At present, there are no consistent evidence for association between any specific OXTR SNP and social behaviors in the literature. There are however several reports of nominal associations to various social behaviors. In this study we have chosen polymorphisms located in as well as up- and downstream of the OXTR with a relatively even distribution that have been associated to risk of autism or other aspects of social behaviors in at least in one previous paper (with the exception of the non-synonomus SNP rs4686302). Proposed association, references and further information about the studied SNPs are found in Table 1. Genotyping of SNPs rs75775, rs1488467, rs4564970, rs53576, rs237897, rs237887, rs11720238 was performed by KBioscience (http://www.kbioscience.co.uk) using the KASPar chemistry, which is a competitive allele specific PCR SNP genotyping system using FRET quencher cassette oligos (http://www.kbioscience.co.uk/genotyping/genotyping-chemistry.htm). The remaining five SNPs rs4686302, rs2254298, rs2268493, rs1042778 and rs7632287 were genotyped using commercially available 5′ nuclease (TaqMan) assays on an ABI Prism 7900HT instrument (Applied Biosystems, Foster City, CA, USA).
