I don’t often venture into the fray whereby the misinformed continue to insist that thimerosal-containing vaccines cause autistic spectrum disorders when all evidence to date has led the scientific community to reject this hypothesis. However, recent stories on celebrities, namely Jenny McCarthy and Donald Trump, spouting forth about vaccines and autism led me to read with great interest a superb piece of science journalism by Ashley Pettus in the Jan-Feb 2008 issue of Harvard Magazine entitled, “A Spectrum of Disorders: The urgent search to understand the biological basis of autism.”
In this well-research, four-page article written for general audiences, Pettus gives the antivaxers the one paragraph that the topic deserves:
Many parents became convinced that the escalating numbers of cases stemmed from exposure to thimerosal, a mercury-based preservative used in childhood vaccines. Another theory linked the measles/mumps/rubella (MMR) vaccine, in particular, to the onset of autistic symptoms. Numerous epidemiological studies have failed to substantiate these claims, and in 2004 the Institute of Medicine of the National Academies found no causal relationship between either mercury or MMR vaccine and autism.
After a concise and informative history of autism and Asperger’s Disorder, Pettus instead spends the bulk of the article on the area where autism advocates should be registering their support: the genetic variation, usually spontaneous and not heritable, that underlying the spectrum of disorders.
A 1977 study of twins provided the first evidence of a genetic basis for autism. If one twin had the disorder, the other was far more likely to have it if he or she was identical rather than fraternal. (Because identical twins share their entire DNA, while fraternal twins share only half on average, a disease that tends to co-occur in identical pairs indicates genetic influence.) The discovery helped undermine the prevailing psychoanalytic theories that blamed autism on bad parenting and, in particular, on cold, unaffectionate, “refrigerator” mothers.
What has emerged from subsequent work is the autism and related disorders are complex, multigenic syndromes that require a multidisciplinary approach to solve:
“Autism is a problem that no one person or discipline can figure out alone,” explains James Gusella, Bullard professor of neurogenetics and director of the Center for Human Genetic Research at Massachusetts General Hospital (MGH). Gusella chairs the executive committee of the Boston Autism Consortium, a largely privately funded initiative that began in 2005 to take advantage of the wealth of expertise, technological resources, and patient databases concentrated in the area. The consortium brings together more than 50 researchers from Harvard, MIT, the Broad Institute, MGH, Children’s Hospital, Boston University, Beth Israel Deaconess Medical Center, and Tufts University to tackle different aspects of the disease cycle and to share results.
Understanding the true molecular and cellular basis of autism and early neuronal plasticity is already leading to some therapies, such as Applied Behavioral Analysis, that may help offset aberrant synaptic connections in spectrum disorders.
Note the key descriptor of the Boston Autism Consortium above: “a largely privately funded initiative.”
If The Donald truly cares about the investigation of the causes of autism, this is the kind of enterprise that deserves his support – one that is based on science, where the heavy hitters of psychiatry, neurology, population biology, and genetics are teaming up to tackle this complex medical issue.