I join with John McMenemy in welcoming the news that the Scottish Government is investing £13.4 million in autism support and services, but must regrettably add a cautionary note (Letters, November 5).

Certain important facts appear to have escaped Government advisors on this issue. According to the Autism Research Unit at Cambridge University, autism in the UK has now reached the rate of one child in 64. In addition, a recent robust Californian Autism Twins Study has concluded that the condition can no longer be considered solely, or even for the most part, genetic.

In short, we have a massive increase in the numbers of children with autistic symptoms, (some commentators describing the increase as “epidemic”), and the cause of this unwelcome development cannot be ascribed to heritability factors.

Advice, information and support for autism sufferers is essential but if the Government wishes to truly address the problem of autism it must invest in the research that will identify the environmental factors responsible for its cause. To do otherwise condemns countless, as yet unborn children, and their families to the heartbreak, trauma and anguish which accompany the condition.

Bill Welsh,

President, Autism Treatment Trust,

ATT clinic,

29A Stafford Street,

Edinburgh.