Risk Linked to Those Who Have Co-Occurring Intellectual Disability and/or Birth Defects
A study out of Sweden has discovered that individuals with autism spectrum disorder (ASD) who have comorbid intellectual disability (ID) and/or birth defects were at a higher risk of developing cancer in early life (before age 30) compared to those without ASD. This new research involved performing a population-based cohort study, which included 2.3 million people born to mothers of Nordic countries from 1987-2013 in Sweden, with follow up through 2016 (up to age 30). Individuals with ASD were identified through the Swedish National Patient Register. The study also included a sibling comparison to address familial confounding and a genetic correlation analysis using GWAS summary statistics to address confounding due to potential polygenetic pleiotropy between ASD and cancer. After the study’s data was analyzed, the results showed an overall increased risk of any cancer for individuals with ASD (OR 1.3, 95% CI 1.2-1.5) compared to those without the disorder. The association for any type of cancer was primarily noted for narrowly defined autistic disorder (OR 1.7, 95% CI 1.3-2.1) and ASD with comorbid birth defects (OR 2.1, 95% CI 1.5-2.9) or both birth defects and intellectual disability (OR 4.8, 95% CI 3.4-6.6). Additionally, an association for ASD with comorbid intellectual disability (OR 1.4, 95% CI 0.9-2.1) was identified but found not statistically significant. Interestingly, ASD alone (i.e., without comorbid intellectual disability or birth defects) was not associated with an increased risk of any cancer. The sibling comparison and genetic correlation analysis demonstrated little evidence of familial confounding or confounding due to polygenetic pleiotropy between ASD and cancer. The study’s authors ended their paper with a call for additional research on specific cancer types among individuals with ASD and ID and/or birth defects. They also recommend a follow-up study to examine the risk of cancers diagnosed later in life for individuals with ASD, regardless of comorbidities since cancers diagnosed in later life likely differ from those diagnosed in early life.
