Gender

A Genotype Resource for Postmortem Brain Samples from the Autism Tissue Program

Source: 
Autism Res, Wintle et al.
Date Published: 
April 2011
Year Published: 
2011

The Autism Tissue Program (ATP) is a postmortem brain tissue program created by the National Alliance for Autism Research (NAAR) for the purpose of supplying research scientists with neurological tissue samples of deceased Autistic individuals. Scientists, however, are not supplied with tissue samples from any other parts of the deceased individual, leading to frustration over genotype/phenotype verification. In this study, scientists from the Hospital for Sick Children in Toronto verify the ethnicity and gender of a certain sample, and provide an algorithmic verification system for other researchers looking to provide accurate research into the genotype/phenotype makeup of their sample.

Researchers Reveal First Autism Candidate Gene That Demonstrates Sensitivity to Sex Hormones

Source: 
Journal of Molecular Psychiatry, Hu et al.
Date Published: 
March 2011
Year Published: 
2011

 

George Washington University researchers have found that male and female sex hormones regulate expression of an important gene in neuronal cell culture through a mechanism that could explain not only higher levels of testosterone observed in some individuals with autism, but also why males have a higher incidence of autism than females.

The gene, RORA, encodes a protein that works as a "master switch" for gene expression, and is critical in the development of the cerebellum as well as in many other processes that are impaired in autism. Dr. Hu's earlier research found that RORA was decreased in the autistic brain. In this study, the research group demonstrates that aromatase, a protein that is regulated by RORA, is also reduced in autistic brains.

This is significant because aromatase converts testosterone to estrogen. Thus, a decrease in aromatase is expected to lead in part to build up of male hormones that, in turn, further decrease RORA expression, as demonstrated in this study using a neuronal cell model. On the other hand, female hormones were found to increase RORA in the neuronal cells. The researchers believe that females may be more protected against RORA deficiency not only because of the positive effect of estrogen on RORA expression, but also because estrogen receptors, which regulate some of the same genes as RORA, can help make up for the deficiency in RORA.

Researchers Reveal First Autism Candidate Gene That Demonstrates Sensitivity to Sex Hormones

Source: 
Science Daily
Date Published: 
February 17, 2011
Abstract: 

George Washington University researcher, Dr. Valerie Hu, Professor of Biochemistry and Molecular Biology, and her team at the School of Medicine and Health Sciences, have found that male and female sex hormones regulate expression of an important gene in neuronal cell culture through a mechanism that could explain not only higher levels of testosterone observed in some individuals with autism, but also why males have a higher incidence of autism than females.

Smoking during Pregnancy affects Myelin Genes in Offspring

Source: 
Science Daily
Date Published: 
November 16, 2010
Abstract: 

Smoking during pregnancy may interfere with brain development. New animal research shows maternal smoking affects genes important in the formation and action of a fatty brain substance called myelin that insulates brain cell connections. The finding may explain why the children of mothers who smoked during pregnancy are more likely to develop attention deficit hyperactivity disorder, depression, autism, drug abuse, and other psychiatric disorders.

Neonatal Jaundice Linked to Autism

Source: 
MedPage Today
Date Published: 
October 11, 2010
Abstract: 

Full-term neonates with jaundice are at greatly increased risk of later being diagnosed with a disorder of psychological development, a Danish study found. Neonatal jaundice typically is caused by increased bilirubin production and inadequate liver excretory function. Recent research has suggested that even moderate bilirubin exposure in very young children can be harmful, possibly leading to impairments in their development. They found that jaundice was more common among boys, infants born preterm, infants with congenital malformations, and low-birthweight infants.

New Genetic Risk Factor for Both Autism and Schizophrenia

Source: 
Science Daily
Date Published: 
November 4, 2010
Abstract: 

Researchers have uncovered a prominent genetic risk factor for autism spectrum disorders and schizophrenia is a small genomic deletion. Remarkably, they found the same deletion on chromosome 17 in 24 separate patients. This CNV was absent in 52,448 controls, making the finding statistically significant. Someone with this deletion is 13.58 times more likely to develop ASD or schizophrenia than is someone lacking this CNV. This gene mutation is also known to cause kidney disease (renal cysts and diabetes syndrome, RCAD).

Language Delays Found in Siblings of Children with Autism

Source: 
Medical News Today
Date Published: 
October 3, 2010
Abstract: 

A new study, led by researchers at Washington University School of Medicine in St. Louis, found mild traits, not strong enough to provoke a diagnosis of autism, seem to be present in the siblings of affected children at significantly higher rates than seen in the general population.

Siblings of children with autism have more frequent language delays and other subtle characteristics of the disorder than previously understood. Girls also may be mildly affected more often than recognized in the past.

Link to Autism in Boys Found in Missing DNA

Source: 
Science Daily
Date Published: 
September 15, 2010
Abstract: 

If a boy's X-chromosome is missing the PTCHD1 gene or other nearby DNA sequences, they will be at high risk of developing ASD or intellectual disability. Girls are different in that, even if they are missing one PTCHD1 gene, by nature they always carry a second X-chromosome, shielding them from ASD.

Prenatal and Infant Exposure to Thimerosal from Vaccines and Immunoglobulins and Risk of Autism

Source: 
Pediatrics, Price et al
Date Published: 
September 2010
Year Published: 
2010

This new study in the journal of Pediatrics indicated that there was no increased risk of Autism Spectrum Disorder associated with receipt of thimerosal-containing vaccines. The study also found no increased risk for any of the subtypes of Autism Spectrum Disorder, including ASD with regression.  In addition, it found no increased risk of Autism Spectrum Disorder associated with prenatal exposure to thimerosal.  No significant differences in exposure effects were found between boys and girls for any of the ASD outcomes; there was no evidence that higher prenatal exposure exacerbated the effects of post-natal exposure; and there was no evidence that concurrent ethylmercury exposure was associated with ASD. In addition, there was no substantive difference in the association between thimerosal exposure and risk for ASD among children with an older sibling with autism and those without an older sibling with autism.

Changes in Autism Spectrum Disorder Prevalance in 4 Areas in the United States

Source: 
Diability and Health Journal, Rice et al
Date Published: 
July 2010
Year Published: 
2010

Study sought to describe autism spectrum disorder (ASD) population characteristics and changes in identified prevalence across 3 time periods.  Children with a potential ASD were identified through records abstraction at multiple sources with clinician review based on Diagnostic and Statistical Manual (DSM-IV-TR) criteria. Multisite, population-based data from the Autism and Developmental Disabilities Monitoring (ADDM) Network were analyzed from areas of Arizona (AZ), Georgia (GA), Maryland (MD), and South Carolina (SC). Participants were 8-year-old children (born in 1992, 1994, or 1996) in 2000, 2002, or 2004 (and children born in 1988 residing in metropolitan Atlanta in 1996) who had been evaluated for a variety of developmental concerns at education and/or health sources.  There was a trend toward increase in identified ASD prevalence among 8-year-old children who met the surveillance case definition in 3 of the 4 study sites from 2000 to 2004. Some of the observed increases are due to improved ascertainment; however, a true increase in ASD symptoms cannot be ruled out. These data confirm that the prevalence of ASDs is undergoing significant change in some areas of the United States and that ASDs continue to be of urgent public health concern.