Role of Parental Occupation in Autism Spectrum Disorder Diagnosis and Severity

Background:  Although the specific genotypic aspects of autism spectrum disorder (ASD) have yet to be identified, some investigators have suggested that parents of children with ASD may present with less recognizable autistic-like phenotypic characteristics. Others have suggested that many professionals with highly systemizing occupations are functioning with undiagnosed Asperger’s Disorders. However, results from studies on ASD diagnosis and technical occupations of parents have been conflicting.

Objectives:  To (1) test associations between reported parental occupations and ASD diagnosis and (2) test the association of parental occupational characteristics on ASD severity in a subsample containing only children with an ASD diagnosis.

Methods:  This is a secondary exploratory analysis of data from two previous studies conducted in a sample of 273 children ages 7 to 18 years. The first study was a case-control study of developmental impairment of the orbitofrontal-limbic circuit as a possible biomarker for ASD. The second study was a project designed to assess the behavioral and cognitive aspects of attention deficit hyperactivity disorder (ADHD) in children with ASD. Children for both studies were recruited from the same educational, clinical, and community sources. Suspected ASD cases were determined by clinical interview and observation.  Those meeting DSM-IV-TR criteria were administered both the Autism Diagnostic Interview, Revised (ADI-R) and Autism Diagnostic Observation Schedule (ADOS) to confirm diagnosis. Parental occupations were established through demographic questionnaires during assessment. We used the Standard Occupational Classification (SOC) system to classify occupational characteristics of interest and National Institute of Occupational Safety and Health (NIOSH) reports to determine risk of occupational exposures. We performed logistic regression to explore associations of ASD status with certain white-collar occupations and occupational characteristics and Generalized Linear Models (GLM) to investigate differences in mean ADOS and ADI-R domain and total scores for parental occupation characteristics.

Results:  Demographic characteristics of cases and controls were similar. Fathers of cases were six times more likely to work in healthcare (AOR=6.38, P<0.01) and four times more likely to work in finance (AOR=4.60, P=0.03) after adjustment for demographic variables.  In subanalysis, the mean communication score (P<0.01) and social impairment score (P=0.04) were higher for children with both parents having technical occupations. Furthermore, in multivariate analysis, mean ADI-R total scores were higher for children of fathers with technical occupations (P=0.02).  Significance was also seen with higher ADI-R scores for children with both parents having technical occupations (P=0.03).

Conclusions:  Our findings suggest that there is a joint association between parental occupation and ASD severity, as well as a relationship between paternal occupation and ASD diagnosis. These results are supportive of a “broader phenotype” in parents of children with ASD and assortative mating in adults with these autistic-like characteristics. This effect could be due to genetic or epigenetic predisposition which might contribute to having offspring with greater ASD severity. Therefore, more analysis should be done to determine what factors contribute to occupation choices, and how these factors, if identifiable, can add to the risk of communication or social impairment in the offspring of these individuals.