Wednesday 29 April 2009

The autistic gene

When my nephew was 9 years old he was obsessed with taps. Whenever he saw a tap, he had to turn it on. He has always been very good at drawing, he likes to draw even the smallest details you and I would miss. And if you want to know what day of the week March 23 is in 2050, just ask him and you will get the answer within seconds. He is a grown man now. He does not have many friends, he prefers being on his own. He has autism.

This week a study in Nature revealed evidence for a link between a specific gene and the development of autism.

Autism is a so-called neurodevelopmental disorder whereby the normal growth patterns of the central nervous system and the brain are altered. This abnormal development often results in learning disabilities, and social and emotional problems.

Over the years, there has been a lot of speculation as to what causes the brain and nervous system of autistic people to develop in a different way compared to the normal development. This has led to outrageous speculations about the lack of oxygen at birth, and to masses of people refusing to vaccinate their children with the MMR vaccine to protect them from getting measles, mumps and rubella, because of a falsely assumed link between autism and the vaccine for which no-one ever found any convincing evidence.

More controlled research has recently led to the discovery that the abnormal development seen in autism is especially affecting frontal regions of the brain. With the help of these regions we make plans and decisions and they do also support our interactions with other people. Another important discovery about the structure of the autistic brain is that there are a smaller number of pathways used for communication within the frontal lobes and between the frontal lobes and other regions in the brains of autistic people.

The article in Nature describes how in a group of 10.000 subjects consisting of autistic patients and their families, common genetic variants on 5p14.1 were identified. This gene has been tentatively linked with autism before, and this study confirms its importance in autism.

Thus, this study does not only show us the gene involved in autism, we can also derive from it that the class of genes to which this specific gene belongs is important for the normal development of structure and communication pathways in the healthy human brain.

Having a gene to hold accountable for autism does pose some ethical questions; with genetic screening it is possible to look at the genetic make-up of the unborn child and you could, based on the results, decide whether to proceed the pregnancy, or that, maybe, it's better for everybody not to have the child ... But given that the development of autism is not solely dependent on the genetic expression and there is a likely chance your child will be completely healthy, do you really want to make these decisions? And do we really want to rid the world of the Lewis Carrolls, Glenn Goulds, Beethovens, Vincent van Goghs and Wittgensteins, all of whom are suspected to have had autistic traits?