Prader-Willi Syndrome (PWS) is a genetically determined neurodevelopmental disorder which occurs in approximately 1 in 22000 births.

Parents of subjects with genetically confirmed PWS (participating in the First National Irish PWS study) were asked to fill in a demographic questionnaire, The Child Behaviour Checklist 6–18 (CBCL/6–18), Brief Symptom Inventory (BSI). The age, gender and IQ matched control group was collected through Special Schools.

Both groups (PWS and Controls) were comprised of 24 children. Internalizing problems score was higher in children with PWS than controls (T mean score (62.02 (SD = 10.17) vs. 58.13 (SD = 7.53) p < . 05). The comparison of PWS and control group along CBCL/6–18 syndromes profiles indicated that children with PWS had more sever somatic problems (mean T 63.50 SD = 8.41 vs. 56.13 SD = 6.31, p< .05), social problems (mean T 64.71 SD = 8.95 vs. 58.79 SD = 9.41, p < .05), thoughts problems (mean T 67.71 SD = 9.71 vs. 58.04 SD = 7.17, p < .05) and were more withdrawn/depressed (mean T 64.04 SD = 9.11 vs. 55.46 SD = 6.48, p < .05). Borderline difficulties were detected for the affective, somatic and ADHD CBCL DSM orientated subscales in PWS group with PWS children having significantly more somatic (mean T 63.05 SD = 8.33 vs. 52.00 SD = 6.48, P < .05) and affective (mean T 66.22 SD = 8.51, vs. 60.08 SD = 6.829 P < .05) problems than controls. The analysis of BSI scales revealed that parents of PSW children in comparison to controls had more somatization, phobic anxiety, obsessive compulsion, and anxiety problems.

PWS represents a complex psychological disorder with multiple areas of disturbances.