Clinical and Laboratory Data in a Sample of Greek Children with Autism Spectrum Disorders

Factor associated with the occurrence of epilepsy in autism: a systematic review

This systematic review aimed to identify factors significantly associated with the occurrence of epilepsy in autistic individuals and to consider the impact of study quality on findings. Electronic databases were systematically searched on October 2nd, 2020 and records retrieved were limited to those published from 2000 onwards. Study quality was categorised as 'good', 'moderate' or 'weak'. Fifty-three studies were included and in studies where the prevalence of epilepsy was reported (n = 257,892), 18,254 (7%) had co-occurring epilepsy. Intellectual disability/cognitive impairment was the most commonly reported risk factor associated with occurrence of epilepsy in autistic individuals. The evidence supporting other, potentially relevant factors was weak and inconsistent and requires further evaluation. Only 9/53 studies were considered 'good' quality.

Predictors of an earlier diagnosis of Autism Spectrum Disorder in children and adolescents: a systematic review (1987-2017)

Autism Spectrum Disorder (ASD) is an early onset neurodevelopmental disorder in which the first signs generally emerge at approximately 12 months of age but its diagnosis is feasible only from the age of 18 months. According to the literature, the average age of diagnosis ranges from 2.7 to 7.2 years, which raises the question of factors associated with early diagnosis as a condition for early intervention. In this systematic review, we aim to identify clinical, social, and environmental factors associated with the age at which the diagnosis of ASD is confirmed in children. A literature search was performed in the Pubmed, Web of Sciences, PsycInfo, and Cochrane databases. Among the 530 publications identified, 50 were selected according to the inclusion criteria. This review focuses on studies conducted in 21 countries using data collected over a period from 1987 to 2017. These studies were published before December 31st, 2019. The results suggest that the diagnosis of ASD occurs earlier if there is a delay in social communication or the presence of intellectual disability. There is a low level of evidence concerning associations between the age at diagnosis and sex, race, parental education, or socioeconomic status and accessibility to health care. Further studies using large and well-characterized data sets are needed to simultaneously explore clinical and socio-environmental factors involved in early diagnosis.

Decreased in vivo glutamate/GABA ratio correlates with the social behavior deficit in a mouse model of autism spectrum disorder

To diagnose autism spectrum disorder (ASD), researchers have sought biomarkers whose alterations correlate with the susceptibility to ASD. However, biomarkers closely related to the pathophysiology of ASD are lacking. Even though excitation/inhibition (E/I) imbalance has been suggested as an underlying mechanism of ASD, few studies have investigated the actual ratio of glutamate (Glu) to γ-aminobutyric acid (GABA) concentration in vivo. Moreover, there are controversies in the directions of E/I ratio alterations even in extensively studied ASD animal models. Here, using proton magnetic resonance spectroscopy (¹H-MRS) at 9.4T, we found significant differences in the levels of different metabolites or their ratios in the prefrontal cortex and hippocampus of Cntnap2^−/− mice compared to their wild-type littermates. The Glu/GABA ratio, N-acetylaspartate (NAA)/total creatine (tCr) ratio, and tCr level in the prefrontal cortex were significantly different in Cntnap2^−/− mice compared to those in wild-type mice, and they significantly correlated with the sociability of mice. Moreover, receiver operating characteristic (ROC) analyses indicated high specificity and selectivity of these metabolites in discriminating genotypes. These results suggest that the lowered Glu/GABA ratio in the prefrontal cortex along with the changes in the other metabolites might contribute to the social behavior deficit in Cntnap2^−/− mice. Our results also demonstrate the utility of ¹H-MRS in investigating the underlying mechanisms or the diagnosis of ASD.

Autism: Screening of inborn errors of metabolism and unexpected results

In this study, the aim was to examine patients with inborn errors of metabolism (IEM) who presented with only autism, without any other findings, to suggest any other neurological and genetic disorders. To investigate IEM, data of the hospital records of 247 patients who were referred from pediatric psychiatric to pediatric metabolism outpatient clinics due to further evaluation of autism spectrum disorders (ASD) were examined. Among them, 237 patients were evaluated for IEM leading to ASDs. Organic acidemias, phenylketonuria, tetrahydrobiopterin and neutrotransmitter disorders, biotinidase deficiency, Smith-Lemni-Opitz syndrome, disorders of cerebral creatine metabolism, urea cycle defects, homocystinuria, purine-pyrimidine metabolism disorders, mitochondrial disorders, cerebrotendinous xantomatosis, mucopolysaccaridosis, and glucose 6 phosphate dehydrogenase deficiency were screened with complete blood counts, complete biochemical analyses, homocysteine levels, an arterial blood gase, and metabolic investigations. Six patients were diagnosed as follows: one with phenylketonuria (PKU), one with cerebral creatine deficiency, one with hypobetalipoproteinemia, one with glycogen storage disease type IX-a, one with dihydropyrimidine dehydrogenase deficiency, and one with succinic semialdehyde dehydrogenase deficiency (SSADHD). Forty-six patients screened for IEM were from consanguineous families, among them, one was diagnosed with FKU and the other was with SSADHD. It would not be expected to find PKU in a 5-year-old patient as a result of newborn screening, but she could not been screened due to being a refugee. The diagnosed diseases were rare presentations of the diseases and furthermore, the diagnosis of hypobetalipoproteinemia and glycogen storage disease type IX-a were surprising with the only presentation of ASDs. LAY SUMMARY: It is well-known that some types of inborn errors of metabolism (IEM) may present with that of autism spectrum disorders (ASDs). This study suggests that in countries where consanguinity marriages are common such as Turkey and refugees whose escaped from neonatal screening are present, patients with ASD should be screened for IEMs. The results can surprise the physicians with a very rare cause of autism that has never been thought. Autism Res 2021, 14: 887-896. © 2021 International Society for Autism Research, Wiley Periodicals LLC.

Neurological disorders in autism: A systematic review and meta-analysis

LAY ABSTRACT

Neurological disorders, such as epilepsy and cerebral palsy, have been reported to occur among individuals with autism beyond chance and may have an impact on daily living across the lifespan. Although there has been research investigating neurological disorders in autism, the findings are not always conclusive. Previous summaries of existing studies have not evaluated the full range of neurological disorders. This study aimed to comprehensively explore the neurological problems appearing in autism to provide updated information that is needed for better healthcare and support in this population. We looked at already published studies focusing on risk or frequency of neurological disorders in autism. Our results suggest that individuals with autism are more likely than the general population to have a range of neurological disorders, including epilepsy, macrocephaly, hydrocephalus, cerebral palsy, migraine/headache, and inborn abnormalities of the nervous system. In order to provide individualized healthcare and support of high quality to individuals diagnosed with autism, health care professionals and other support providers need to be attentive to neurological complications. To further improve our understanding about the link between autism and neurological disorders, future research should follow the neurological health of children who are diagnosed with or are at increased likelihood of autism.

Relationship between toxoplasmosis and autism: A systematic review and meta-analysis

Toxoplasma gondii (T. gondii) is a foodborne parasite that is investigated in many psychiatric diseases, such as autism spectrum disorders (ASD). Therefore, a systematic literature review was conducted searching seven electronic databases on the prevalence of T. gondii antibodies among autism patients. The current study involved sensitivity analysis, meta-regression, subgroup analysis, publication bias test, and quality assessment of studies. On the basis of the findings, the odds ratio (OR) of latent Toxoplasma infection 1.93 (95% confidence intervals (CI): 1.01-3.66) was associated with ASD risk. However, there was no relationship between acute infection and ASD 0.39 (95% CI: 0.18-0.87). The obtained results of Begg's and Egger's tests showed no publication bias (P = 0.851 and P = 0.297, respectively). The sensitivity analysis confirmed robust and stable estimates with a significant level of heterogeneity (I² = 78.1%, P < 0.000). Of the investigated patients' characteristics, only the gender variable was analyzed, indicating the combined ORs of 2.63 (95% CI: 0.29-23.63) in females and 2.62 (95% CI: 0.94-7.30) in male participants. This study showed that toxoplasmosis plays an important role as a risk factor for autism. However, further prospective investigations are highly recommended to illuminate the developmental pathways to this disorder and provide new strategies for the prevention and treatment of this disease.

Clinical Phenotypes of Carriers of Mutations in CHD8 or Its Conserved Target Genes

BACKGROUND

Variants disruptive to CHD8 (which codes for the protein CHD8 [chromodomain-helicase-DNA-binding protein 8]) are among the most common mutations revealed by exome sequencing in autism spectrum disorder (ASD). Recent work has indicated that CHD8 plays a role in the regulation of other ASD-risk genes. However, it is unclear whether a possible shared genetic ontology extends to the phenotype.

METHODS

This study (N = 143; 42.7% female participants) investigated clinical and behavioral features of individuals ascertained for the presence of a known disruptive ASD-risk mutation that is 1) CHD8 (CHD8 group) (n = 15), 2) a gene targeted by CHD8 (target group) (n = 22), or 3) a gene without confirmed evidence of being targeted by CHD8 (other gene group) (n = 106).

RESULTS

Results indicated shared features between the CHD8 and target groups that included less severe adaptive deficits in communication skills, similar functional language, more social motivation challenges in those with ASD, larger head circumference, higher weight, and lower seizure prevalence relative to the other gene group.

CONCLUSIONS

These similarities suggest broader genetic ontology accounts for aspects of phenotypic heterogeneity. Improved understanding of the relationships between related disruptive gene events may lead us to improved understanding of shared mechanisms and lead to more focused treatments for individuals with known genetic mutations.

Autism spectrum disorders in propionic acidemia patients

Propionic acidemia is the result of a deficiency in propionyl-CoA carboxylase activity. Chronic neurologic and cognitive complications frequently occur, but the psychiatric evolution of the disorder is not well documented. We conducted a pedopsychiatric evaluation of 19 children, adolescents and young adults, aged between 2 and 25 years, using ADI-R, CARS-T, as well as ADOS when autism spectrum disorder was suspected. Previous psychometric examinations were also taken into consideration. Thirteen patients had an IQ < 80. Two patients presented with autism and two additional patients with other autism spectrum disorders. Five patients did not fulfill diagnostic criteria for autism spectrum disorder but showed difficulties indicative of a broader autism phenotype (BAP). Four other patients had severe anxiety manifestations related to their disease. Two patients presented with acute psychotic episodes. The number of decompensations in the first 3 years of life was lower in patients with autism spectrum disorder or related symptoms. These patients were also older when they were assessed (median age of 15 years old versus 11 years old). There was no significant correlation between 3-hydroxypropionate levels during the first 6 years of life and autism spectrum disorder diagnosis. In conclusion, autism spectrum disorder is frequent in patients with propionic acidemia. These patients should undergo in-depth psychiatric evaluation and be screened for autism spectrum disorder. Further studies are needed to understand the underlying mechanisms.

Variability of Creatine Metabolism Genes in Children with Autism Spectrum Disorder

Creatine deficiency syndrome (CDS) comprises three separate enzyme deficiencies with overlapping clinical presentations: arginine:glycine amidinotransferase (GATM gene, glycine amidinotransferase), guanidinoacetate methyltransferase (GAMT gene), and creatine transporter deficiency (SLC6A8 gene, solute carrier family 6 member 8). CDS presents with developmental delays/regression, intellectual disability, speech and language impairment, autistic behaviour, epileptic seizures, treatment-refractory epilepsy, and extrapyramidal movement disorders; symptoms that are also evident in children with autism. The objective of the study was to test the hypothesis that genetic variability in creatine metabolism genes is associated with autism. We sequenced GATM, GAMT and SLC6A8 genes in 166 patients with autism (coding sequence, introns and adjacent untranslated regions). A total of 29, 16 and 25 variants were identified in each gene, respectively. Four variants were novel in GATM, and 5 in SLC6A8 (not present in the 1000 Genomes, Exome Sequencing Project (ESP) or Exome Aggregation Consortium (ExAC) databases). A single variant in each gene was identified as non-synonymous, and computationally predicted to be potentially damaging. Nine variants in GATM were shown to have a lower minor allele frequency (MAF) in the autism population than in the 1000 Genomes database, specifically in the East Asian population (Fisher’s exact test). Two variants also had lower MAFs in the European population. In summary, there were no apparent associations of variants in GAMT and SLC6A8 genes with autism. The data implying there could be a lower association of some specific GATM gene variants with autism is an observation that would need to be corroborated in a larger group of autism patients, and with sub-populations of Asian ethnicities. Overall, our findings suggest that the genetic variability of creatine synthesis/transport is unlikely to play a part in the pathogenesis of autism spectrum disorder (ASD) in children.

Epigenetic Treatment of Neuropsychiatric Disorders: Autism and Schizophrenia

Neuropsychiatric disorders are a heterogeneous group of conditions that often share underlying mitochondrial dysfunction and biological pathways implicated in their pathogenesis, progression, and treatment. To date, these disorders have proven notoriously resistant to molecular-targeted therapies, and clinical options are relegated to interventional types, which do not address the core symptoms of the disease. In this review, we discuss emerging epigenetic-driven approaches using novel acylcarnitine esters (carnitinoids) that act on master regulators of antioxidant and cytoprotective genes and mitophagic pathways. These carnitinoids are actively transported, mitochondria-localizing, biomimetic coenzyme A surrogates of short-chain fatty acids, which inhibit histone deacetylase and may reinvigorate synaptic plasticity and protect against neuronal damage. We outline these neuroprotective effects in the context of treatment of neuropsychiatric disorders such as autism spectrum disorder and schizophrenia.

Prevalence of Creatine Deficiency Syndromes in Children With Nonsyndromic Autism

BACKGROUND AND OBJECTIVE

Creatine deficiency may play a role in the neurobiology of autism and may represent a treatable cause of autism. The goal of the study was to ascertain the prevalence of creatine deficiency syndromes (CDSs) in children with autism spectrum disorder (ASD).

METHODS

In a prospective multicenter study, 443 children were investigated after a confirmed diagnosis of ASD. Random spot urine screening for creatine metabolites (creatine, guanidinoacetate, creatinine, and arginine) with liquid chromatography-tandem mass spectrometry and second-tier testing with high-performance liquid chromatography methodology was followed by recall testing in 24-hour urines and confirmatory testing by Sanger-based DNA sequencing of GAMT, GATM, and SLC6A8 genes. Additional diagnostic tests included plasma creatine metabolites and in vivo brain proton magnetic resonance spectroscopy. The creatine metabolites in spot urine in the autism group were compared with 128 healthy controls controlled for age.

RESULTS

In 443 subjects with ASD investigated for CDS, we had 0 events (event: 0, 95% confidence interval 0-0.0068), therefore with 95% confidence the prevalence of CDS is <7 in 1000 children with ASD. The autism and control groups did not vary in terms of creatine metabolites (P > .0125) in urine.

CONCLUSION

Our study revealed a very low prevalence of CDS in children with nonsyndromic ASD and no obvious association between creatine metabolites and autism. Unlike our study population, we expect more frequent CDS among children with severe developmental delay, speech impairment, seizures, and movement disorders in addition to impairments in social communication, restricted interests, and repetitive behaviors.

Head circumference and brain size in autism spectrum disorder: A systematic review and meta-analysis

Macrocephaly and brain overgrowth have been associated with autism spectrum disorder. We performed a systematic review and meta-analysis to provide an overall estimate of effect size and statistical significance for both head circumference and total brain volume in autism. Our literature search strategy identified 261 and 391 records, respectively; 27 studies defining percentages of macrocephalic patients and 44 structural brain imaging studies providing total brain volumes for patients and controls were included in our meta-analyses. Head circumference was significantly larger in autistic compared to control individuals, with 822/5225 (15.7%) autistic individuals displaying macrocephaly. Structural brain imaging studies measuring brain volume estimated effect size. The effect size is higher in low functioning autistics compared to high functioning and ASD individuals. Brain overgrowth was recorded in 142/1558 (9.1%) autistic patients. Finally, we found a significant interaction between age and total brain volume, resulting in larger head circumference and brain size during early childhood. Our results provide conclusive effect sizes and prevalence rates for macrocephaly and brain overgrowth in autism, confirm the variation of abnormal brain growth with age, and support the inclusion of this endophenotype in multi-biomarker diagnostic panels for clinical use.

Anthropometric assessment of a Middle Eastern group of autistic children

BACKGROUND

Growth abnormalities are uniquely associated with autism spectrum disorders (ASD); however, the extent to which growth abnormalities are present has hardly been investigated. The current study aims to compare the differences in anthropometric parameters in a group of autistic Egyptian children and the healthy normal population.

METHODS

We recruited 100 children with ASD from the Outpatient Clinic for "Autistic Children" at the Medical Research Hospital of Excellence, National Research Centre in Cairo, Egypt. They were diagnosed by DSM-IV criteria of the American Psychiatric Association, Autism Diagnostic Interview-Revised, and Childhood Autism Rating Scale. Of these children at age of 3-10 years, 71 were males and 29 females. Eight anthropometric parameters were assessed in view of data of the healthy Egyptians of pertinent sex and age.

RESULTS

Weight and body mass index increased because of a significant increase in subcutaneous fat thickness. This tendency with a probable decrease in muscle mass was more evident in male or in older children, likely resulting from sedentary life style and food selectivity.

CONCLUSIONS

The Z head circumference score and its variance significantly increased especially in males or older children, suggesting the relative overgrowth of the brain in a substantial percentage of Egyptian children with autism. We concluded that increased fat composition in Egyptian autistic children with decreased muscle mass necessitates tailoring a specially designed food supplementation program to ameliorate the severity of autism symptoms.

Adjusting head circumference for covariates in autism: clinical correlates of a highly heritable continuous trait

BACKGROUND

Brain development follows a different trajectory in children with autism spectrum disorders (ASD) than in typically developing children. A proxy for neurodevelopment could be head circumference (HC), but studies assessing HC and its clinical correlates in ASD have been inconsistent. This study investigates HC and clinical correlates in the Simons Simplex Collection cohort.

METHODS

We used a mixed linear model to estimate effects of covariates and the deviation from the expected HC given parental HC (genetic deviation). After excluding individuals with incomplete data, 7225 individuals in 1891 families remained for analysis. We examined the relationship between HC/genetic deviation of HC and clinical parameters.

RESULTS

Gender, age, height, weight, genetic ancestry, and ASD status were significant predictors of HC (estimate of the ASD effect = .2 cm). HC was approximately normally distributed in probands and unaffected relatives, with only a few outliers. Genetic deviation of HC was also normally distributed, consistent with a random sampling of parental genes. Whereas larger HC than expected was associated with ASD symptom severity and regression, IQ decreased with the absolute value of the genetic deviation of HC.

CONCLUSIONS

Measured against expected values derived from covariates of ASD subjects, statistical outliers for HC were uncommon. HC is a strongly heritable trait, and population norms for HC would be far more accurate if covariates including genetic ancestry, height, and age were taken into account. The association of diminishing IQ with absolute deviation from predicted HC values suggests HC could reflect subtle underlying brain development and warrants further investigation.

Compared to what? Early brain overgrowth in autism and the perils of population norms

BACKGROUND

Early brain overgrowth (EBO) in autism spectrum disorder (ASD) is among the best replicated biological associations in psychiatry. Most positive reports have compared head circumference (HC) in ASD (an excellent proxy for early brain size) with well-known reference norms. We sought to reappraise evidence for the EBO hypothesis given 1) the recent proliferation of longitudinal HC studies in ASD, and 2) emerging reports that several of the reference norms used to define EBO in ASD may be biased toward detecting HC overgrowth in contemporary samples of healthy children.

METHODS

Systematic review of all published HC studies in children with ASD. Comparison of 330 longitudinally gathered HC measures between birth and 18 months from male children with autism (n = 35) and typically developing control subjects (n = 22).

RESULTS

In systematic review, comparisons with locally recruited control subjects were significantly less likely to identify EBO in ASD than norm-based studies (p < .001). Through systematic review and analysis of new data, we replicate seminal reports of EBO in ASD relative to classical HC norms but show that this overgrowth relative to norms is mimicked by patterns of HC growth age in a large contemporary community-based sample of US children (n ~ 75,000). Controlling for known HC norm biases leaves inconsistent support for a subtle, later emerging and subgroup specific pattern of EBO in clinically ascertained ASD versus community control subjects.

CONCLUSIONS

The best-replicated aspects of EBO reflect generalizable HC norm biases rather than disease-specific biomarkers. The potential HC norm biases we detail are not specific to ASD research but apply throughout clinical and academic medicine.

Autism spectrum disorders and inborn errors of metabolism: an update

BACKGROUND

Autism spectrum disorder is characterized by social communicative deficits with restricted interests occurring in about 1% of the population. Although its exact cause is not known, several factors have been implicated in its etiology, including inborn errors of metabolism. Although relatively uncommon, these disorders frequently occur in countries with high rates of consanguinity and are often associated with behavioral problems, such as hyperactivity and aggression. The aim of this review is to examine the association of autism with these conditions.

METHOD

A computer-assisted search was performed to identify the most common inborn errors of metabolism associated with autism.

RESULTS

The following disorders were identified: phenylketonuria, glucose-6-phosphatase deficiency, propionic acidemia, adenosine deaminase deficiency, Smith-Lemli-Opitz syndrome and mitochondrial disorders, and the recently described branched chain ketoacid dehydrogenase kinase deficiency.

CONCLUSION

The risk of autistic features is increased in children with inborn errors of metabolism, especially in the presence of cognitive and behavioral deficits. We propose that affected children should be screened for autism.

Higher prevalence of autism in Taiwanese children born prematurely: a nationwide population-based study

The reported prevalence of autism in preterm and full-term children varies partially because of small sample sizes. Moreover, little is known about the specific factors that contribute to the risk of autism in preterm children. We aimed to compare the prevalence of autism in preterm and full-term children and to identify neonatal risk factors for autism in preterm children using a large national health system database. We analyzed data from 1078 early preterm (<28 weeks of gestation or birth weight<1000 g), 28,947 later preterm (28-36 weeks), and 1,104,071 full-term (≥ 37 weeks) children who were 8-11 years old in 2009. The descending order of prevalence was early preterm (2.2%), later preterm (1.3%), and full-term (0.6%). The prevalence of autism was approximately 2-4 times higher in preterm children than in children born at full-term. The male-female ratio (4:1) in preterm and full-term children was not significantly different. Most of the children were first diagnosed with autism between 3 and 6 years old. Preterm children with autism were not diagnosed earlier than were full-term children. Regression analysis showed that male gender, a very low birth weight, and neonatal cerebral dysfunction were risk factors for autism in the preterm group. We conclude that autism is more prevalent in preterm children. Preventing extremely preterm birth and significant early brain insults may be helpful in reducing the risk of autism in preterm children.