Diagnosis

Researchers identify how PCBs may alter in utero, neonatal brain development

Source: 
PLoS-Biology, Pessah, et al
Date Published: 
April 2009
Year Published: 
2009

In three new studies — including one appearing in the Public Library of Science - Biology (PLoS - Biology) — UC Davis researchers provide compelling evidence of how low levels of polychlorinated biphenyls (PCBs) alter the way brain cells develop.

The findings could explain at last — some 30 years after the toxic chemicals were banned in the United States — the associations between exposure of the developing nervous system to PCBs and behavioral deficits in children.

 

Peripheral Biomarkers in Autism: Secreted Amyloid Precursor Protein-Alpha as a Probably Key Player in Early Diagnosis

Source: 
Inter. Journal Clinical Exp. Medicine, Bailey, Giunta, et al
Date Published: 
2008
Year Published: 
2008

Autism is a pervasive developmental disorder characterized by impairments in socialization and communication. There is currently no single molecular marker or laboratory tool capable of diagnosing autism at an early age. The purpose of this study is to explore the plausible use of peripheral biomarkers in the early diagnosis of autism via a sensitive ELISA. Here, we measured plasma secreted amyloid precursor protein alpha (sAPP-alpha) levels in autistic and aged-matched control blood samples and found a significantly increased level of sAPP-alpha in 60% of the known autistic children. We then tested 150 human umbilical cord blood (HUCB) samples and found significantly elevated levels of plasma sAPP-alpha in 10 of 150 samples. As an additional confirmatory measure, we performed Western blot analysis on these samples which consistently showed increased sAPP-alpha levels in autistic children and 10 of 150 HUCB samples; suggesting a group of autistic patients which could be identified in early childhood by levels of sAPP-alpha. While there is need for further studies of this concept, the measurement of sAPP-alpha levels in serum and human umbilical cord blood by ELISA is a potential tool for early diagnosis of autism

Can Children with Autism Recover? If so, How?

Source: 
Neuropsychology Review, Helt, Kelley, et al
Date Published: 
2008
Year Published: 
2008

Although Autism Spectrum Disorders (ASD) are generally assumed to be lifelong, we review evidence that between 3% and 25% of children reportedly lose their ASD diagnosis and enter the normal range of cognitive, adaptive and social skills. Predictors of recovery include relatively high intelligence, receptive language, verbal and motor imitation, and motor development, but not overall symptom severity. Earlier age of diagnosis and treatment, and a diagnosis of Pervasive Developmental Disorder-Not Otherwise Specified are also favorable signs. The presence of seizures, mental retardation and genetic syndromes are unfavorable signs, whereas head growth does not predict outcome. Controlled studies that report the most recovery came about after the use of behavioral techniques. Residual vulnerabilities affect higher-order communication and attention. Tics, depression and phobias are frequent residual co-morbidities after recovery. Possible mechanisms of recovery include: normalizing input by forcing attention outward or enriching the environment; promoting the reinforcement value of social stimuli; preventing interfering behaviors; mass practice of weak skills; reducing stress and stabilizing arousal. Improving nutrition and sleep quality is non-specifically beneficial.

Absence of Preferential Looking to the Eyes of Approaching Adults Predicts Level of Social Disability in 2-year old toddlers with Autism Spectrum Disorder

Source: 
Archives of General Psychiatry, Jones, Carr, et al
Date Published: 
2008

Looking at the eyes of others is important in early social development and in social adaptation throughout one's life span. Our results indicate that in 2-year-old children with autism, this behavior is already derailed, suggesting critical consequences for development but also offering a potential biomarker for quantifying syndrome manifestation at this early age.

Variation in Season of Birth in Singleton and Multiple Births Concordant for Autism Spectrum Disorders

Source: 
Paediatric Pernatal Epidemiology, Lee, Newschaffer
Date Published: 
2008
Year Published: 
2008

Patterns of seasonal variation in births in some neuropsychiatric conditions have been found in previous research; however, no study to date has examined these disorders for seasonal variation in singletons and multiple births separately. This study aimed to determine whether the birth date distribution for individuals with autism spectrum disorders (ASD), including singletons and multiple births, differed from the general population. Two ASD case groups were studied: 907 singletons and 161 multiple births concordant for ASD. Two control groups were obtained from registered births of singletons and multiples. Results of the non-parametric time-series analyses, where day of birth was used, suggested there were three peaks in ASD singletons and ASD concordant multiple births. Roughly, the peaks were in April, June and October for singletons and about 2-4 weeks earlier in multiples. Results from multivariable Poisson regression, where month of birth was used, indicated that ASD concordant multiple births in males tended to be higher than expected in March, May and September (with borderline statistical significance), but were 87% less in December (P < 0.05), as compared with January. Overall, the patterns of relative risk estimates from Poisson regression are similar to findings from the non-parametric time-series approach, but are not exactly congruent. It is important to note that indications of seasonality may be sensitive to the selection of time cut-points and therefore an arbitrary binning of time can either mask existing trends or falsely indicate the presence of a trend. The presence of seasonal trends in ASD singletons and concordant multiple births suggests a role for non-heritable factors operating during the pre- or perinatal period, even among cases with a genetic susceptibility.

Racial/Ethnic Disparities in the Identification of Children with Autism Spectrum Disorders

Source: 
American Journal of Public Health, Mandell, Wiggins, et al
Date Published: 
2008
Year Published: 
2008

Fifty-eight percent of children had a documented autism spectrum disorder. In adjusted analyses, children who were Black (odds ratio [OR] = 0.79; 95% confidence interval [CI] = 0.64, 0.96), Hispanic (OR = 0.76; CI = 0.56, 0.99), or of other race/ethnicity (OR = 0.65; CI = 0.43, 0.97) were less likely than were White children to have a documented ASD. This disparity persisted for Black children, regardless of IQ, and was concentrated for children of other ethnicities when IQ was lower than 70.

Significant racial/ethnic disparities exist in the recognition of ASD. For some children in some racial/ethnic groups, the presence of intellectual disability may affect professionals' further assessment of developmental delay. Our findings suggest the need for continued professional education related to the heterogeneity of the presentation of ASD.

Screening Strategies for Autism Spectrum Disorders in Pediatric Primary Care

Source: 
Journal of Developmental and Behavioral Pediatrics, Pinto-Martin, Young, Mandell, Poghosyan, Giarelli, Levy
Date Published: 
2008
Year Published: 
2008

Two strategies have been proposed for early identification of children with autism spectrum disorders (ASD): (1) using a general screening tool followed by an ASD-specific screening tool for those who screen positive on the former or (2) using an ASD-specific tool for all children. The relative yield of these two strategies has not been examined. 

This study compared the number of children identified at risk for ASD at their well child visits between the ages of 18 and 30 months using a general developmental screening tool and an autism-specific screening tool. 

The PEDS missed the majority of children who screened positive for ASD on the M-CHAT, suggesting that these two tools tap into very different domains of developmental concerns. The findings support the use of an ASD-specific tool for all children in conjunction with regular standardized developmental screening.

Continuing Increases in Autism Reported to California’s Developmental Services System: Mercury in Retrograde

Source: 
Archives of General Psychiatry, Schechter, Grether
Date Published: 
2008
Year Published: 
2008

California Department of Developmental Services (DDS) data do not show any recent decrease in autism in California despite the exclusion of more than trace levels of thimerosal from nearly all childhood vaccines. The DDS data do not support the hypothesis that exposure to thimerosal during childhood is a primary cause of autism.