'X' Marks The Spot In Hunt For Autism Genes

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'X' Marks The Spot In Hunt For Autism Genes

http://tinyurl.com/hn7by

A previously unrecognised trigger for autism may have been found, in

the form of mutations that affects neuron development in a brain

region important for learning and social interaction.

Autism is around four times more common in boys than girls, which

suggests that mutations on the X chromosome play a role, as boys lack

a second X chromosome that could compensate for any genetic

abnormality. Studies have identified several hundred gene candidates,

but no conclusive links to a specific mutation.

Now a 15-year-long international screening effort has identified two

different mutations of the same X chromosome gene, which seem to be

linked to autism in two unrelated families (Molecular Psychiatry, DOI:

10.1038/sj.mp.4001883). The gene encodes a protein called L10, a vital

component of ribosomes - the structures that build proteins. L10 is

most actively manufactured in the hippocampus, a brain region

important in learning and memory as well as some social and emotional

functions.

Lead author Sabine Klauck of the Division of Molecular Genome Analysis

at the German Cancer Research Centre in Heidelberg says the mutations

are rare, and not present in their other patients. But they do reveal

an important pathway by which different genetic defects could lead to

different types of autism.

Essi Viding of University College London says the findings are in line

with structural brain changes seen in autism, but cautions that many

other genes will be involved.

From issue 2568 of New Scientist magazine, 08 September 2006, page 20