About 20% of younger siblings of children with Autism Spectrum Disorder (ASD) will develop the condition by age 3. A new study by Yale School of Medicine researchers has found that 57% of these younger siblings who later develop the condition already showed symptoms at age 18 months. Chawarska said what was most interesting to the research team was that different patterns of behaviors at 18 months may be predictive of ASD later on. In about 50% of siblings, a combination of poor eye contact and lack of communicative gestures or imaginative play is most strongly associated with later ASD diagnosis. In a small percentage of those later diagnosed with ASD, eye contact may be relatively normal, but they begin to display early signs of repetitive behaviors and have limited non-verbal communication skills. “So not only do the behavioral symptoms appear at different ages, but different combinations of early symptoms may predict the diagnostic outcome,” Chawarska added. “Linking these developmental dynamics with underlying neurobiology may advance our understanding of causes of ASD and further efforts to personalize treatment for ASD by tailoring it to specific clinical profiles and their developmental dynamics.”
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