Recurrence risk for autism spectrum disorders examined for full, half siblings

August 19, 2013

A Danish study of siblings suggests the recurrence risks for autism spectrum disorders (ASDs) varied from 4.5 percent to 10.5 percent depending on the birth years, which is higher than the ASD risk of 1.18 percent in the overall Danish population, according to a study published by JAMA Pediatrics.

ASDs are that are characterized by difficulties in and communication and also include and narrow interests. Childhood autism (CA) accounts for about 30 percent of all ASD cases and the prevalence of ASDs has increased during the last two decades, according to the study background.

Therese K. Grønborg, M.Sc., of Aarhus University, Denmark, and colleagues conducted a population-based study in Denmark of all children (about 1.5 million) born between 1980 and 2004. They identified a maternal sibling group derived from mothers with at least two children and a paternal sibling group derived from fathers with at least two children.

"To date, this is the first population-based study to examine the recurrence risk for (ASDs), including time trends, and the first study to consider the ASDs recurrence risk for full- and half-siblings," the authors note in the study.

The study results suggest an almost seven-fold increase in ASDs risk if an older sibling had an ASD diagnosis compared with no ASD diagnoses in older siblings. In children with the same mother, the adjusted relative recurrence risk of 7.5 in full siblings was significantly higher than the risk of 2.4 in half siblings. In children with the same father, the adjusted relative recurrence risk was 7.4 in full siblings and significant, but no statistically significant increased risk was observed among paternal half siblings, the results also indicate.

"The difference in the recurrence risk between full and half siblings supports the role of genetics in ASDs, while the significant in maternal half- may support the role of factors associated with pregnancy and the maternal intrauterine environment in ASDs," the study concludes.

Explore further: Study shows delays in siblings of children with autism spectrum disorders

More information: JAMA Pediatr. Published online August 19, 2013. DOI: 10.1001/jamapediatrics.2013.2259

Related Stories

Study explains functional links between autism and genes

June 21, 2012

A pioneering report of genome-wide gene expression in autism spectrum disorders (ASDs) finds genetic changes that help explain why one person has an ASD and another does not. The study, published by Cell Press on June 21 ...

Study of half siblings provides genetic clues to autism

April 17, 2012

(Medical Xpress) -- When a child has autism, siblings are also at risk for the disorder. New research from Washington University School of Medicine in St. Louis shows that the genetic reach of the disorder often extends to ...

Recommended for you

Autism biomarker seen as boon for new treatments

January 11, 2017

Researchers at the UCLA Center for Autism Research and Treatment have identified a signature brain-wave pattern for children with autism spectrum disorder related to a genetic condition known as Dup15q syndrome. The research ...

Lab confirms vitamin D link to autism traits

December 14, 2016

Researchers at The University of Queensland's Queensland Brain Institute have found a link between vitamin D deficiency in pregnancy and increased autism traits.

Neuromotor problems at the core of autism, study says

December 12, 2016

Rutgers neuroscientists have established that problems controlling bodily movements are at the core of autism spectrum disorders and that the use of psychotropic medications to treat autism in children often makes such neuromotor ...

Mutations in life's 'essential genes' tied to autism

December 12, 2016

Genes known to be essential to life—the ones humans need to survive and thrive in the womb—also play a critical role in the development of autism spectrum disorder (ASD), suggests a new study from Penn Medicine geneticists ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.