Association between Prader Willi Syndrome and Autism Spectrum Disorder: A Survey Study

Background:

Prader-Willi Syndrome (PWS) is a rare genetic disorder that results from a lack of expression of paternally derived genes on chromosome 15q11-13. There has been a growing recognition of the potential relationship between PWS and Autism Spectrum Disorders (ASD), but risk factors are unknown.

Objectives:

This study aims to investigate the association between PWS and ASD and explore their genotypic/phenotypic correlations via a large sample survey.

Methods:

Genetically-diagnosed PWS patients were separated into three groups according to their ages and handed out differently survey respectively to examine their probability of having ASD: (1) 0- 36 months: Ages & Stages Questionnaires, Third Edition (ASQ-3); (2) 18-36 months: Modified Checklist for Autism in Toddlers (M-CHAT); (3) over 36 months: Gilliam Autism Rating Scale: 3rd Edition (GARS-3). Survey was handed out to 465 subjects, and 328 results were retrieved, 276 of which were valid.

Results:

Both ASQ-3 and GARS-3 are used to determined Autism Level Index. The results of GARS-3 are autism level index by nature. As for ASQ-3 group, we classified the subject’s autism level index by their total ASQ-3 scores: 0~53: level 3; 54~106: level 2; 107~159: level 1; 160~300: level 0. There are 37/123 (30.08%) participants with score level 3 in ASQ-3 group and 23/131 (17.56%) in GARS-3 group. The independent variables we considered include age, sex, weight, height, PWS genotypes, usage of growth hormones, comorbidity condition epilepsy, and mode of delivery. Linear regression was performed to examine the relationship between these factors and autism level index. In the univariate analysis, genotype is significantly associated with ASD score (p value of 0.04) in ASQ-3 group.

Conclusions:

This survey provides preliminary but valuable data to explore the relationship between PWS and ASD, we expect to identify some predictors for PWS patients who has co-morbid ASD and the severity and incidence of other complications.