DE NOVO POINT MUTATIONS IN SUCH GENES COULD EXPLAIN THE ADVANCED PATERNAL AGE ASSOCIATION THAT HAS BEEN REPORTED IN AUTISM

Arthur L. Beaudet, M.D.



The two studies1, 2 greatly strengthen the growing awareness that a substantial fraction of autism is caused by genomic rearrangements. Particularly in the case of deletions, loss-of-function point mutations in genes in these regions are likely to be important as well. Most of these are de novo mutations not present in the parents. The children with identifiable genetic abnormalities are often in the syndromic group, and the sex ratio for these individuals tends to be 1:1, except for X-linked disorders6, 7.

De novo point mutations in such genes could explain the advanced paternal age association that has been reported for autism13. There is no evidence, however, that the risk of a de novo CNV is related to the age of either parent.

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Point Mutation
A point mutation is a simple change in one base of the gene sequence. This is equivalent to changing one letter in a sentence, such as this example, where we change the 'c' in cat to an 'h':


Original
The fat cat ate the wee rat.

Point Mutation The fat hat ate the wee rat.