Myth of the Genetic Origin of Autism 67Myth of the Genetic Origin of Autism
The first description of autistic psychopathy was by Asperger in 1938 and in
1943 Kanner published a paper describing 11 autistic children; neither sug-
gested that ASD was genetically inherited. Asperger identified in four boys a
pattern of behavior and abilities that included “a lack of empathy, little ability
to form friendships, one‐sided conversations, intense absorption in a special
interest, and clumsy movements.” What he described were high functioning
Autistic children (now called Asperger syndrome), two of whom went on to
become university professors and one won a Nobel Prize. As late as the mid‐
1970s there was little evidence of a genetic role in autism; now it is thought to
be one of the most heritable of all psychiatric conditions [21]. Before 1970, it
was considered that ASD was the result of bad mothering. Kanner’s descrip-
tion of autism led to decades of confused etiology and investigators believed
that a lack of maternal passion was involved leading to misconceptions of
autism as an infant’s response to “refrigerator mothers”. Starting in the late
1960s autism was established as a separate syndrome by demonstrating that it
is lifelong, distinguishing it from intellectual disability and schizophrenia and
from other developmental disorders [21,22].
Phenotypic Heterogeneity in Autism
ASD is characterized by broad heterogeneity in severity as well as in intellec-
tual and functional communication ability not only between individuals, but
also within the same individual over time [42]. In addition, a wide variety of
medical and psychiatric conditions are associated with ASD, including intesti-
nal disorders, epilepsy, and attention‐deficit/hyperactivity disorder (ADHD)
[43,44]. It is surmised that complex interactions between genetics, increasing
the risk for ASD, and environmental factors contribute to the broad heteroge-
neity observed in ASD [45]. This complexity makes determining the underly-
ing causes of and developing treatments for ASD very challenging [46].
Recently, a large, multicenter, multidisciplinary observational study, the EU‐
AIMS Longitudinal European Autism Project (LEAP), was undertaken to
examine biomarkers in ASD [47]. In the study, 437 children and adults with
ASD and 300 controls between 6 years and 30 years of age and with IQs rang-
ing from 50 to 148 were recruited from 6 research centers across 4 European
countries. Broad heterogeneity in presentation of ASD symptoms was observed
across the individuals in the study. Using a combination of clinical assessment
and interviews, the investigators found lower social symptoms, severity of
repetitive behavior, and inattentive and hyperactive/impulsive ADHD symp-
toms in adults. However, ASD symptom severity was higher in adults versus
adolescents in self‐reported assessments. Differences were also observed
between males and females. In diagnostic measures assessed through parent