Familial Risk of Autism Reading Guide

Sandin et al. 2014 Reading Guide

Sandin, S., Lichtenstein, P., Kuja-Halkola, R., Larsson, H., Hultman, C. M., & Reichenberg, A. 

(2014). The familial risk of autism. Jama, 311(17), 1770-1777.

1.What is the main purpose of this article?       

• The main purpose of this article is to show the results of their study on the familial risk of autism by providing estimates of familial aggregation and heritability of Autism Spectrum Disorder.

2.The authors cite previous studies that have led to estimations about the effects of genetic factors for ASD at the population level. What reasons do the authors give to justify a closer look at the individual level?     

• Previous studies had limitations, including small sample size, limiting the reliability of the results.

3.What is a relative recurrence risk?     

• The relative recurrence risk (RRR) measures the recurrence of a disorder in relation to disease in families without any affected members but can be interpreted and compared between groups that may differ in disease prevalence.

• The relative recurrence risk for siblings is the risk of an autism diagnosis in a sibling of a child with autism compared with a sibling of a child without autism.

4.What were the main findings from this study?     

• The study was to determine the family clustering of ASD by estimating the relative recurrence risk within families and assess the importance of genetic vs. environment factors associated with ASD.

• The RRR remained stable after adjustment for sex, parental psychiatric history, and parental age.

• There was no statistically significant difference in RRR between boys or girls or in RRR in participants with a male or female sibling. 

• Among children born in Sweden, the individual risk of ASD increased with increasing genetic relatedness. The heritability of ASD was estimated to be approximately 50%. These findings may inform the counseling of families with affected children.

5.The information in this article helps develop a more nuanced picture of the possible etiology of ASD. The authors conclude that this information can be used to counsel families of children affected with ASD. How might understanding the relative recurrence risk inform counseling of families?     

• Understanding the relative recurrence risk can inform the counseling of families by giving reason and scientific evidence behind the disorder and how only some of their children developed ASD.