Familial Recurrence of Autism: Updates From the Baby Siblings Research Consortium

Area of Science:

• Genetics and Genomics
• Developmental Neuroscience
• Public Health

Background:

• Autism spectrum disorder (ASD) shows significantly higher prevalence in children with an autistic sibling.
• Previous prospective studies indicated elevated familial recurrence rates for ASD.
• This study provides updated familial ASD recurrence estimates using a multinational infant sibling cohort.

Purpose of the Study:

• To estimate the familial recurrence rate of autism spectrum disorder (ASD) in infants with an older autistic sibling.
• To identify predictors of ASD recurrence within families.
• To update recurrence risk figures based on a large, multinational prospective study.

Main Methods:

• Data collected from 1605 infants across 18 international sites of the Baby Siblings Research Consortium.
• Infants were followed from early life to 3 years for ASD classification.
• Hierarchical generalized linear modeling analyzed recurrence predictors, accounting for site-specific effects.

Main Results:

• The familial ASD recurrence rate was 20.2%, not significantly different from prior estimates.
• Male infant sex, having more than one older affected sibling, and female probands were significant predictors of recurrence.
• Factors such as race and maternal education also showed associations with recurrence.

Conclusions:

• Familial ASD recurrence rates in infant sibling studies have remained consistent since 2011.
• Infants at higher risk (male, female proband, multiple affected siblings, social inequities) warrant close monitoring and prompt diagnostic evaluation.
• Early identification and intervention are crucial for siblings of children with autism.