Author: Sara Webb, PhD

Twins and Autism

Today we discuss the topic of twins and autism with Dr. Sara Jane Webb, Associate Professor at the University of Washington and Psychiatry & Behavioral Sciences, Seattle Children’s Research Institute

Lynn: If one identical (monozygotic) twin has autism, what is the likelihood the other will? If one fraternal (dizygotic) twin has autism, what is the likelihood the other will?

Dr. Webb: Concordance in ASD diagnosis (the probability that both will have it) is observed in monozygotic (MZ) twin pairs at rates of 60-90%, whereas rates among dizygotic (DZ) twins are estimated at 3-31%. (Bailey et al., 1995; Folstein & Rutter, 1977; Hallmayer et al., 2011; Ronald & Hoekstra, 2011; Rutter, 2005). The wide range for each reported rate may be attributable to differences in how ASD was defined and diagnostic measurement differences. That is, some studies used clinical diagnosis of autism as conceptualized in the 1970s and others used specific diagnostic criteria and Read full post »

Girls and Autism

We’re excited to post the following blog on a topic we don’t hear much about – girls and autism. Because they are in the minority when it comes to autism diagnosis, girls have not received attention as a unique subset of people with autism. That seems to be changing! Here’s what two of our colleagues at the University of Washington Autism Center, Sara Webb, PhD, and Katy Ankenman, MSW, shared with us about their study on girls and autism.

It is common knowledge that autism spectrum disorder (ASD) is diagnosed more often in boys than girls. Current prevalence rates tell us that boys are at higher risk of ASD as the ratio of boys to girls with ASD is about 4.5:1. The Read full post »