Siblings

Mothers of Autistic Children Earn 56% Less Income, Study Says

Source: 
CBS News
Date Published: 
March 19, 2012
Abstract: 

On average, families with a child who has autism earn 28% less than those of a child without a health limitation; nearly $18,000 less per year.

New Research Suggests Birth Weight Plays A Role In Autism Spectrum Disorder

Source: 
Medical News Today
Date Published: 
January 23, 2012
Abstract: 

Although the genetic basis of autism is now well established, a growing body of research also suggests that environmental factors may play a role. Using a unique study design, a new study suggests that low birth weight is an important environmental factor contributing to the risk of autism spectrum disorder (ASD).

Genetic Heritability and Shared Environmental Factors Among Twin Pairs with Autism

Source: 
Archives of General Psychiatry
Date Published: 
November 2011
Year Published: 
2011

Recent research suggests that environmental factors may play a much greater role in autism risk than previously suspected and could even be more influential than genetic factors. These findings stem from a study of autism in twins, the largest of its kind, designed to model the genetic and environmental factors that contribute to the development of autism. Because identical twins share 100 percent of their DNA, researchers can assess the degree to which a disorder is genetic by studying the number of cases where both twins are affected (called concordance). Fraternal twins share 50 percent of their DNA, similar to siblings, so by comparing concordance rates among fraternal twins and siblings, researchers can study the influence of environmental factors, particularly those in the womb. In the study, researchers looked at concordance among 192 pairs of identical and fraternal twins and found that 77 percent of male identical twins and 50 percent of female twins were both affected by autism. Previous studies with smaller numbers of twins suggested a much greater genetic contribution, as high as 90 percent. The fraternal twins in the study had a 35 percent concordance rate – much lower than rates among identical twins but higher than rates among siblings, estimated to range from 3 to 19 percent. Using mathematical modeling, the researchers propose that environmental factors accounted for 55 percent of autism risk, while genetic heritability contributed less than 40 percent. The difference in rates among fraternal twins and siblings, who share similar amounts of DNA, suggests that environmental factors in the womb may be an important area of future study.

--IACC 2011 Summary of Advances in ASD Research

Autism Risk for Siblings Higher Than Expected

Source: 
New York Times - Well Blog
Date Published: 
August 16, 2011
Abstract: 

According to a recent study published in the journal of Pediatrics, the younger sibling of a child with autism has nearly 20 times greater risk of developing autism than a child in the general population.

Recurrence Risk for Autism Spectrum Disorders: A Baby Siblings Research Consortium Study

Source: 
Pediatrics, Ozonoff et al.
Date Published: 
August 2011
Year Published: 
2011

A study published August 15, 2011 in the journal Pediatrics found that infants with an older autistic sibling have a near 19 percent risk that they too will develop the disorder. The study is considered the largest autism study to follow infants for sibling recurrence.

Rare De Novo and Transmitted Copy-Number Variation in Autistic Spectrum Disorders

Source: 
Neuron
Date Published: 
June 9, 2011
Year Published: 
2011

A study of the genetic causes of autism confirmed that spontaneous or de novo mutations are present in a substantial number of families with only one child on the spectrum. These de novo mutations are not inherited from parents' DNA, arising instead in their egg or sperm or very early in embryonic development. Researchers compared the DNA of children with ASD to that of their unaffected sibling(s) and identified a diverse array of rare genetic abnormalities that may contribute to autism. Recent advances in technology have allowed researchers to identify genetic mutations on a finer scale than was previously possible. Some of thede novo mutations, known as copy number variations (CNVs) because they contain deleted or duplicated sections of DNA, were located in regions known to be associated with ASD, while others implicate new regions. Many of the mutations are thought to affect genes or gene networks involved in brain development. The study confirmed that these non-inherited CNVs are more common in children with ASD compared to their non-affected siblings; however, each unique variant is exceedingly rare, some found in only one family. In addition, researchers found evidence that inherited "ultrarare" genetic duplications may also contribute to autism. Based on the results of the study, the authors note that females have a greater resistance to autism from genetic causes, raising questions about the fate of female carriers. The study findings emphasize the diversity of rare genetic variations that contribute to ASD and suggest the possibility that a treatment for one form of autism may not have value for the majority of cases. The DNA samples analyzed in the study were part of the Simons Simplex Collection, a repository of over 1,000 families in the U.S. and Canada with only one child on the spectrum.

--IACC 2011 Summary of Advances in ASD Research

Gene Linked to Severity of Autism's Social Dysfunction Identified

Source: 
Science Daily
Date Published: 
April 7, 2011
Abstract: 

With the help of two sets of brothers with autism, Johns Hopkins scientists have identified a gene associated with autism that appears to be linked very specifically to the severity of social interaction deficits. The gene, GRIP1 (glutamate receptor interacting protein 1), is a blueprint for a traffic-directing protein at synapses -- those specialized contact points between brain cells across which chemical signals flow.

Autism Risk Linked To Space Between First And Second Pregnancy

Source: 
Medical News Today
Date Published: 
January 10, 2011
Abstract: 

A second child is three times more likely to be diagnosed with autism if they are born within twelve months of their siblings, compared to those born three or more years apart, researchers from the Lazarsfeld Center for the Social Sciences at Columbia University, New York revealed in the journal Pediatrics. The investigators gathered information on 660,000 second children born in California between 1992 to 2002.

Neural Signatures of Autism

Source: 
PNAS, Kaiser, Hudack, Schultz, Lee, Cheung, Berken, Deen, Pitskel, Sugrue, Voos, Saulnier, Ventola, Wolf, Klin, Vander Wyk, Pelphrey
Date Published: 
December 2010
Year Published: 
2010

These findings of this study hold far-reaching implications for our understanding of the neural systems underlying autism. Using FMRI to record the biological motion of children with autism spectrum disorder, unaffected siblings of children with ASD, and typically developing children, the study reveals three types of neural signatures: The study finds distinct brain responses to biological motion exhibited by typical developing children and unaffected siblings. This finding is particularly striking given the identical behavioral nature of these two groups.

Brain Scans Detect Autism's Signature

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

An autism study by Yale School of Medicine researchers using functional magnetic resonance imaging (fMRI) has identified a pattern of brain activity that may characterize the genetic vulnerability to developing autism spectrum disorder (ASD).

The team identified three distinct "neural signatures": trait markers -- brain regions with reduced activity in children with ASD and their unaffected siblings; state markers -- brain areas with reduced activity found only in children with autism; and compensatory activity -- enhanced activity seen only in unaffected siblings. The enhanced brain activity may reflect a developmental process by which these children overcome a genetic predisposition to develop ASD.