Biomarkers

Antibodies Against Fetal Brain in Sera of Mothers with Autistic Children

Source: 
Journal of Neuroimmunology, Singer, Morris, Gause, Gillin, Crawford, Zimmerman

Serum antibodies in 100 mothers of children with autistic disorder (MCAD) were compared to 100 age-matched mothers with unaffected children (MUC) using as antigenic substrates human and rodent fetal and adult brain tissues, GFAP, and MBP. MCAD had significantly more individuals with Western immunoblot bands at 36 kDa in human fetal and rodent embryonic brain tissue. The density of bands was greater in fetal brain at 61 kDa. MCAD plus developmental regression had greater reactivity against human fetal brain at 36 and 39 kDa. Data support a possible complex association between genetic/metabolic/environmental factors and the placental transfer of maternal antibodies in autism.

Association Between Microdeletion and Microduplication at 16p11.2 and Autism

Source: 
New England Journal of Medicine, Weiss, Shen, et al
Date Published: 
2008

We have identified a novel, recurrent microdeletion and a reciprocal microduplication that carry substantial susceptibility to autism and appear to account for approximately 1% of cases. We did not identify other regions with similar aggregations of large de novo mutations. Among the AGRE families, we observed five instances of a de novo deletion of 593 kb on chromosome 16p11.2. Using comparative genomic hybridization, we observed the identical deletion in 5 of 512 children referred to Children's Hospital Boston for developmental delay, mental retardation, or suspected autism spectrum disorder, as well as in 3 of 299 persons with autism in an Icelandic population; the deletion was also carried by 2 of 18,834 unscreened Icelandic control subjects. The reciprocal duplication of this region occurred in 7 affected persons in AGRE families and 4 of the 512 children from Children's Hospital Boston. The duplication also appeared to be a high-penetrance risk factor.

A Common Genetic variant in the neurexin superfamily member CNTNAP2 increases Familial Risk of Autism

Source: 
American Journal of Human Genetics, Arking, Cutler, et al
Date Published: 
December 2008
Year Published: 
2008

Autism is a childhood neuropsychiatric disorder that, despite exhibiting high heritability, has largely eluded efforts to identify specific genetic variants underlying its etiology. We performed a two-stage genetic study in which genome-wide linkage and family-based association mapping was followed up by association and replication studies in an independent sample. We identified a common polymorphism in contactin-associated protein-like 2 (CNTNAP2), a member of the neurexin superfamily, that is significantly associated with autism susceptibility. Importantly, the genetic variant displays a parent-of-origin and gender effect recapitulating the inheritance of autism.

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

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.