons scoring over them, because their negative predictive values were satisfactory.

Asperger Syndrome in Children

PURPOSE

To review Asperger syndrome characteristics, assessment tools, interventions, outcomes, and the role of the nurse practitioner in diagnosing and caring for children with Asperger syndrome.

DATA SOURCES

Review of published literature on and diagnostic criteria of the condition.

CONCLUSIONS

Asperger syndrome is a pervasive developmental disorder or an autism spectrum disorder that is thought to have an incidence higher than that of autism. Asperger syndrome is different from autism, with a lack of delayed language as the most distinct difference between Asperger syndrome and autism.

IMPLICATIONS FOR PRACTICE

Because of the importance of early diagnosis of Asperger syndrome for outcome improvement, screening at all well-child visits from infancy on is of utmost importance to primary care pediatric nurse practitioners. With early diagnosis, timely intervention is possible, which is proven to show improvement in outcomes.

Allelic heterogeneity at the serotonin transporter locus (SLC6A4) confers susceptibility to autism and rigid-compulsive behaviors

Autism is a spectrum of neurodevelopmental disorders with a primarily genetic etiology exhibiting deficits in (1) development of language and (2) social relationships and (3) patterns of repetitive, restricted behaviors or interests and resistance to change. Elevated platelet serotonin (5-HT) in 20%-25% of cases and efficacy of selective 5-HT reuptake inhibitors (SSRIs) in treating anxiety, depression, and repetitive behaviors points to the 5-HT transporter (5-HTT; SERT) as a strong candidate gene. Association studies involving the functional insertion/deletion polymorphism in the promoter (5-HTTLPR) and a polymorphism in intron 2 are inconclusive, possibly because of phenotypic heterogeneity. Nonetheless, mounting evidence for genetic linkage of autism to the chromosome 17q11.2 region that harbors the SERT locus (SLC6A4) supports a genetic effect at or near this gene. We confirm recent reports of sex-biased genetic effects in 17q by showing highly significant linkage driven by families with only affected males. Association with common alleles fails to explain observed linkage; therefore, we hypothesized that preferential transmission of multiple alleles does explain it. From 120 families, most contributing to linkage at 17q11.2, we found four coding substitutions at highly conserved positions and 15 other variants in 5' noncoding and other intronic regions transmitted in families exhibiting increased rigid-compulsive behaviors. In the aggregate, these variants show significant linkage to and association with autism. Our data provide strong support for a collection of multiple, often rare, alleles at SLC6A4 as imposing risk of autism.

The potential importance of steroids in the treatment of autistic spectrum disorders and other disorders involving mercury toxicity

Autism is a neurodevelopmental disorder that according to the Centers for Disease Control and Prevention (CDC) affects 1 in 150 children in the United States. Autism is characterized by impairments in social relatedness and communication, repetitive behaviors, abnormal movements, and sensory dysfunction. Recently emerging evidence suggests that mercury, especially from childhood vaccines, appears to be a factor in the development of the autistic disorders, and that autistic children have higher than normal body-burdens of mercury. In considering mercury toxicity, it has previously been shown that testosterone significantly potentates mercury toxicity, whereas estrogen is protective. Examination of autistic children has shown that the severity of autistic disorders correlates with the amount of testosterone present in the amniotic fluid, and an examination of a case-series of autistic children has shown that some have plasma testosterone levels that were significantly elevated in comparison neurotypical control children. A review of some of the current biomedical therapies for autistics, such as glutathione and cysteine, chelation, secretin, and growth hormone, suggests that they may in fact lower testosterone levels. We put forward the medical hypothesis that autistic disorders, in fact, represents a form of testosterone mercury toxicity, and based upon this observation, one can design novel treatments for autistics directed towards higher testosterone levels in autistic children. We suggest a series of experiments that need to be conducted in order to evaluate the exact mechanisms for mercury-testosterone toxicity, and various types of clinical manipulations that may be employed to control testosterone levels. It is hoped by devising therapies that address the steroid hormone pathways, in addition to the current treatments that successful lower heavy metal body-burdens of mercury, will work synergistically to improve clinical outcomes. In light of the fact that there are a number of other diseases that may have a chronic mercury toxicity component, such as Alzheimer's disease, heart disease, obesity, ALS, asthma, and other various forms of autoimmune disorders, it is imperative that further research should be conducted to understand mercury-testosterone toxicity.

US Department of Education data on "autism" are not reliable for tracking autism prevalence

Many autism advocacy groups use the data collected by the US Department of Education (USDE) to show a rapidly increasing prevalence of autism. Closer examination of these data to follow each birth-year cohort reveals anomalies within the USDE data on autism. The USDE data show not only a rise in overall autism prevalence with time but also a significant and nearly linear rise in autism prevalence within a birth-year cohort as it ages, with significant numbers of new cases as late as 17 years of age. In addition, an unexpected reduction in the rise of autism prevalence occurs in most cohorts at 12 years of age, the age when most children would be entering middle school. These anomalies point to internal problems in the USDE data that make them unsuitable for tracking autism prevalence.

A comparison of intensive behavior analytic and eclectic treatments for young children with autism

We compared the effects of three treatment approaches on preschool-age children with autism spectrum disorders. Twenty-nine children received intensive behavior analytic intervention (IBT; 1:1 adult:child ratio, 25-40 h per week). A comparison group (n=16) received intensive "eclectic" intervention (a combination of methods, 1:1 or 1:2 ratio, 30 h per week) in public special education classrooms (designated the AP group). A second comparison group (GP) comprised 16 children in non-intensive public early intervention programs (a combination of methods, small groups, 15 h per week). Independent examiners administered standardized tests of cognitive, language, and adaptive skills to children in all three groups at intake and about 14 months after treatment began. The groups were similar on key variables at intake. At follow-up, the IBT group had higher mean standard scores in all skill domains than the AP and GP groups. The differences were statistically significant for all domains except motor skills. There were no statistically significant differences between the mean scores of the AP and GP groups. Learning rates at follow-up were also substantially higher for children in the IBT group than for either of the other two groups. These findings are consistent with other research showing that IBT is considerably more efficacious than "eclectic" intervention.

Public health research at the CDC: implications for communication sciences and disorders

The following paper provides an overview of public health research at the Centers for Disease Control and Prevention (CDC), with emphasis on research involving speech, language and hearing disorders. Public health research involves a sequence of activities from disease tracking to disease prevention. Public health focuses on populations and works to identify changes in programs and policies that can positively impact population health. This paper uses three recent studies conducted by CDC investigators to illustrate different types of research along the public health prevention continuum, with emphasis on activities involving speech, language, and hearing endpoints. The three examples are: a study of cochlear implants and the subsequent risk of meningitis (illustrative of a public health response); a study examining the prevalence of autism in several U.S. populations (an example of a surveillance or monitoring activity); and a study examining the role of in utero cigarette exposure in the etiology of oral facial clefts (illustrative of a epidemiologic risk factor study). The public health continuum provides an important vehicle for advancing our knowledge of the causes and effective prevention of communication disorders.

LEARNING OUTCOMES

The reader will become familiar with the public health sequence and the manners in which public health research relates to speech, language, and hearing disorders. The reader will be able to identify and discriminate among the components of public health research using the examples provided.

Characteristics of Children with Autistic Spectrum Disorders Served in Comprehensive Community-based Mental Health Settings

This study describes the characteristics of children with autistic spectrum disorders (ASD) receiving treatment in community mental health settings. Data from a national community mental health initiative was used to identify children who had received a primary diagnosis of ASD. These children were compared with children with other diagnoses on socio-demographic and psychosocial characteristics, presenting problems and service histories. Regardless of diagnosis, children were most often referred to service because of disruptive behaviors. Children with ASD were less likely to be referred for drug use, truancy or running away, but were more likely to be referred for social interaction difficulties and strange behavior. Many children had family histories of mental illness, substance abuse and domestic violence. Implications of these findings are discussed in detail.

Analysis of the RELN gene as a genetic risk factor for autism

Several genome-wide screens have indicated the presence of an autism susceptibility locus within the distal long arm of chromosome 7 (7q). Mapping at 7q22 within this region is the candidate gene reelin (RELN). RELN encodes a signaling protein that plays a pivotal role in the migration of several neuronal cell types and in the development of neural connections. Given these neurodevelopmental functions, recent reports that RELN influences genetic risk for autism are of significant interest. The total data set consists of 218 Caucasian families collected by our group, 85 Caucasian families collected by AGRE, and 68 Caucasian families collected at Tufts University were tested for genetic association of RELN variants to autism. Markers included five single-nucleotide polymorphisms (SNPs) and a repeat in the 5'-untranslated region (5'-UTR). Tests for association in Duke and AGRE families were also performed on four additional SNPs in the genes PSMC2 and ORC5L, which flank RELN. Family-based association analyses (PDT, Geno-PDT, and FBAT) were used to test for association of single-locus markers and multilocus haplotypes with autism. The most significant association identified from this combined data set was for the 5'-UTR repeat (PDT P-value=0.002). These analyses show the potential of RELN as an important contributor to genetic risk in autism.

Replication of autism linkage: fine-mapping peak at 17q21

Autism is a heritable but genetically complex disorder characterized by deficits in language and in reciprocal social interactions, combined with repetitive and stereotypic behaviors. As with many genetically complex disorders, numerous genome scans reveal inconsistent results. A genome scan of 345 families from the Autism Genetic Resource Exchange (AGRE) (AGRE_1), gave the strongest evidence of linkage at 17q11-17q21 in families with no affected females. Here, we report a full-genome scan of an independent sample of 91 AGRE families with 109 affected sibling pairs (AGRE_2) that also shows the strongest evidence of linkage to 17q11-17q21 in families with no affected females. Taken together, these samples provide a replication of linkage to this chromosome region that is, to our knowledge, the first such replication in autism. Fine mapping at 2-centimorgan (cM) intervals in the combined sample of families with no affected females reveals a linkage peak at 66.85 cM, which places this locus at 17q21.

The role of nurses in screening for autistic spectrum disorder in pediatric primary care

This article addresses the issue of integration of routine screening for autism spectrum disorder (ASD) in pediatric primary care. The relationship between screening and patient outcome is discussed. The ASD screening recommendations of the American Academy of Pediatrics and practical issues associated with their application are then reviewed. Finally, data from a pilot project to prepare nurses to conduct ASD screening during routine pediatric health visits are presented. The authors discuss the role of nurses in establishing systems within pediatric primary care to identify and refer children at risk for ASD.

Risk factors for autism: perinatal factors, parental psychiatric history, and socioeconomic status

Research suggests that heredity and early fetal development play a causal role in autism. This case-control study explored the association between perinatal factors, parental psychiatric history, socioeconomic status, and risk of autism. The study was nested within a cohort of all children born in Denmark after 1972 and at risk of being diagnosed with autism until December 1999. Prospectively recorded data were obtained from nationwide registries in Denmark. Cases totaled 698 children with a diagnosis of autism; each case was individually matched by gender, birth year, and age to 25 controls. Analyses by conditional logistic regression produced risk ratios and 95% confidence intervals. Adjusted analyses showed that the risk of autism was associated with breech presentation (risk ratio (RR) = 1.63, 95% confidence interval (CI): 1.18, 2.26), low Apgar score at 5 minutes (RR = 1.89, 95% CI: 1.10, 3.27), gestational age at birth <35 weeks (RR = 2.45, 95% CI: 1.55, 3.86), and parental psychiatric history (schizophrenia-like psychosis: RR = 3.44, 95% CI: 1.48, 7.95; affective disorder: RR = 2.91, 95% CI: 1.65, 5.14). Analyses showed no statistically significant association between risk of autism and weight for gestational age, parity, number of antenatal visits, parental age, or socioeconomic status. Results suggest that prenatal environmental factors and parental psychopathology are associated with the risk of autism. These factors seem to act independently.

Autistic disorder and viral infections

Autistic disorder (autism) is a behaviorally defined developmental disorder with a wide range of behaviors. Although the etiology of autism is unknown, data suggest that autism results from multiple etiologies with both genetic and environmental contributions, which may explain the spectrum of behaviors seen in this disorder. One proposed etiology for autism is viral infection very early in development. The mechanism, by which viral infection may lead to autism, be it through direct infection of the central nervous system (CNS), through infection elsewhere in the body acting as a trigger for disease in the CNS, through alteration of the immune response of the mother or offspring, or through a combination of these, is not yet known. Animal models in which early viral infection results in behavioral changes later in life include the influenza virus model in pregnant mice and the Borna disease virus model in newborn Lewis rats. Many studies over the years have presented evidence both for and against the association of autism with various viral infections. The best association to date has been made between congenital rubella and autism; however, members of the herpes virus family may also have a role in autism. Recently, controversy has arisen as to the involvement of measles virus and/or the measles, mumps, rubella (MMR) vaccine in the development of autism. Biological assays lend support to the association between measles virus or MMR and autism whereas epidemiologic studies show no association between MMR and autism. Further research is needed to clarify both the mechanisms whereby viral infection early in development may lead to autism and the possible involvement of the MMR vaccine in the development of autism.

Identifying environmental contributions to autism: provocative clues and false leads

The potential role of environmental factors in autism spectrum disorders (ASD) is an area of emerging interest within the public and scientific communities. The high degree of heritability of ASD suggests that environmental influences are likely to operate through their interaction with genetic susceptibility during vulnerable periods of development. Evaluation of the plausibility of specific neurotoxicants as etiological agents in ASD should be guided by toxicological principles, including dose-effect dependency and pharmacokinetic parameters. Clinical and epidemiological investigations require the use of sufficiently powered study designs with appropriate control groups and unbiased case ascertainment and exposure assessment. Although much of the existing data that have been used to implicate environmental agents in ASD are limited by methodological shortcomings, a number of efforts are underway that will allow more rigorous evaluation of the role of environmental exposures in the etiology and/or phenotypic expression of the disorder. Surveillance systems are now in place that will provide reliable prevalence estimates going forward in time. Anticipated discoveries in genetics, brain pathology, and the molecular/cellular basis of functional impairment in ASD are likely to provide new opportunities to explore environmental aspects of this disorder.

Confirmation of the association of the C4B null allelle in autism

The objective of this study was to examine and attempt to confirm our previous findings of an increased frequency of the C4B null allele (C4BQ0) in subjects with autism. Newly identified subjects from Utah and Oregon were studied. Families evaluated included 85 who had a child with autism and 69 control families. Of the subjects with autism studied, 42.4% carried at least one C4BQ0, compared with 14.5% of the control subjects (p = 0.00013), with a relative risk of 4.33. Over half of the C4B null alleles in the subjects with autism involved C4A duplications. A marked increase in the ancestral haplotype 44.1 that lacks a C4B gene and has 2 C4A genes was also observed. The results of this study suggest that the human leukocyte antigen class III C4BQ0 significantly increases the risk for autism.

Neuroglial activation and neuroinflammation in the brain of patients with autism

Autism is a neurodevelopmental disorder characterized by impaired communication and social interaction and may be accompanied by mental retardation and epilepsy. Its cause remains unknown, despite evidence that genetic, environmental, and immunological factors may play a role in its pathogenesis. To investigate whether immune-mediated mechanisms are involved in the pathogenesis of autism, we used immunocytochemistry, cytokine protein arrays, and enzyme-linked immunosorbent assays to study brain tissues and cerebrospinal fluid (CSF) from autistic patients and determined the magnitude of neuroglial and inflammatory reactions and their cytokine expression profiles. Brain tissues from cerebellum, midfrontal, and cingulate gyrus obtained at autopsy from 11 patients with autism were used for morphological studies. Fresh-frozen tissues available from seven patients and CSF from six living autistic patients were used for cytokine protein profiling. We demonstrate an active neuroinflammatory process in the cerebral cortex, white matter, and notably in cerebellum of autistic patients. Immunocytochemical studies showed marked activation of microglia and astroglia, and cytokine profiling indicated that macrophage chemoattractant protein (MCP)-1 and tumor growth factor-beta1, derived from neuroglia, were the most prevalent cytokines in brain tissues. CSF showed a unique proinflammatory profile of cytokines, including a marked increase in MCP-1. Our findings indicate that innate neuroimmune reactions play a pathogenic role in an undefined proportion of autistic patients, suggesting that future therapies might involve modifying neuroglial responses in the brain.

Protecting children from environmental toxins

Lanphear and colleagues argue that the existing requirements in the US for toxicity testing and regulation of pesticides and industrial chemicals are inadequate to safeguard children

National autism prevalence trends from United States special education data

OBJECTIVE

Reports of large increases in autism prevalence have been a matter of great concern to clinicians, educators, and parents. This analysis uses a national data source to compare the prevalence of autism with that of other disabilities among successive birth cohorts of US school-aged children.

DESIGN

Comparison of birth cohort curves constructed from administrative data.

SETTING AND POPULATION

US children 6 to 17 years of age between 1992 and 2001.

MAIN OUTCOME MEASURES

A disability category classification of autism, mental retardation, speech and language impairment, traumatic brain injury, or other health impairment, as documented by state departments of education and reported to the Office of Special Education Programs, US Department of Education.

RESULTS

Prevalences of disability category classifications for annual birth cohorts from 1975 to 1995 were calculated by using denominators from US Census Bureau estimates. For the autism classification, there were birth cohort differences, with prevalences increasing among successive (younger) cohorts. The increases were greatest for annual cohorts born from 1987 to 1992. For cohorts born after 1992, the prevalence increased with each successive year but the increases did not appear to be as great, although there were fewer data points available within cohorts. No concomitant decreases in categories of mental retardation or speech/language impairment were seen. Curves for other health impairments, the category including children with attention-deficit/hyperactivity disorder, also showed strong cohort differences.

CONCLUSIONS

Cohort curves suggest that autism prevalence has been increasing with time, as evidenced by higher prevalences among younger birth cohorts. The narrowing in vertical separation of the cohort curves in recent years may mark a slowing in the autism prevalence increase.

School district resources and identification of children with autistic disorder

OBJECTIVES

We estimated the effect of community and school district resources on the identification of children with autistic disorder.

METHODS

Latent growth curve regression models were applied to school district-level data from one large state.

RESULTS

The rate of identification of autistic disorder increased on average by 1.0 child per 10000 per year (P<.001), with statistically significant district variation. After adjustment for district and community characteristics, each increase in decile of school revenue was associated with an increase of 0.16 per 10000 children identified with autistic disorder. The proportion of economically disadvantaged children per district was inversely associated with autistic disorder cases.

CONCLUSIONS

District revenue was associated with higher proportions of children identified with autistic disorder at baseline and increasing rates of identification when measured longitudinally. Economically disadvantaged communities may need assistance to identify children with autistic spectrum disorders and other developmental delays that require attention.

A mixed epigenetic/genetic model for oligogenic inheritance of autism with a limited role for UBE3A

The genetic contribution to autism is often attributed to the combined effects of many loci (ten or more). This conclusion is based in part on the much lower concordance for dizygotic (DZ) than for monozygotic (MZ) twins, and is consistent with the failure to find strong evidence for linkage in genome-wide studies. We propose that the twin data are compatible with oligogenic inheritance combined with a major, genetic or epigenetic, de novo component to the etiology. Based on evidence that maternal but not paternal duplications of chromosome 15q cause autism, we attempted to test the hypothesis that autism involves oligogenic inheritance (two or more loci) and that the Angelman gene (UBE3A), which encodes the E6-AP ubiquitin ligase, is one of the contributing genes. A search for epigenetic abnormalities led to the discovery of a tissue-specific differentially methylated region (DMR) downstream of the UBE3A coding exons, but the region was not abnormal in autism lymphoblasts or brain samples. Based on evidence for allele sharing in 15q among sib-pairs, abnormal DNA methylation at the 5'-CpG island of UBE3A in one of 17 autism brains, and decreased E6-AP protein in some autism brains, we propose a mixed epigenetic and genetic model for autism with both de novo and inherited contributions. The role of UBE3A may be quantitatively modest, but interacting proteins such as those ubiquitinated by UBE3A may be candidates for a larger role in an oligogenic model. A mixed epigenetic and genetic and mixed de novo and inherited (MEGDI) model could be relevant to other "complex disease traits".

Intervention, treatmentand care in autistic disorder. Challenging case reports from northern Finland

OBJECTIVES

Autism produces characteristic patterns of behaviour, and individuals with autistic disorder (AD) have a lot in common in terms of behaviour and mannerisms. Individuals with autism, however, also have their own overall personalities, which both underlie and interact with their autism. This article focuses on challenges of identifying AD and delivering appropriate services in face of long distances and limited resources.

STUDY DESIGN

This study is a retrospective descriptive chart review and cases series. Hospital records and data on the treatment/habilitation status of 187 children and adolescents with autistic disorder aged 3-18 years were evaluated from Northern Finland.

METHODS

Nine subjects, representing the age group of 9- to 17-year-olds, did not show any improvement on the Childhood Autism Rating Scale (CARS) and in the clinical examination during the follow-up period 1990--97. In this study, these children and adolescents with AD were evaluated more carefully.

RESULTS

The treatment programs and therapies varied, depending on the availability of trained staff. There were various reasons for the absence of the most suitable treatment, or habilitation, at the individual level. The difficulties also varied over time and between individuals. In addition, after the follow-up period, four of the nine (55.6%) individuals showed more positive outcome when the level of autism had been taken into account in the planning of the intervention for, treatment and care of AD.

CONCLUSION

The possible reasons for poor outcome included the level of mental disability, impairments of speech and communication, lack of knowledge of autism at the municipal level, long distance to services, severe epilepsy, additional medical diagnosis, parental acceptance of the child's autism and late start of the intervention for, or habilitation of autism.

Neonatal hyperbilirubinemia and risk of autism spectrum disorders

OBJECTIVE

To investigate the association between neonatal hyperbilirubinemia and autism spectrum disorders (ASD).

METHODS

We conducted a large case-control study nested within the cohort of singleton term infants born between 1995 and 1998 at a northern California Kaiser Permanente hospital. Case subjects (n = 338) were children with an ASD diagnosis recorded in Kaiser Permanente outpatient databases; control subjects (n = 1817) were children without an ASD diagnosis, who were randomly sampled and frequency-matched to case subjects according to gender, birth year, and birth hospital.

RESULTS

Approximately 28% of case and control subjects received > or =1 bilirubin test in the first 30 days of life. No case-control differences were observed for maximal bilirubin levels of > or =15 mg/dL (10.1% vs 12.1%), > or =20 mg/dL (2.1% vs 2.5%), or > or =25 mg/dL (0.3% vs 0.2%). Compared with children whose maximal neonatal bilirubin levels were <15 mg/dL or not measured, children with any degree of bilirubin level elevation were not at increased risk of ASD, after adjustment for gender, birth facility, maternal age, maternal race/ethnicity, maternal education, and gestational age (for bilirubin levels of 15-19.9 mg/dL: odds ratio: 0.7; 95% confidence interval: 0.5-1.2; for bilirubin levels of 20-24.9 mg/dL: odds ratio: 0.7; 95% confidence interval: 0.3-1.6; for bilirubin levels of > or =25 mg/dL: odds ratio: 1.1; 95% confidence interval: 0.1-11.2).

CONCLUSION

These data suggest that neonatal hyperbilirubinemia is not a risk factor for ASD.

Genome-wide and Ordered-Subset linkage analyses provide support for autism loci on 17q and 19p with evidence of phenotypic and interlocus genetic correlates

BACKGROUND

Autism is a neurobehavioral spectrum of phenotypes characterized by deficits in the development of language and social relationships and patterns of repetitive, rigid and compulsive behaviors. Twin and family studies point to a significant genetic etiology, and several groups have performed genomic linkage screens to identify susceptibility loci.

METHODS

We performed a genome-wide linkage screen in 158 combined Tufts, Vanderbilt and AGRE (Autism Genetics Research Exchange) multiplex autism families using parametric and nonparametric methods with a categorical autism diagnosis to identify loci of main effect. Hypothesizing interdependence of genetic risk factors prompted us to perform exploratory studies applying the Ordered-Subset Analysis (OSA) approach using LOD scores as the trait covariate for ranking families. We employed OSA to test for interlocus correlations between loci with LOD scores > or =1.5, and empirically determined significance of linkage in optimal OSA subsets using permutation testing. Exploring phenotypic correlates as the basis for linkage increases involved comparison of mean scores for quantitative trait-based subsets of autism between optimal subsets and the remaining families.

RESULTS

A genome-wide screen for autism loci identified the best evidence for linkage to 17q11.2 and 19p13, with maximum multipoint heterogeneity LOD scores of 2.9 and 2.6, respectively. Suggestive linkage (LOD scores > or =1.5) at other loci included 3p, 6q, 7q, 12p, and 16p. OSA revealed positive correlations of linkage between the 19p locus and 17q, between 19p and 6q, and between 7q and 5p. While potential phenotypic correlates for these findings were not identified for the chromosome 7/5 combination, differences indicating more rapid achievement of "developmental milestones" was apparent in the chromosome 19 OSA-defined subsets for 17q and 6q. OSA was used to test the hypothesis that 19p linkage involved more rapid achievement of these milestones and it revealed significantly increased LOD* scores at 19p13.

CONCLUSIONS

Our results further support 19p13 as harboring an autism susceptibility locus, confirm other linkage findings at 17q11.2, and demonstrate the need to analyze more discreet trait-based subsets of complex phenotypes to improve ability to detect genetic effects.

Macrocephaly, corpus callosum morphology, and autism

Although the cause of autism is undetermined, a general consensus has been that some type of early aberrant neural development underlies the disorder. Given the increased prevalence of macrocephaly in autism, one theory of abnormal neural development implicates early brain growth resulting in larger brain and head size in autism. Surface area measurements of the midsagittal section of the corpus callosum can be used as an index of neural development and white-matter integrity because the corpus callosum is the major white-matter structure that interconnects the two cerebral hemispheres. The purpose of this study was to obtain corpus callosum surface area, shape, and contour in a sample of non-mentally retarded autistic subjects with macrocephaly (n = 12) and compare them with those of matched (n = 8), typically developing control subjects with benign macrocephaly. No significant differences were found in surface area, shape, or contour between groups, nor did corpus callosum surface area relate to measures of IQ or picture vocabulary. These findings suggest no unique difference in overall regional corpus callosum surface area in autism with macrocephaly.