Autism Spectrum Disorder (ASD) is a condition impacting individuals lifelong and results in needs across a variety of domains. Genetic factors contribute significantly to the development of ASD. The diagnostic yield of clinical genetic testing in children with ASD is as high as 17-21%. Genetic test abnormalities can influence medical treatment and health screening for ASD individuals, while also influencing family planning for these individuals and their siblings. Despite the benefits as well as the impact of ASD on society, no study has been conducted of genetic abnormalities in ASD adults.
In our experience, the majority of ASD adults have either never had genetic testing or the testing was done long ago and did not benefit from the increased yield of modern genetic testing utilizing comparative genomic hybridization (CGH) techniques. Therefore, the prevalence of genetic abnormalities in adults with ASD is unknown.
Recently, a study of adults with intellectual disability (ID) revealed a prevalence of genetic abnormalities higher than predicted by pediatric studies of ID. It is hypothesized that this higher yield reflects a tendency to test adults with more severe ID, thus increasing the percentage of individuals with abnormalities.
Objectives:
The primary objective is to determine the prevalence of clinical genetic test abnormalities in ASD adults.
A secondary objective is to describe characteristics of the genetic abnormalities as well as physical and demographic features of individuals with these genetic abnormalities as compared to those without genetic abnormalities.
Methods:
All ASD adults age 18 and over seen in the UW Adult Genetics Clinic between July 1, 2009, and March 30, 2012, will be offered to participate. Currently, this includes approximately 35 subjects with an estimated 40-50 subjects total at the time of final analysis. Both retrospective and prospective chart analysis will be conducted depending on the time the patient was seen in the clinic. Data abstracted will include age, sex, ASD diagnostic subtype, genetic test results, imaging results, EEG results, neuropsychological test results, physical exam features, medical history, medications, family history, developmental history, and social demographics such as level of education, employment status, and living situation. Clinical and demographic features will be compared between individuals with genetic abnormalities versus those without.
Results:
We hypothesize a greater prevalence in detecting genetic abnormalities as compared to similar studies in ASD children, as we would predict testing of adults focuses on a more severely impacted subgroup. We also hypothesize a greater prevalence of genetic abnormalities in ASD individuals with abnormal physical exam features and more severe functional deficits.
Conclusions:
The importance of this study is in providing information to help guide clinicians in decision-making regarding genetic testing for adults with ASD. The large sample size will allow clinicians to better understand expected test results in adults with ASD and the clinical and demographic features associated with these genetic test abnormalities.