Influence of Molecular Genetic Classes on Behavior in Prader-Willi Syndrome

A wide range of behavioral phenotypes has been described in PWS patients including autism spectrum disorder (ASD). The prevalence of behavioral disorders was studied in 292 participants over 3 years with genetically confirmed PWS (N = 164 females and N = 128 males) with deletion (N = 182) and mUPD (maternal uniparental disomy) (N = 99). The prevalence of ASD, and other behavioral disorders was tested for association with gender, genetic subtypes, and growth hormone (GH) treatment. The prevalence of ASD in PWS individuals was 19.5%, in concordance with previous studies at 25%. The frequency of ADHD was 10.7%. The mean age at diagnosis for ASD, ADHD, and disruptive behavior was 14.9 ± 10.5, 9.3 ± 5.9, and 19.6 ± 14 years, respectively. There was no statistically significant difference in the prevalence of ASD and ADHD between deletion and UPD subjects, and between GH-treated and non-treated subjects. Patients with mUPD had higher frequencies of anxiety than those with deletions (p = 0.001). GH-treated participants had a lower frequency of depression and a higher frequency of anxiety than non-treated participants (p = 0.04, p = 0.02, respectively). This is the largest study to evaluate an association between genetically confirmed PWS and ASD. We found no significant differences in the frequency of ASD and other behavioral disorders across the genetic groups and GH treatment.