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Baby Sibling Study Finds Strong Predictors of Autism at 18 Months

Study identifies behavior patterns that predict autism with near 80 percent certainty, flags opportunity for early intervention
October 15, 2014

Study identifies behavior patterns that predict autism with near 80 percent certainty, flags opportunity for early intervention 

(Oct 15, 2014) Researchers with Autism Speaks Baby Siblings Research Consortium have identified three behavior patterns that flag a near 80 percent likelihood that a “baby sib” of a child with autism spectrum disorder (ASD) will likewise develop autism.

“While the majority of siblings of children with ASD will not develop the condition themselves, for those who do, one of the key priorities is finding more effective ways of identifying and treating them as early as possible,” says lead author Katarzyna Chawarska, of Yale University School of Medicine. “Our study reinforces the need for repeated diagnostic screening in the first three years of life to identify individual cases as soon as behavioral symptoms are apparent.” Dr. Chawarska directs Yale’s Toddler Developmental Disabilities Clinic and its Early Social Cognition Lab.

The report appears in the Journal of the American Academy of Child & Adolescent Psychiatry.

Previous research by the consortium found that around 20 percent (1 in 5) of the baby siblings of children with autism will develop autism by age 3. Another 20 percent, a later study found, will develop autism-related issues that warrant therapy but don’t meet all the criteria for an autism diagnosis.

The group’s new study is the first large, multi-site investigation to identify behaviors that distinguish baby sibs who will develop autism from those who will develop typically and those who will develop some autism-related problems.

The authors analyzed detailed behavioral information on 719 toddlers from eight BSRC sites. They identified three distinct behavior patterns that predicted a high likelihood – around 80 percent – that a child would go on to develop autism.

These behavior patterns included:

* Poor eye contact combined with no communicative gestures such as pointing

* Poor eye contact combined with no imaginative play

* Repetitive behaviors combined with no giving (offering food, toys, etc.)

Importantly, not all of the children who would go on to develop autism showed one of these three behavior patterns at 18 months. In fact, the researchers saw one of these patterns in only 57 percent of the toddlers later diagnosed with autism.

The distinct patterns suggest different developmental pathways to autism, the researchers conclude. Understanding such different pathways, in turn, could lead to more-targeted treatments for subtypes of autism, they add.

“These findings are important for helping us identify children in need of early intervention,” agrees Paul Wang, Autism Speaks head of medical research. A developmental pediatrician, Dr. Wang was not directly involved in the study. “However it’s also important to note that no single behavior always predicted autism. Conversely, no single behavior always predicted typical development. This underscores the complexity of early behaviors of children at risk for autism and, so, the need careful and thorough evaluation by professionals.”