Autosomal dominant mannose-binding lectin deficiency is associated with worse neurodevelopmental outcomes after cardiac surgery in infants.

OBJECTIVES: The MBL2 gene is the major genetic determinant of mannose-binding lectin (MBL)-an acute phase reactant. Low MBL levels have been associated with adverse outcomes in preterm infants. The MBL2Gly54Asp missense variant causes autosomal dominant MBL deficiency. We tested the hypothesis that MBL2Gly54Asp is associated with worse neurodevelopmental outcomes after cardiac surgery in neonates. METHODS: This is an analysis of a previously described cohort of patients with nonsyndromic congenital heart disease who underwent cardiac surgery with cardiopulmonary bypass before age 6 months (n = 295). Four-year neurodevelopment was assessed in 3 domains: Full-Scale Intellectual Quotient, the Visual Motor Integration development test, and the Child Behavior Checklist to assess behavior problems. The Child Behavior Checklist measured total behavior problems, pervasive developmental problems, and internalizing/externalizing problems. A multivariable linear regression model, adjusting for confounders, was fit. RESULTS: MBL2Gly54Asp was associated with a significantly increased covariate-adjusted pervasive developmental problem score (ß = 3.98; P = .0025). Sensitivity analyses of the interaction between age at first surgery and MBL genotype suggested effect modification for the patients with MBL2Gly54Asp (Pinteraction = .039), with the poorest neurodevelopment outcomes occurring in children who had surgery earlier in life. CONCLUSIONS: We report the novel finding that carriers of MBL2Gly54Asp causing autosomal dominant MBL deficiency have increased childhood pervasive developmental problems after cardiac surgery, independent of other covariates. Sensitivity analyses suggest that this effect may be larger in children who underwent surgery at earlier ages. These data support the role of nonsyndromic genetic variation in determining postsurgical neurodevelopment-related outcomes in children with congenital heart disease.

[The possibility of prenatal diagnosis of autism spectrum disorder]. / Az autizmusspektrum-zavarok prenatális diagnózisának lehetoségei.

Autism spectrum disorder (ASD) is an idiopathic multifactorial disease. Chromosomal abnormalities could be found only in a few percent (0.3-0.6) of cases. The estimated prevalence is 0.6 in Europe and the prevalence of the disease has been increased in last few decades. ASD have an impact on the quality of life of the patient and his family. The early diagnosis of ASD is most important. There are limited data regarding the measure of biparietal diameter (BPD) of the fetus in the first trimester of pregnancy. These data suggested the BPD is an important screening marker for ASD, but the complex prenatal screening is unresolved. There is a need for further investigations of the genetic background of ASD and to identify potentially first trimester ultrasound markers for ASD.

Environmental chemical exposures and autism spectrum disorders: a review of the epidemiological evidence.

In the past decade, the number of epidemiological publications addressing environmental chemical exposures and autism has grown tremendously. These studies are important because it is now understood that environmental factors play a larger role in causing autism than previously thought and because they address modifiable risk factors that may open up avenues for the primary prevention of the disability associated with autism. In this review, we covered studies of autism and estimates of exposure to tobacco, air pollutants, volatile organic compounds and solvents, metals (from air, occupation, diet, dental amalgams, and thimerosal-containing vaccines), pesticides, and organic endocrine-disrupting compounds such as flame retardants, non-stick chemicals, phthalates, and bisphenol A. We included studies that had individual-level data on autism, exposure measures pertaining to pregnancy or the 1st year of life, valid comparison groups, control for confounders, and adequate sample sizes. Despite the inherent error in the measurement of many of these environmental exposures, which is likely to attenuate observed associations, some environmental exposures showed associations with autism, especially traffic-related air pollutants, some metals, and several pesticides, with suggestive trends for some volatile organic compounds (e.g., methylene chloride, trichloroethylene, and styrene) and phthalates. Whether any of these play a causal role requires further study. Given the limited scope of these publications, other environmental chemicals cannot be ruled out, but have not yet been adequately studied. Future research that addresses these and additional environmental chemicals, including their most common routes of exposures, with accurate exposure measurement pertaining to several developmental windows, is essential to guide efforts for the prevention of the neurodevelopmental damage that manifests in autism symptoms.

Early developmental trajectories associated with ASD in infants with tuberous sclerosis complex.

OBJECTIVE: We performed a longitudinal cohort study of infants with tuberous sclerosis complex (TSC), with the overarching goal of defining early clinical, behavioral, and biological markers of autism spectrum disorder (ASD) in this high-risk population. METHODS: Infants with TSC and typically developing controls were recruited as early as 3 months of age and followed longitudinally until 36 months of age. Data gathered at each time point included detailed seizure history, developmental testing using the Mullen Scales of Early Learning, and social-communication assessments using the Autism Observation Scale for Infants. At 18 to 36 months, a diagnostic evaluation for ASD was performed using the Autism Diagnostic Observation Schedule. RESULTS: Infants with TSC demonstrated delays confined to nonverbal abilities, particularly in the visual domain, which then generalized to more global delays by age 9 months. Twenty-two of 40 infants with TSC were diagnosed with ASD. Both 12-month cognitive ability and developmental trajectories over the second and third years of life differentiated the groups. By 12 months of age, the ASD group demonstrated significantly greater cognitive delays and a significant decline in nonverbal IQ from 12 to 36 months. CONCLUSIONS: This prospective study characterizes early developmental markers of ASD in infants with TSC. The early delay in visual reception and fine motor ability in the TSC group as a whole, coupled with the decline in nonverbal ability in infants diagnosed with ASD, suggests a domain-specific pathway to ASD that can inform more targeted interventions for these high-risk infants.

[Therapeutic possibilities in refractory epilepsy in tuberous sclerosis complex]. / Posibilidades terapeuticas en la epilepsia refractaria en el complejo esclerosis tuberosa.

INTRODUCTION: Tuberous sclerosis complex (TSC) is frequently accompanied by difficult-to-treat epilepsy, which conditions these patients' quality of life and cognitive level. AIM. To describe the epidemiological and clinical characteristics, as well as the treatment of patients affected by TSC with epilepsy. PATIENTS AND METHODS: A retrospective review was carried out of the medical records of 30 patients aged under 18 registered in our database, who had been diagnosed with TSC and epilepsy. RESULTS: The age at onset of epilepsy in the patients with TSC in our series ranged from one month to four years. All of them began with partial crises. Two presented West's syndrome and four others had infantile spasms without hypsarrhythmia. In 19 of the patients, the epilepsy was medication resistant. As regards treatment with antiepileptic drugs, 11 are in monotherapy, 10 in bitherapy, seven in tritherapy and one with four drugs. Two were given ACTH, two carry an implanted vagal nerve stimulator, four receive treatment with everolimus and eight have undergone surgery. CONCLUSIONS: Epilepsy is a very common problem and begins in the early years of life in TSC. There are currently a large number of therapeutic options available, although 63.3% of patients have non-controlled epilepsy and most of them present crises on a daily basis. Poor control of their crises is correlated with mental retardation and autism spectrum disorder. The positive response obtained with other therapeutic possibilities, such as mTOR pathway inhibitors, surgery and vagal nerve stimulator, should be noted.

TITLE: Posibilidades terapeuticas en la epilepsia refractaria en el complejo esclerosis tuberosa.Introduccion. El complejo esclerosis tuberosa (CET) cursa frecuentemente con epilepsia de dificil control, lo que condiciona la calidad de vida y el nivel cognitivo de estos pacientes. Objetivo. Describir las caracteristicas epidemiologicas, clinicas y el tratamiento de los pacientes afectos de CET con epilepsia. Pacientes y metodos. Se han revisado retrospectivamente las historias clinicas de 30 pacientes menores de 18 años, diagnosticados de CET y epilepsia registrados en nuestra base de datos. Resultados. La edad de inicio de la epilepsia en los pacientes con CET en nuestra serie esta comprendida entre el primer mes de vida y los 4 años. Todos comenzaron con crisis parciales. Dos presentaron sindrome de West y cuatro, espasmos infantiles sin hipsarritmia. En 19 de los pacientes, la epilepsia se comporto como farmacorresistente. Respecto al tratamiento con farmacos antiepilepticos, 11 estan en monoterapia, 10 en biterapia, siete en triterapia y uno con cuatro farmacos. Dos recibieron ACTH, dos tienen implantado un estimulador del nervio vago, cuatro reciben tratamiento con everolimus y ocho han sido sometidos a cirugia. Conclusiones. La epilepsia es un problema muy frecuente y de inicio en los primeros años de vida en el CET. Las opciones terapeuticas actuales son muchas, sin embargo el 63,3% de los pacientes tiene una epilepsia no controlada y la mayoria de ellos presenta crisis diarias. El mal control de las crisis se correlaciona con retraso mental y trastorno del espectro autista. Señalar la respuesta positiva obtenida con otras posibilidades terapeuticas: inhibidores de la via mTOR, cirugia y el estimulador del nervio vago.

Screening children with neurofibromatosis type 1 for autism spectrum disorder.

Autism spectrum disorder (ASD) is reported to be increased in neurofibromatosis type 1 (NF1), but it's unknown if ASD screening tools are sensitive and specific for NF1. This study compared the rate at which children with NF1 screen-positive for two ASD screening tools [Modified Checklist for Autism in Toddlers (M-CHAT) and Childhood Autism Spectrum Test (CAST)] to the screen-positive rate of the general population. A retrospective cross-sectional observational design to investigate the association between children with NF1 and at risk status for ASD was used. Medical records of children between 16 months and 11 years of age seen in an NF Clinic were reviewed for an ASD screening questionnaire. There were no statistically significant differences in the screen-positive rate for ASD in NF1 compared to published controls, but mean CAST scores were higher in NF1.

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 ß-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.

Maternal lifestyle and environmental risk factors for autism spectrum disorders.

BACKGROUND: Over the past 10 years, research into environmental risk factors for autism has grown dramatically, bringing evidence that an array of non-genetic factors acting during the prenatal period may influence neurodevelopment. METHODS: This paper reviews the evidence on modifiable preconception and/or prenatal factors that have been associated, in some studies, with autism spectrum disorder (ASD), including nutrition, substance use and exposure to environmental agents. This review is restricted to human studies with at least 50 cases of ASD, having a valid comparison group, conducted within the past decade and focusing on maternal lifestyle or environmental chemicals. RESULTS: Higher maternal intake of certain nutrients and supplements has been associated with reduction in ASD risk, with the strongest evidence for periconceptional folic acid supplements. Although many investigations have suggested no impact of maternal smoking and alcohol use on ASD, more rigorous exposure assessment is needed. A number of studies have demonstrated significant increases in ASD risk with estimated exposure to air pollution during the prenatal period, particularly for heavy metals and particulate matter. Little research has assessed other persistent and non-persistent organic pollutants in association with ASD specifically. CONCLUSIONS: More work is needed to examine fats, vitamins and other maternal nutrients, as well as endocrine-disrupting chemicals and pesticides, in association with ASD, given sound biological plausibility and evidence regarding other neurodevelopmental deficits. The field can be advanced by large-scale epidemiological studies, attention to critical aetiological windows and how these vary by exposure, and use of biomarkers and other means to understand underlying mechanisms.

Socioeconomic status and the risk of suspected autism spectrum disorders among 18-month-old toddlers in Japan: a population-based study.

The association between family socioeconomic status (SES) and the suspected autism spectrum disorder (ASD) status of 18-month-old toddlers was investigated using a population-based sample in Japan, which has a universal healthcare system and a mandatory health checkup system for toddlers. Questionnaires including SES measurements and modified checklist for autism in toddlers were mailed to all families with 18-month-old toddlers in Chiba, a city near Tokyo (N = 6,061; response rate: 64%). The results of logistic regression analysis (which were adjusted for potential confounders) indicated that low maternal education, but not paternal education or family income, were associated with having suspected ASD offspring. Lower maternal education was associated with an increased risk of autistic traits in Japan.

Maternal hormonal interventions as a risk factor for Autism Spectrum Disorder: an epidemiological assessment from India.

Globalization and women empowerment have led to stressful life among Indian women. This stress impairs women's hormonal makeup and menstrual cycle, leading to infertility. National Family Health Survey-3 (NFHS-3) reports a decline in fertility status in India, indicating a rise in various infertility treatments involving hormonal interventions. No studies are available from India on the risk association link between maternal hormonal treatments and ASD. Hence, this study explores the association of maternal hormonal interventions with risk for ASD. Parents of 942 children (471 ASD and 471 controls) across 9 cities in India participated in the questionnaire-based study. The questionnaire was pilot tested and validated for its content and reliability as a psychometric instrument. Data collection was done at 70 centres through direct interaction with parents and with the help of trained staff. Statistical analysis of data was carried out using SAS 9.1.3. Out of the 471 ASD cases analysed, 58 mothers had undergone hormonal interventions (12.3 percent) while there were only 22 mothers among controls who underwent hormonal interventions (4.6 percent). According to logistic regression analysis maternal hormonal intervention (OR=2.24) was a significant risk factor for ASD.

Neurofibromatosis type 1 and autism spectrum disorder.

OBJECTIVE: To determine the prevalence of autism spectrum disorder (ASD) in Neurofibromatosis Type 1 (NF1). METHODS: Second-phase population-based epidemiologic study using an allcase NF1 registry in a defined UK 4.1 million population area. A total of 109 (52.7%) of 207 responders from the initial screening phase were grouped by using the parent-rated Social Responsiveness Scale (SRS) as significant ASD (SRS≥76; n = 32), moderate ASD (SRS ≥ 60<76; n = 29), or non-ASD (SRS <60, n = 48). Twenty-three cases from the significant ASD group, 16 from moderate ASD, and 8 from non-ASD (total n = 47), invited proportionately by random selection, were seen for detailed confirmatory ascertainment. Assessments on Autism Diagnostic Interview-Revised, Autism Diagnostic Observation Scale-Generic, and verbal IQ were combined by using standard Collaborative Program for Excellence in Autism criteria into an ASD categorization for each case (ASD, broad ASD with partial features, non-ASD). A preplanned weighted analysis was used to derive prevalence estimates for the whole population. RESULTS: Fourteen (29.5%) of 47 showed ASD, 13 (27.7%) broad ASD, and 20 (42.5%) non-ASD. The ASD/broad ASD group showed male predominance (1.7:1.0), but did not differ significantly from the non-ASD group on IQ, age, socioeconomic status, inheritance, physical severity, or education. The population prevalence estimate is 24.9% ASD (95% confidence interval 13.1%-42.1%) and 20.8% broad ASD (95% confidence interval 10.0%-38.1%); a total of 45.7% showing some ASD spectrum phenotype. CONCLUSIONS: Findings indicate high prevalence of ASD in NF1, with implications for clinical practice and further research into NF1 as a single-gene model for autism.

Thimerosal exposure and the role of sulfation chemistry and thiol availability in autism.

Autism spectrum disorder (ASD) is a neurological disorder in which a significant number of the children experience a developmental regression characterized by a loss of previously acquired skills and abilities. Typically reported are losses of verbal, nonverbal, and social abilities. Several recent studies suggest that children diagnosed with an ASD have abnormal sulfation chemistry, limited thiol availability, and decreased glutathione (GSH) reserve capacity, resulting in a compromised oxidation/reduction (redox) and detoxification capacity. Research indicates that the availability of thiols, particularly GSH, can influence the effects of thimerosal (TM) and other mercury (Hg) compounds. TM is an organomercurial compound (49.55% Hg by weight) that has been, and continues to be, used as a preservative in many childhood vaccines, particularly in developing countries. Thiol-modulating mechanisms affecting the cytotoxicity of TM have been identified. Importantly, the emergence of ASD symptoms post-6 months of age temporally follows the administration of many childhood vaccines. The purpose of the present critical review is provide mechanistic insight regarding how limited thiol availability, abnormal sulfation chemistry, and decreased GSH reserve capacity in children with an ASD could make them more susceptible to the toxic effects of TM routinely administered as part of mandated childhood immunization schedules.

Analysis of self-selection bias in a population-based cohort study of autism spectrum disorders.

BACKGROUND: This study examined potential self-selection bias in a large pregnancy cohort by comparing exposure-outcome associations from the cohort to similar associations obtained from nationwide registry data. The outcome under study was specialist-confirmed diagnosis of autism spectrum disorders (ASDs). METHODS: The cohort sample (n = 89 836) was derived from the population-based prospective Norwegian Mother and Child Cohort Study and its substudy of ASDs, the Autism Birth Cohort (ABC) study. The nationwide registry data were derived from the Medical Birth Registry of Norway (n = 507 856). The children were born in 1999­2007, and seven prenatal and perinatal exposures were selected for analyses. RESULTS: ASDs were reported for 234 (0.26%) children in the cohort and 2072 (0.41%) in the nationwide population. Compared with the nationwide population, the cohort had an under-representation of the youngest women (<25 years), those who had single status, mothers who smoked during pregnancy, and non-users of prenatal folic acid supplements. The ratios of the adjusted odds ratios (ORs) in the cohort over the adjusted ORs in the nationwide population were as follows; primipara pregnancy: 1.39/1.22, prenatal folic acid use: 0.85/0.86, prenatal smoking: 1.20/1.17, preterm birth (<37 weeks): 1.48/1.42, low birthweight (<2500 g): 1.60/1.58, male sex: 4.39/4.59 (unadjusted only); and caesarean section history: 1.03/1.04. CONCLUSIONS: Associations estimated between ASDs and perinatal and prenatal exposures in the cohort are close to those estimated in the nationwide population. Self-selection does not appear to compromise validity of exposure-outcome associations in the ABC study.

Is a subtype of autism an allergy of the brain?

BACKGROUND: Autism spectrum disorders (ASDs) are characterized by deficits in social communication and language and the presence of repetitive behaviors that affect as many as 1 in 50 US children. Perinatal stress and environmental factors appear to play a significant role in increasing the risk for ASDs. There is no definitive pathogenesis, which therefore significantly hinders the development of a cure. OBJECTIVE: We aimed to identify publications using basic or clinical data that suggest a possible association between atopic symptoms and ASDs, as well as evidence of how such an association could lead to brain disease, that may explain the pathogenesis of ASD. METHODS: PubMed was searched for articles published since 1995 that reported any association between autism and/or ASDs and any one of the following terms: allergy, atopy, brain, corticotropin-releasing hormone, cytokines, eczema, food allergy, food intolerance, gene mutation, inflammation, mast cells, mitochondria, neurotensin, phenotype, stress, subtype, or treatment. RESULTS: Children with ASD respond disproportionally to stress and also present with food and skin allergies that involve mast cells. Brain mast cells are found primarily in the hypothalamus, which participates in the regulation of behavior and language. Corticotropin-releasing hormone is secreted from the hypothalamus under stress and, together with neurotensin, stimulates brain mast cells that could result in focal brain allergy and neurotoxicity. Neurotensin is significantly increased in serum of children with ASD and stimulates mast cell secretion of mitochondrial adenosine triphosphate and DNA, which is increased in these children; these mitochondrial components are misconstrued as innate pathogens, triggering an autoallergic response in the brain. Gene mutations associated with higher risk of ASD have been linked to reduction of the phosphatase and tensin homolog, which inhibits the mammalian target of rapamycin (mTOR). These same mutations also lead to mast cell activation and proliferation. Corticotropin-releasing hormone, neurotensin, and environmental toxins could further trigger the already activated mTOR, leading to superstimulation of brain mast cells in those areas responsible for ASD symptoms. Preliminary evidence indicates that the flavonoid luteolin is a stronger inhibitor of mTOR than rapamycin and is a potent mast cell blocker. CONCLUSION: Activation of brain mast cells by allergic, environmental, immune, neurohormonal, stress, and toxic triggers, especially in those areas associated with behavior and language, lead to focal brain allergies and subsequent focal encephalitis. This possibility is more likely in the subgroup of patients with ASD susceptibility genes that also involve mast cell activation.

Smoking during pregnancy and risk of autism spectrum disorder in a Finnish National Birth Cohort.

BACKGROUND: Results of previous population-based studies examining associations between smoking during pregnancy and autism spectrum disorders (ASD) are contradictory. Furthermore, there is a lack of population-based studies examining the relationship between smoking during pregnancy and the main diagnostic subtypes of ASD. METHODS: We conducted a population-based nested case-control study based on the Finnish Prenatal Study of Autism (FIPS-A) among liveborn infants delivered in Finland between 1987 and 2005. Data on maternal smoking during pregnancy were available from the Finnish Medical Birth Register (FMBR) since October 1990. Data on ASD in the offspring were obtained from the Finnish Hospital Discharge Register (FHDR). RESULTS: Among the three subtypes of ASD, maternal smoking during the whole pregnancy was associated with an increased risk of pervasive developmental disorder (PDD) (odds ratio 1.2, 95% confidence interval 1.0, 1.5). The increase in odds persisted after controlling for maternal age, mother's socio-economic and psychiatric status, and infant's weight for gestational age. However, smoking exposure limited to the first trimester was not associated with PDD or any of the other ASD subtypes. CONCLUSIONS: Maternal smoking is related to a modest increase in risk of PDD, while no associations were observed for childhood autism and Asperger's syndrome.

Role of perfumes in pathogenesis of autism.

Autism spectrum disorders (ASDs) are developmental conditions characterized by deficits in social interaction, verbal and nonverbal communication, and obsessive/stereotyped patterns of behavior. Although there is no reliable neurophysiological marker associated with ASDs, dysfunction of the parieto-frontal mirror neuron system and underdeveloped olfactory bulb (OB) has been associated with the disorder. It has been reported that the number of children who have ASD has increased considerably since the early 1990 s. In developed countries, it is now reported that 1-1.5% of children have ASD, and in the US it is estimated that one in 88 children suffer from ASD. Currently, there is no known cause for ASD. During the last three decades, the most commonly accepted paradigm about autism is that it is a genetically inherited disease. The recent trio analyses, in which both biological parents and the autistic child's exomes are sequenced, do not support this paradigm. On the other hand, the environmental factors that may induce genetic mutations in vitro have not been clearly identified, and there is little irrefutable evidence that pesticides, water born chemicals, or food preservatives play critical roles in inducing the genetic mutations associated with known intellectual deficiencies that have been linked to autism spectrum disorder (ASD). Here, we hypothesize and provide scientific evidence that ASD is the result of exposure to perfumes and cosmetics. The highly mutagenic, neurotoxic, and neuromodulatory chemicals found in perfumes are often overlooked and ignored as a result of a giant loophole in the Federal Fair Packaging and Labeling Act of 1973, which explicitly exempts fragrance producers from having to disclose perfume ingredients on product labels. We hypothesize that perfumes and cosmetics may be important factors in the pathogenesis of ASD. Synthetic perfumes have gained global utility not only as perfumes but also as essential chemicals in detergents, cosmetics, soap, and a wide variety of commonly used items, even in food flavoring to enhance product taste. Here we provide evidence that a majority of perfumes are highly mutagenic at femtomolar concentrations, and cause significant neuromodulations in human neuroblastoma cells at extremely low levels of concentration, levels that are expected to reach a developing fetal brain if the pregnant mothers are exposed to these chemicals.

Can bronchoscopic airway anatomy be an indicator of autism?

Bronchoscopic evaluations revealed that some children have double branching of bronchi (designated "doublets") in the lower lungs airways, rather than normal, single branching. Retrospective analyses revealed only one commonality in them: all subjects with doublets also had autism or autism spectrum disorder (ASD). That is, 49 subjects exhibited the presence of initial normal anatomy in upper airway followed by doublets in the lower airway. In contrast, the normal branching pattern was noted in all the remaining 410 subjects who did not have a diagnosis of autism/ASD. We propose that the presence of doublets might be an objective, reliable, and valid biologic marker of autism/ASD.

Narrowly versus broadly defined autism spectrum disorders: differences in pre- and perinatal risk factors.

This study examined the differential contribution of pre- and perinatal risks in narrowly versus broadly defined autism spectrum disorder (ASD) and across core symptom domains, IQ and co-morbid problems. Children with a DSM-IV diagnosis of autistic disorder (AD) (n = 121) or pervasive developmental disorder not otherwise specified (PDD-NOS) (n = 75) were compared to a typical control sample (n = 311). Diagnoses were based on extensive assessments between 12 and 49 months of age (M = 33.3, SD = 6.4) and re-evaluated at 43-98 months (M = 68.1, SD = 10.7) in 70% of the cases. Compared with controls, cases with ASD were more likely to be firstborn and show a suboptimal condition after birth. Case mothers reported more infections and more stress during pregnancy. Although the ASD subgroups showed mostly overlapping risks, cases with PDD-NOS differed from those with AD by higher exposure to smoking during pregnancy (SDP) and by a negative association of smoking with IQ, regardless of confounders. SDP appears to contribute more to broadly defined (PDD-NOS) than to narrowly defined ASD (AD). Findings suggest differences in etiological contributors between ASD phenotypes.