Myth of the Genetic Origin of Autism 67
Myth 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