If 1 out of every 150 births in the US is a child with autism isn't it most likely that the illness is environmental instead of genetic?

Answer 1

The current understanding is that approximately 65% of people have an underlying genetic risk for autism (potential to have autistic children), but that changing factors in today's society and/or environment are sending autism rates skyrocketing.

Approximately 1 in 150 children have autism, that is approx. 73 a day, and approx. 26,767 children a year are born with autism in the US.

These numbers are up from 1 in 10,000 a generation ago, and 3-4 generations ago, autism was practically unknown.

Likely reasons for the increase include:

- Increased numbers of pregnant women on medication during pregnancy. For example, the anticonvulsant drug sodium valproate (epilim/depakote) is proven in studies to cause a 10% risk of autism when unborn babies are exposed to it.

- Various other anticonvulsant drugs and hormonal drugs are also suspect, and under investigation for causing increased risk of autism.

- Increased diagnosis. More children at the "softer" end of the spectrum are now obtaining diagnosis. Children that a decade ago would simply have been considered "quirky" are now being diagnosed with high functioning autism.

That said, autism is now appearing commonly in families with no known history of the disorder, and no genetic abnomalities.

Even taking increased diagnosis into consideration, autism rates are increasing rapidly enough for it to be of high concern to all communities and prospective parents.

- Environmental genetic damage. It is generally accepted that certain chemicals in our environment cause genetic damage. This may be associated with the increase in autism rates. Various plastics are known to leach hormone disrupting chemicals into our water and food supplies, and autism is suspected in some scientific quarters to be caused by hormone disruption.

- Older parental ages. Women are having children when older. Genetic damage is more likely to occur in eggs from older women, and in sperm cells from older men.

Unknown but possible other candidates for autism rate increase include:

- foetal ultrasound, which has never been tested for human safety yet is now universal

- vaccine overload, where too many vaccines create an immune response overload in young children / babies

- general environmental pollution, including lead and Mercury, plus a host of other damaging chemicals and poisons.

- genetic risk only, with no environmental factors involved. This is extremely unlikely, due to the rapidly increasing numbers of autism diagnoses worldwide.