Table 3. An Overview of the Research Items.

Author	Type of Study	Purpose/Topic	Subjects	Key Findings
Dai et al.	Case-control human trial by comparing cohorts.	-Basal OT levels are higher in WS. -An increase in basal OT is related to social function. -WS may cause exaggerated OT release to emotional stimuli.	-WS cohort = 13 individuals (7 females aged 22–42, and 6 males aged 19–38). -Typical controls = 9 individuals (4 females aged 20–45, 4 males aged 19–40).	-The median basal OT level is 3-times higher in WS. -OT levels are higher in WS at all-time points during interventions. -Approachability correlates significantly with basal OT. -Maladaptive behaviors significantly negatively correlate with basal OT levels. -Basal OT does not correlate with FSIQ in WS. -Changes in OT, to emotional stimulus exhibit both greater variability and greater increases in WS.
Kimura et al.	Case-control human trial by comparison of cohorts and existing data.	-Show irregular OXTR levels in WS. -Investigate OXTR expression in WS compared to healthy controls.	1. For gene expression analysis: -WS cohort = 15 patients TC=15 age–sex–race balanced Japanese controls. 2. For DNA methylation analysis: -Set A: WS cohort = 34 patients TC = 34 age–sex–race balanced Japanese controls -Set B: WS cohort = 20 pediatric patients TC = 15 age-balanced controls of European origin.	-WS patients showed significantly lower expression of OXTR. -No significant correlation between the expression levels of OXTR and total SRS-T scores. -OXTR expression was downregulated in WS compared to controls, although no clear correlation between expression levels and severity of social function was found. -WS patients have significantly higher methylation at three CpG sites around the transcriptional start site. -The methylation observed in the blood correlated with the brain. Three CpG sites (cg25140571, cg00247334, and cg17036624) were significantly correlated with the superior temporal gyrus.
Haas et al.	Case-control human trial with comparison to existing patient data.	-Show if the irregular expression of OXTR alters OT functioning in WS.	-WS Cohort = 8 patients (mean age = 4.87 years; standard deviation = 2.10). -Control Cohort = 9 age and sex-matched healthy individuals.	-WS subjects exhibited greater expression of OXTR. -The variance between groups was statistically significant for OXTR expression. -The abnormal function of the OT system in WS, may in part be influenced by overexpression of OXTR.
Nygaard et al.	Case-control animal trial by comparing cohorts.	-Compare blood OT levels of WS with the control group. -Investigate whether OXTR expression differs in WS versus wild-type mice across the brain.	1. The cohort for blood OT test: WS = 13 mice, TC = 11 WT male mice from 8 independent litters. 2. The cohort to evaluate OXTR expression: WS = 14 mice (5 female, 9 male) TC = 22 (12 female, 10 male) mice from 11 independent litters.	-No significant differences in OT levels between genotypes. -Measured areas of where OT has been shown to affect sociability or memory, no significant differences in OXTR binding between genotypes within regions of interest.