FROM AUTISM RESEARCH
High-risk siblings of children with autism spectrum disorder (ASD) show lower levels of initiating joint attention (IJA) than do low-risk siblings of children without ASD, according to Devon N. Gangi, Ph.D., and his associates.
“Early deficits in [IJA], a form of referential communication involving the use of gaze and gesture to coordinate attention between social partners and objects, are a core feature of ASD,” the researchers noted.
“We aimed to refine our understanding of heterogeneity in early behavior relevant to ASD by examining the role of common genetic variants,” they wrote. “To our knowledge, this is the first investigation of these genetic variants in relation to joint attention in siblings at risk for ASD.”
In the preliminary analysis, among the children with 7-repeat allele in the DRD4 genotype, high-risk siblings exhibited lower levels of IJA (M = –0.52, SD = 0.75) than did low-risk siblings (M= 0.73, SD = 1.01), (t  = 3.62, P = .001). Also, in the DRD2 genotype, there was a main effect of group status, (P = .01), with high-risk siblings (M = –0.13, SD = 0.84) exhibiting lower levels of IJA than those of low-risk siblings (M = 0.29,SD = 0.86), the researchers wrote.
“Among high-risk siblings, early behavior often predicts diagnosis, but these patterns of prediction are not clear,” they noted.
The study also examined dopamine scores in both high- and low-risk siblings in correlation with IJA. Read the study in Autism Research ( doi: 10.1002/aur.1623 ).