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Autism News

I have been greatly remiss in reporting on developments in the world of autism research. To ameliorate that deficiency, here is a triple helping.

First, we have good news in the area of genetic research into the roots of autism. The Genome News Network reports:

Researchers studying families with autism have pinpointed a gene that may increase susceptibility to autism in a broad population. Most rare genetic mutations associated with autism have been identified in single families.

Joseph D. Buxbaum and colleagues at Mount Sinai School of Medicine in New York conducted genetic screening of 411 families with members who have autism. The sample included 2,000 people, of whom 720 are afflicted with the disorder.

The researchers report their findings in this month’s American Journal of Psychiatry…

Previous research had demonstrated an association between a gene located on chromosome 2 and autism. This chromosome is known to be associated with deficits in language development—a hallmark of autism. This time, researchers looked for a gene on a specific part of the chromosome, zeroing in on the gene known as SLC25A12.

Buxbaum and his colleagues confirmed that the gene occurs with greater frequency in autistic individuals and in members of their family than in families without the disorder.

The gene increases risk for the disease but carrying the gene doesn’t necessarily mean that an individual will develop the disease, Buxbaum says, noting that more than one gene is involved in autism. But individuals with the gene have twice the risk for developing the disorder as individuals without it.

The identification of gene SLC25A12 as being associated with autism makes the identification of other genes far easier. The creation of a genetic profile of persons at increased risk of autism may, in the middle term, permit a blood test to identify candidates for early intervention. Early intervention with intensive social science therapies (ABA etc.) is the current state of the art for achieving better outcomes for autistics.

In the long term, identification of the genetic roots of autism could lead to a cure. Good news indeed.

Last year a popular news magazine ran a story on autism suggesting that autism is an “extreme version of normal male intelligence.” I have my doubts about such a theory but, since God failed to grant me a monopoly on wisdom (for inexplicable reasons know only to Her), each must make his or her own determination.

The leading proponent of the “extreme maleness” theory is Cambridge University psychologist Simon Baron-Cohen. His book, The Essential Difference: The Truth About the Male and Female Brain is available here. Actually, if you want to buy it, may I suggest that you do so through Jim’s portal?

Simon Baron-Cohen has a new research report supporting his theory. A Sunday Herald story reports:

A leading specialist has claimed autism may be linked to over-production of the male hormone testosterone.

Research by Professor Simon Baron-Cohen has shown that babies who produce high levels of the hormone in the womb are more likely to develop abnormalities in social development and other autistic traits.

Baron-Cohen, director of the Autism Research Centre at Cambridge University, said his team had taken samples of amniotic fluid from the wombs of 3000 pregnant mothers to analyse for levels of testosterone.

On each baby’s first birthday, researchers videoed the child to determine social interaction with their mother, including how much eye contact they made. The research, the first of its kind to assess whether a foetus’s hormone levels could determine autism, found that babies who had produced higher levels of the male hormone were less likely to make eye contact with their parent.

Now, preliminary findings from Baron-Cohen’s latest research – which studies how the children cope socially at school – has again found that those with the highest levels of prenatal testosterone now face a greater challenge in forming friendships.

He said: “We have followed these women from before birth and we’ve looked at hormones, in particular pre natal testosterone. We are trying to establish whether hormone levels can influence social relationships. That is exactly what we have been finding.

“The children are now four and so we wanted to study them when they were just starting school, which is another social challenge. We have found that prenatal testosterone predicts how easily a child can make friends in a social group. These are brand new results.”

The initial results, which will be published later this year in the Journal of Child Psychology and Psychiatry, comes from a sample of 170 children. Baron-Cohen said that by the end of the year, researchers will have results for the thousands of children in the study.

He added: “None of these children has a diagnosis of autism but it is inevitable that a number will in a group of this size. Most will not get a diagnosis until they are around five or six.

“At the moment we are writing to all the women to find out which, if any, [of the babies] have a diagnosis of autism or a related child development condition. By the end of the year we may be able to test whether a child who had elevated levels of testosterone prenatally will go on to develop autism.”

I will await the further report on the research to make any judgments as to what, if anything, the research shows.

Another researcher thinks that autism is linked to a lack of Vitamin A. The news story is here:

Virtually every fortified cereal packet broadcasts the message that vitamin A is vital for good eyesight. But even the most gung-ho marketing manager would pause before claiming that the vitamin can dramatically improve the symptoms of autistic children by repairing damage to their retina. However, this is precisely the claim being made by an American paediatrician, who has evidence that treating these children with the right sort of vitamin A is not only highly effective but provides valuable new insights into some of the most puzzling symptoms of this disorder.

"Once you understand the way autistic children 'see' their world," says Dr Mary Megson, a professor of paediatrics at the Medical College of Virginia, "the fact that they don't look you in the eye and can't bear for things to be changed makes perfect sense." She emphatically rejects the widely accepted hypothesis that these children have no theory of mind (ie, no understanding that other people have their own thoughts, plans, points of view), and that they relate to other people as just another type of thing.

Instead, she maintains that their seemingly alienated behaviour is perfectly rational. It is their way of surviving in an extraordinary and terrifying visual world, the result of damage to a protein pathway that affects the way that certain specialised cells in their retinas work. "Imagine that everything appeared to you like a some paintings by Picasso, flat and two-dimensional, with various features superimposed," urges Dr Megson, who has specialised in developmental disorders for the last 15 years. "Or think of a Hockney collage, digitally remastered with all the depth cues taken out."

At a conference on nutritional psychiatry in London earlier this year, Dr Megson described how she has found that a proportion of her patients have only a tiny visual window on the world where things are reasonably clear and appear in 3D. All around this they only see colours and vague shapes. This makes it very hard for them to follow movement, especially the subtleties of facial expressions. Making sense of a new scene is equally challenging - hence their desperate insistence that everything should follow ritualised, predictable patterns...

She is certain that vaccination is at least one of the factors fuelling the rise. But although she agrees with Andrew Wakefield's controversial ideas about the effects of the MMR vaccine on the gut, she is particularly concerned about the vaccine for whooping cough and the "pertussis toxin" it contains. The evidence that she has seen has convinced her that certain children have a genetic susceptibility that makes certain proteins in their bodies vulnerable to damage by the toxin, which can have wide-ranging effects.

Known as "G proteins", they are found all over the body, but especially in the brain and guts, and are involved in boosting or dampening down the signals coming in from our senses (such as sight via the retina), as well as controlling such vital pathways as those for fats and glucose. The scary visual world of the children provides a close-up of how far-reaching the damage can be.

The theory is that receptors in the brain that control the "rod" cells in the retina have been affected by the whooping-cough vaccine. Rods are the cells that convey shading and depth, and allow us to see in black and white in the dark. They are more thickly clustered around the edge of the retina. "When these children look away from you," says Dr Megson, "they are turning their eyes so that the light reflected from your face lands on the outside of their retina, where the rods still have some function."

I am highly skeptical of that theory as well but, as noted above, each must make their own determination.

The common element in all three stories linked above is that autism research, long a red headed step-child, is now an extremely robust area of inquiry with many different researchers exploring many different theories. For those of us who would like to see the identification of the causes of autism in order to eventually find a cure, that is the really good news.

Posted by Dwight Meredith at April 26, 2004 02:50 PM | TrackBack