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Autism Genes: Expert Q&A

  • Posted 07.13.09
  • NOVA scienceNOW

On July 13, 2009, Charles Nelson answered selected questions about the diagnosis, treatment, research, and other aspects of autism.

Charles Nelson

Charles Nelson

Charles Nelson is Research Director of the Developmental Medicine Center and Richard David Scott Chair in Pediatric Developmental Medicine Research at Children's Hospital Boston. Full Bio

Photo credit: Charles Nelson

Charles Nelson is Research Director of the Developmental Medicine Center and Richard David Scott Chair in Pediatric Developmental Medicine Research at Children's Hospital Boston. He is also a Professor of Pediatrics and Neuroscience at Harvard Medical School. Nelson's research interests are broadly concerned with developmental cognitive neuroscience. His specific interests focus on the effects of early experience on brain and behavioral development, particularly as such experience influences the development of both memory and the ability to recognize faces. Nelson studies typically developing children, children at risk for neurodevelopmental disorders (particularly those at risk for developing autism or memory impairments), and children experiencing profound early psychosocial deprivation. In his lab, he employs a variety of neuroimaging and behavioral tools, including EEG, MRI, fNIRS (functional Near-Infrared Spectroscopy), and eye-tracking. Nelson received an honors degree in psychology from McGill University, masters degrees in educational psychology and psychology from the University of Wisconsin, and a Ph.D. in developmental and child psychology from the University of Kansas. His hobbies include squash, reading, and cooking.

Q: What factors do doctors look for in diagnosing autism? My brother has shown many a symptom but has had no professional help (other than counseling). We have always assumed autism, but there are some seemingly unrelated quirks in how his mind works (how he sees and interprets objects), and though he has been withdrawn from the world, he still is very emotionally sensitive and cannot stand the people (or animals) around him feeling hurt. Thank you. Campbell Forrester, Dana Point, California

Charles Nelson: The classic criteria one looks for in young children are restricted or repetitive motor behavior and qualitative impairment in social relatedness/communication (including delays or impairments in language). That said, we think of autism as a spectrum of disorders, and children can "sit" virtually anywhere on this spectrum. Thus, same may be profoundly retarded, have no language, and have an intractable seizure disorder, whereas others may have an exceptionally high IQ and are only mildly impaired in the social sphere. From what you say in your note, it may well be worthwhile having your brother formally evaluated by a child psychologist, pediatrician, or psychiatrist who specializes in autism, if for no other reason than to figure out what is going on and how you might help your brother.

Q: Hello, Dr. Nelson. My younger brother is 14 years old and has autism. My family has been considering trying hyperbaric oxygen treatment, since there have been so many stories of autistic children benefiting from hyperbaric oxygen chambers. Do you think autistic people can benefit from this treatment, or is the investment a waste of time and money? Thank you. Farah Weheba, Wichita, Kansas

Nelson: To my knowledge there is no credible scientific evidence supporting the use of this treatment in autism.

Q: Dr. Nelson, I understand that the medical community is now predominantly in agreement that autism is a neurological disorder with behavioral manifestations. As such, why does it continue to be diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders (DSM)? When does the medical community plan to assign autism its rightful "medical" diagnosis and treat it as a "medical" condition, as opposed to a "mental disorder"? By incorrectly placing autism under the umbrella of "mental health disorders," insurance companies can, and summarily do, avoid coverage of the appropriate medical treatments for autism spectrum disorders. Thank you for your reply. Sincerely, Michelle Garcia Melind, Elmhurst, Illinois

Nelson: The line between medical vs. psychological is thin. The American Psychiatric Association is in the process of revising its Diagnostic and Statistical Manual (DSM), which should be complete in 2010. The committee is hard at work trying to address the very issues you raise in your note. We'll see what comes of their deliberations in a year or so.

Q: Dear Prof. Nelson, were autism patients in the early 1900's simply undiagnosed, or has there been a significant increase in the number of autism patients which may signify an environmental cause? Thomas Hartl, Canton, Michigan

Nelson: Autism is no different than other disorders: The way we view them evolves over time. There has always been autism, as there has always been other disorders, but 100 years ago they were not recognized as such. One wonders what our view of autism will be 100 years from now.

Now, the latter part of your question—is there an environmental "cause"—is more difficult to address. Many experts suspect that in some children the environment can be a trigger for the disorder, but as yet, there is nothing definitive known about what aspects of the environment might contribute to the disorder.

Q: Any ideas about why autistic people are often savant as well? Anonymous

Nelson: This remains a mystery.

Q: My son Rik, 9 years old, is diagnosed with PDD-NOS. [Editor's note: Pervasive Developmental Disorder-Not Otherwise Specified is a diagnosis on the autistic spectrum.] He feels thirsty all the time. How will it minimize? Premnath, Durgapur, West Bengal, India

Nelson: I'm not qualified to address this (although my intuition is that this child's thirst has nothing to do with autism).

Q: What is your position/opinion about vaccines and autism? Gillian Ireland, Saint Albans, Vermont

Q: So much emphasis has been placed on the role of mercury in childhood vaccines as a primary cause of autism. Is there any truth to this, and are we focusing so much on mercury that we may be overlooking other possible factors? Kim Hill, Asheville, North Carolina

Q: Please explain the scientific response to people that believe they should not vaccinate their children because they think it causes autism. Mike Jones, Lee's Summit, Missouri

Nelson: A response to all three questions: At the present time, there is no credible scientific evidence linking vaccines (or the mercury in vaccines) to autism. A doctor in the United Kingdom, Andrew Wakefield, was the first to draw attention to the possible role of vaccines, but since that time, study after study, all over the world, has failed to find a credible, reliable link. Moreover, the risk of not vaccinating a child is great, both to that child and to the community.

Q: Over recent years, it appears that the incidence of autism has been on the rise. If this true, what are the factors related to this increase? Anonymous

Nelson: This is an excellent question, one that is receiving a great deal of attention. One contributing factor is that we have better diagnostic tools and can also diagnose at an earlier age. But over and above these two observations, there does appear to be an increase in prevalence that science cannot currently explain.

Q: What are the factors that cause an autism gene to express itself in some children and not in others? Eileen Albert, New York, New York

Q: Is there is a gene or chromosome that causes autism? Why is there such a wide variety of severities on the spectrum, and would it depend on where the mystery gene is at on the chromosome that causes the more severe cases of autism? Donna Jobgen, Dubuque, Iowa

Nelson: Tremendous progress is being made in understanding the genetic contributions to autism. By some estimates 10-15% of all cases of autism can be explained by genetics. However, it is important to note that a) there is no single gene responsible for autism, b) there may be different combinations of genes and thus the genes responsible for autism in one child may differ from that of another child, and finally, c) some of the genetic causes are not inherited but are "de novo," meaning they arise spontaneously in the germ line. An example of this is the 16P mutation (copy number variant) that has received much attention of late.

Q: I have a four-year-old boy on the spectrum. I was wondering why autistic children have such a hard time sleeping. We have struggled with his sleeping habits for about 20 months. He rarely sleeps thru the night. He will wake 2:00, 3:00 a.m., stay up, and go back down 6:00, 7:00 a.m. There are times he will go down 9:00 and sleep only till 4:30-5:00 a.m. There has been no rhyme or reason to any of this. I know this is common among these children, but why? Thank you. Pat, Woodridge, Illinois

Nelson: I'm afraid I'm not qualified to address this (although there are a number of reports that substantiate your view of your child).

Q: I have two grandchildren—one, 12, who has Aspergers and one girl who is 11 who has severe autism. Is there anywhere we can get help? My daughter is poverty level and cannot get help because of her finances and because of where we live—most places are in Chicago. Theresa, Peoria, Illinois

Q: Doctor, a dear friend of mine has a nine-year-old boy that's autistic, and she has a limited financial budget. How best could she invest her monies to improve her son's quality of life? Regards, Philippe Lapointe, Ottawa, Ontario, Canada

Nelson: Sorry, I'm over my head on the general question of what a family without financial resources can do. But re: referral for the family in Chicago, there are some very good people based in the Department of Psychiatry at the University of Illinois-Chicago.

Q: My son is 12 and was diagnosed at 2.5 years old as high-functioning autistic. He will only eat pizza, chicken nuggets, or hambugers for meals and will eat cereal with milk. Why do autistic children seem to eat only specific foods? He has only brought pizza to school for lunch since he started at age 3, and he is going into the 7th grade. Anonymous

Nelson: Such food "preferences" are not specific to children with autism; typically developing children will exhibit the same behavior. Case in point: some three-year-olds who will only eat white things or beige things.

Q: Dear Sir, My son was diagnosed with autism about 13 years ago when he was nine.

After years of swimming upstream in the sea of treatments, educational approaches, and general governmental neglect, I am dogged by a question: Is autism really a condition that needs a cure? That is, other than the crushing demands of society for conformity, is there any reason for Stephen to be labeled with a condition (and its implied cure)? He is not a danger to anyone—has he not the right to be a little odd, socially awkward, or uninterested in "normal" things? After years of dragging him from doctor to doctor, I am wondering if society shouldn't just let him be. So what if he lacks "practical" speech, if typical personal hygiene rules escape him, or if he lacks the intensity to drive a car or work in a stressful, fast-paced workplace? Do we need to cure him—or to cure society? Both are intractable to me. Anonymous

Nelson: I am sympathetic to your point of view, but, unfortunately, not all children with autism are as high-functioning as your son. Some autistic children have IQs well below 50, are self-injurious, have intractable seizures, and will never be able to care for themselves. In order to get such children services, it is imperative that they be accurately diagnosed.

Q: I was wondering if rates of autism are going up in other countries as they seem to be here in the U.S.? Anonymous

Nelson: They are, although the rates still vary country by country, e.g., in countries with sophisticated diagnostics, the prevalence is likely higher than it is in countries where the ability to diagnose is less sophisticated.

Q: Is there any relationship in the chemistry of the brain between autistic individuals and those with ADD or similar behaviors? Anonymous

Nelson: Good question. There does appear to be considerable co-morbidity between autism and other disorders. ADD is one such disorder and anxiety is another. We're still not sure what to make of this, and indeed, it is sometimes a challenge to know which is the primary disorder and which the secondary one. This is where a skilled, experienced clinician comes in.

Q: Has new information from brain-imagery studies impacted education programs for autistic children? Mary Blackwell, Austin, Texas

Nelson: We're not there yet; the work on neuroimaging is still very much in the discovery mode, and we're not ready to generalize the findings to education programs just yet.

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