Genetics of autism: overview and new directions.
Autism is partly genetic, but the exact genes remain elusive after decades of looking.
01Research in Context
What this study did
Leung et al. (1998) wrote a big-picture review. They asked, "What do we know about autism genes so far?"
They read family, twin, and early gene studies. They did not run new lab work.
What they found
Every study agreed: autism runs in families. No single gene explained most cases.
The authors said, "We need cleaner methods before we can find the real genes."
How this fits with other research
Swenson (2008) later showed the 1998 wish list was too small. That paper said teams now need thousands of families, not hundreds, and must check common and rare variants at the same time.
Rutter (2013) went further. After fifteen years of gene hunts, he argued the field should stop treating autism as one thing. The 1998 "find the genes" goal had morphed into "rethink the whole disorder."
Mattingly et al. (2025) extends the story into the lab. They describe growing tiny human neurons from stem cells. These dishes let scientists test 1998-era suspect genes in living brain tissue.
Why it matters
For you as a clinician, the takeaway is stability. Every update since 1998 keeps the same bottom line: genes matter, but they are only part of the picture. When you explain autism to families, you can say science is sure about heritability yet still searching for specifics. No need to wait for gene tests to start good ABA.
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02At a glance
03Original abstract
Genetic epidemiology is the study of inherited factors involved in the etiology of a disease or disorder and uses the methods of both medical genetics and clinical epidemiology. In general, genetic epidemiology tries to answer the following four questions: Is the disorder inherited; What phenotype is inherited; How is it inherited or what is the mode of transmission; and What is the nature of the genetic mutation, if any, that gives rise to the disorder? The hope is that by identifying the gene or genes involved in pathophysiology, a much better understanding of the steps from gene product to phenotype will be possible, leading to improvements in diagnosis, an opportunity for thoughtful family planning, and perhaps, most important, to the development of treatments based on an understanding of the biochemistry of the disorder. We review the current knowledge of the genetic epidemiology of autism and the other pervasive developmental disorders (PDDs) and highlight promising new directions. There seems to be widespread agreement that the PDDs are caused, at least in part, by genetic factors. There is also some agreement on the phenotypic boundaries associated with these same genetic factors. However, many points of uncertainty remain, and several methodologic issues need to be resolved before further progress in mapping susceptibility genes is possible. We do not specifically review molecular studies, medical conditions associated with autism, or the broader autism phenotype, as these topics are covered in other papers in this special issue.
Journal of autism and developmental disorders, 1998 · doi:10.1023/a:1026096203946