Investigating associations between birth order and autism diagnostic phenotypes.
Gail A AlvaresMelissa K LicariPaul G StevensonKeely BebbingtonMatthew N CooperEmma J GlassonDiana Weiting TanMirko UljarevicKandice J VarcinJohn WrayAndrew J O WhitehousePublished in: Journal of child psychology and psychiatry, and allied disciplines (2020)
These findings demonstrate for the first time an association between increasing birth order and variability in ASD clinical phenotypes at diagnosis, with potential evidence of reproductive curtailment in children without siblings. Taken together, these findings have significant implications for advancing understanding about the potential mechanisms that contribute to heterogeneity in ASD clinical presentations as a function of birth order and family size.