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 »