Autism families with a high incidence of alcoholism

Risk of parental major psychiatric disorders in patients with comorbid autism spectrum disorder and attention deficit hyperactivity disorder: A population-based family-link study

OBJECTIVE

Few studies have investigated the parental risk of major psychiatric disorders among patients with comorbid autism spectrum disorder and attention deficit hyperactivity disorder. This study examined the differences in such risk among patients with autism spectrum disorder-only, with attention deficit hyperactivity disorder-only and both conditions.

METHODS

Between 2001 and 2011, we enrolled 132,624 patients with autism spectrum disorder or attention deficit hyperactivity disorder and 1:10 matched controls for age, sex and demographics from the National Health Insurance Database of Taiwan. Poisson regression models were used to examine the risk of five major psychiatric disorders in the patients' parents compared with those of the controls, including schizophrenia, bipolar disorder, major depressive disorder, alcohol use disorder, and substance use disorder. Patients were classified into the autism spectrum disorder-only, attention deficit hyperactivity disorder-only and dual-diagnosis groups.

RESULTS

The parents of attention deficit hyperactivity disorder-only and dual-diagnosis groups had a higher likelihood to be diagnosed with (odds ratios [95% confidence intervals]) schizophrenia (attention deficit hyperactivity disorder: 1.48 [1.39, 1.57]; dual: 1.79 [1.45, 1.20]), bipolar disorder (attention deficit hyperactivity disorder: 1.91 [1.82, 2.01]; dual: 1.81 [1.51, 2.17]), major depressive disorder (attention deficit hyperactivity disorder: 1.94 [1.89, 2.00]; dual: 1.99 [1.81, 2.20]), alcohol use disorder (attention deficit hyperactivity disorder: 1.39 [1.33, 1.45]; dual: 1.20 [1.01, 1.42]) and substance use disorder (attention deficit hyperactivity disorder: 1.66 [1.59, 1.73]; dual: 1.34 [1.13, 1.58]) than the controls. In contrast, the parents of autism spectrum disorder-only group had a higher likelihood to be diagnosed with schizophrenia (1.77 [1.46, 2.15]) and major depressive disorder (1.45 [1.32, 1.61]) and a lower likelihood to be diagnosed with alcohol use disorder (0.68 [0.55, 0.84]) than the controls.

CONCLUSION

The autism spectrum disorder-only group had a different parental incidence of major psychiatric disorders than the attention deficit hyperactivity disorder-only and dual-diagnosis groups. Our findings have implications for clinical practice and future genetic research.

Autism Spectrum Disorder and Fetal Alcohol Spectrum Disorder: A Literature Review

Fetal alcohol spectrum disorders (FASD) are a group of conditions associated with the effects of prenatal alcohol exposure and characterized by somatic and neuropsychological alterations. On the other hand, autism spectrum disorder (ASD) is characterized by a multifaceted neurobehavioral syndrome. Since alcohol can affect every stage of brain development, some authors hypothesized that in utero alcohol exposure might be linked to an increased risk of ASD in subjects with genetic vulnerability. The present review aimed to summarize the available literature on the possible association between FASD and ASD, also focusing on the reported clinical overlaps and on the possible shared pathogenic mechanisms. Studies in this field have stressed similarities and differences between the two conditions, leading to controversial results. The available literature also highlighted that both the disorders are often misdiagnosed or underdiagnosed, stressing the need to broaden the perspective, paying specific attention to milder presentations and sub-syndromic traits.

Maternal Alcohol Consumption During Pregnancy and the Risk of Autism Spectrum Disorders in Offspring: A Retrospective Analysis of the Millennium Cohort Study

The objective of this retrospective analysis of the longitudinal Millennium Cohort Study was to examine whether maternal alcohol consumption in pregnancy (MACP) is associated with the development of childhood autism spectrum disorders (ASD). Data on MACP and ASD were obtained from parental questionnaires. There were 18,168 singleton mother–child pairs with data on MACP, and 12,595 answered the question on ASD when the children were 11 years old. No statistically significant association was found between MACP and ASD for light (OR 0.78, 95% CI 0.48–1.29), moderate (OR 0.89, 95% CI 0.35–2.27), or heavy (OR 1.54, 95% CI 0.56–4.21) MACP. Alcohol consumption during pregnancy was not associated with the risk of developing ASD in this study cohort.

Increased Risk for Substance Use-Related Problems in Autism Spectrum Disorders: A Population-Based Cohort Study

Despite limited and ambiguous empirical data, substance use-related problems have been assumed to be rare among patients with autism spectrum disorders (ASD). Using Swedish population-based registers we identified 26,986 individuals diagnosed with ASD during 1973–2009, and their 96,557 non-ASD relatives. ASD, without diagnosed comorbidity of attention deficit hyperactivity disorder (ADHD) or intellectual disability, was related to a doubled risk of substance use-related problems. The risk of substance use-related problems was the highest among individuals with ASD and ADHD. Further, risks of substance use-related problems were increased among full siblings of ASD probands, half-siblings and parents. We conclude that ASD is a risk factor for substance use-related problems. The elevated risks among relatives of probands with ASD suggest shared familial (genetic and/or shared environmental) liability.

Chromosomal microarray analysis in a cohort of underrepresented population identifies SERINC2 as a novel candidate gene for autism spectrum disorder

Chromosomal microarray (CMA) is now recognized as the first-tier genetic test for detection of copy number variations (CNVs) in patients with autism spectrum disorder (ASD). The aims of this study were to identify known and novel ASD associated-CNVs and to evaluate the diagnostic yield of CMA in Thai patients with ASD. The Infinium CytoSNP-850K BeadChip was used to detect CNVs in 114 Thai patients comprised of 68 retrospective ASD patients (group 1) with the use of CMA as a second line test and 46 prospective ASD and developmental delay patients (group 2) with the use of CMA as the first-tier test. We identified 7 (6.1%) pathogenic CNVs and 22 (19.3%) variants of uncertain clinical significance (VOUS). A total of 29 patients with pathogenic CNVs and VOUS were found in 22% (15/68) and 30.4% (14/46) of the patients in groups 1 and 2, respectively. The difference in detected CNV frequencies between the 2 groups was not statistically significant (Chi square = 1.02, df = 1, P = 0.31). In addition, we propose one novel ASD candidate gene, SERINC2, which warrants further investigation. Our findings provide supportive evidence that CMA studies using population-specific reference databases in underrepresented populations are useful for identification of novel candidate genes.

Autism Spectrum Disorder in Children Adopted After Early Care Breakdown

Syndromic autism has been described in children adopted after orphanage rearing. We investigated whether the same existed in children adopted after family breakdown. Families of 54/60 adopted children aged 6–11 years (mean 102 months; SD 20; 45 % male) returned screening questionnaires for autism spectrum disorder (ASD); 21/54 (39 %) screened positive. Detailed in-person phenotyping of screen positive cases showed ASD in 6/54 (11 %), Broad ASD (sub threshold traits) in 10/54 (18.5 %); 5/54 (9 %) screened false positive. The ASD group showed impairments across both social communication and restrictive repetitive behaviour domains, Broad ASD was more mixed. These rates, much higher than population prevalence, are comparable with institutionalised samples. There are implications for developmental science, and assessment, treatment and policy for adopted children.

The Pivotal Role of Aldehyde Toxicity in Autism Spectrum Disorder: The Therapeutic Potential of Micronutrient Supplementation

Autism spectrum disorder (ASD) is characterized by social and communication impairments as well as by restricted, repetitive patterns of behavior and interests. Genomic studies have not revealed dominant genetic errors common to all forms of ASD. So ASD is assumed to be a complex disorder due to mutations in hundreds of common variants. Other theories argue that spontaneous DNA mutations and/or environmental factors contribute to as much as 50% of ASD. In reviewing potential genetic linkages between autism and alcoholism, it became apparent that all theories of ASD are consistent with aldehyde toxicity, in which endogenous and exogenous aldehydes accumulate as a consequence of mutations in key enzymes. Aldehyde toxicity is characterized by cell-localized, micronutrient deficiencies in sulfur-containing antioxidants, thiamine (B1), pyridoxine (B6), folate, Zn²⁺, possibly Mg²⁺, and retinoic acid, causing oxidative stress and a cascade of metabolic disturbances. Aldehydes also react with selective cytosolic and membrane proteins in the cell of origin; then some types migrate to damage neighboring cells. Reactive aldehydes also form adducts with DNA, selectively mutating bases and inducing strand breakage. This article reviews the relevant genomic, biochemical, and nutritional literature, which supports the central hypothesis that most ASD symptoms are consistent with symptoms of aldehyde toxicity. The hypothesis represents a paradigm shift in thinking and has profound implications for clinical detection, treatment, and even prevention of ASD. Insight is offered as to which neurologically afflicted children might successfully be treated with micronutrients and which children are unlikely to be helped. The aldehyde toxicity hypothesis likely applies to other neurological disorders.

Onset of maternal psychiatric disorders after the birth of a child with autism spectrum disorder: A retrospective cohort study

BACKGROUND

Mothers of a child with autism spectrum disorder have more psychiatric disorders after the birth of their child. This might be because they have more psychiatric disorders before the birth, or the increase could be related to the burden of caring for their child.

AIMS

We aimed to calculate the incidence of a psychiatric diagnosis in women with no psychiatric history after the birth of their eldest child with autism spectrum disorder compared to women with no child with autism spectrum disorder or intellectual disability and no psychiatric history.

METHODS

By linking datasets from Western Australian population-based registries, we calculated the incidence of a psychiatric disorder in mothers of children with autism spectrum disorder and compared to mothers of children with no autism spectrum disorder or intellectual disability. Negative binomial regression using STATA 13 was used for all analyses.

RESULTS

Apart from alcohol and substance abuse, mothers of children with autism spectrum disorder had higher incidences of all categories of psychiatric disorders than other mothers.

CONCLUSION AND IMPLICATIONS

The increase of psychiatric disorders in mothers of children with autism spectrum disorder and no psychiatric history compared to similar mothers with no child with autism spectrum disorder or intellectual disability might be due to a pre-existing genetic disposition coupled with an environmental trigger provided by the challenges of raising their children with autism spectrum disorder. In addition, the increased burden borne by the mothers of children with autism spectrum disorder might result in a higher incidence of psychiatric disorders in mothers who are not genetically disposed.

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.

AMPAKINE enhancement of social interaction in the BTBR mouse model of autism

Autism is a neurodevelopmental disorder in which the first diagnostic symptom is unusual reciprocal social interactions. Approximately half of the children diagnosed with an autism spectrum disorder also have intellectual impairments. General cognitive abilities may be fundamental to many aspects of social cognition. Cognitive enhancers could conceivably be of significant benefit to children and adults with autism. AMPAKINE compounds are a novel class of pharmacological agents that act as positive modulators of AMPA receptors to enhance excitatory glutamatergic neurotransmission. This class of compounds was reported to improve learning and memory in several rodent and non-human primate tasks, and to normalize respiratory abnormalities in a mouse model of Rett syndrome. Here we evaluate the actions of AMPA compounds in adult male and female BTBR mice, a well characterized mouse model of autism. Acute treatment with CX1837 and CX1739 reversed the deficit in sociability in BTBR mice on the most sensitive parameter, time spent sniffing a novel mouse as compared to time spent sniffing a novel object. The less sensitive parameter, time in the chamber containing the novel mouse versus time in the chamber containing the novel object, was not rescued by CX1837 or CX1739 treatment. Preliminary data with CX546, in which β-cyclodextrin was the vehicle, revealed behavioral effects of the acute intraperitoneal and oral administration of vehicle alone. To circumvent the artifacts introduced by the vehicle administration, we employed a novel treatment regimen using pellets of peanut butter for drug delivery. Absence of vehicle treatment effects when CX1837 and CX1739 were given in the peanut butter pellets, to multiple cohorts of BTBR and B6 control mice, confirmed that the pharmacologically-induced improvements in sociability in BTBR were not confounded by the administration procedures. The highest dose of CX1837 improved the cognitive deficit in novel object recognition in BTBR. No drug effects were detected on the high levels of repetitive self-grooming in BTBR. In open field tests, CX1837 and CX1739 did not induce hyperactivity or sedation in either strain. It is interesting to speculate that the ability of CX1837 and CX1739 to restore aspects of sociability in BTBR mice could utilize synaptic mechanisms regulating social cognition, suggesting a potential pharmacological target for interventions to treat symptoms of autism. This article is part of a Special Issue entitled 'Cognitive Enhancers'.

Parent and family impact of autism spectrum disorders: a review and proposed model for intervention evaluation

Raising a child with an autism spectrum disorder (ASD) can be an overwhelming experience for parents and families. The pervasive and severe deficits often present in children with ASD are associated with a plethora of difficulties in caregivers, including decreased parenting efficacy, increased parenting stress, and an increase in mental and physical health problems compared with parents of both typically developing children and children with other developmental disorders. In addition to significant financial strain and time pressures, high rates of divorce and lower overall family well-being highlight the burden that having a child with an ASD can place on families. These parent and family effects reciprocally and negatively impact the diagnosed child and can even serve to diminish the positive effects of intervention. However, most interventions for ASD are evaluated only in terms of child outcomes, ignoring parent and family factors that may have an influence on both the immediate and long-term effects of therapy. It cannot be assumed that even significant improvements in the diagnosed child will ameliorate the parent and family distress already present, especially as the time and expense of intervention can add further family disruption. Thus, a new model of intervention evaluation is proposed, which incorporates these factors and better captures the transactional nature of these relationships.

Autism spectrum disorders--a genetics review

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

The epidemiology of autism spectrum disorders

Autism spectrum disorders (ASDs) are complex, lifelong, neurodevelopmental conditions of largely unknown cause. They are much more common than previously believed, second in frequency only to mental retardation among the serious developmental disorders. Although a heritable component has been demonstrated in ASD etiology, putative risk genes have yet to be identified. Environmental risk factors may also play a role, perhaps via complex gene-environment interactions, but no specific exposures with significant population effects are known. A number of endogenous biomarkers associated with autism risk have been investigated, and these may help identify significant biologic pathways that, in turn, will aid in the discovery of specific genes and exposures. Future epidemiologic research should focus on expanding population-based descriptive data on ASDs, exploring candidate risk factors in large well-designed studies incorporating both genetic and environmental exposure data and addressing possible etiologic heterogeneity in studies that can stratify case groups and consider alternate endophenotypes.

Psychiatric disorders in the parents of individuals with infantile autism: a case-control study

BACKGROUND

The rates and types of psychiatric disorders were studied in the parents of individuals with infantile autism (IA).

SAMPLING AND METHODS

To estimate the prevalence and types of psychiatric disorders, the parents of 115 individuals with IA and the parents of 330 controls from the general population were screened through the nationwide Danish Psychiatric Central Register covering a period of 33 years. The IA individuals had been seen as in-patients at two university clinics of child psychiatry during a 25-year period and had been referred from the entire country of Denmark.

RESULTS

Psychiatric disorders were found in 15.7% of mothers with autistic children, which was significantly higher than the 8.2% found in the control group. The only diagnostic category in which a statistically significant overrepresentation could be found was that of personality disorder. A personality disorder diagnosis was found in 7.8% of mothers with autistic children in comparison to 2.1% of mothers in the control group.

CONCLUSION

The findings so far suggest that in future studies it is important to pay attention to issues such as relatives examined, control groups and methods of data collection.

Joubert syndrome is not a cause of classical autism

A previous report noted a 27% prevalence of autism in Joubert syndrome (JS), raising the question of overlapping etiologies. Family studies have shown that autism is characterized by family loading for a number of specific behavioral and psychiatric disorders and that the sib recurrence risk is around 4%. The purpose of this study is to determine whether children with Joubert and their families show behavioral or genetic characteristics similar to autism. Thirty-one volunteer Joubert families were identified. Parents completed a semi-structured family history interview and the Autism Behavioral Checklist. Rates of family loading for neuropsychiatric disorders in the JS families were compared to autism family history data and Down syndrome (DS) controls. The JS families had significantly lower rates of autism, alcoholism, cognitive, and language disorders than the autism families. Their rate of depression was lower, but not significantly different from that found in autism families. None of the JS children met the clinical cut-off for autism based on parental symptom report and the sib recurrence risk was 32% for the JS families compared to 4% for the autism and 0% for DS families. These data indicate that JS is a genetically distinct disorder from autism. Different genes with different inheritance patterns that affect neurodevelopment of the cerebellum could explain the clinical similarities previously reported in JS and autism.