Children from families with a history of brain conditions are at higher risk for autism, according to a new study in Sweden. The study also found that the more closely related the family members are with these conditions, the higher the risk of autism is for the child.
The study, which examined family histories of epilepsy, attention deficit hyperactive disorder (ADHD), schizophrenia, and other conditions, was led by Brian Lee, an associate professor of epidemiology and biostatistics at Drexel University in Philadelphia. According to a report this month by Spectrum, Lee and his team examined records of 10,920 children with autism enrolled in the Stockholm Youth Cohort, an ongoing study of children from the Swedish city of Stockholm. The researchers also examined the records of 556,516 non-autistic children enrolled in the study.
Through national registries, the researchers examined over 8 million relatives, and the diagnoses of those relatives. They concluded that children with a first-degree relative, such as a sibling or parent, with a brain condition, had 4.7 times the usual risk of autism and a 7.6 times greater risk of having both autism and an intellectual disability. The researchers also found that the risk for autism decreases the greater the genetic distance between the child and the affected family member increases. According to the study, the 8,354 children who only have autism, but not an intellectual disability, are more likely to have a relative with a brain condition than the 2,566 children who have autism and an intellectual disability.
According to the study, children with a parent or sibling with autism are nine times more likely to have autism themselves, and are 4.1 times more likely to have both autism and an intellectual disability. Children with a parent or sibling with autism and an intellectual disability have 14.2 times the typical risk of having both, and 3.8 times the odds of having only autism.
Lee and his team are currently analyzing records in Denmark’s national registries to explore the relationship between autism and family histories of brain conditions, and other health issues.