Doctors finally may have answers about the cause of Autism
Of all the children’s health issues that have been explored by doctors, none has been more exhaustively researched than one particular question: Are vaccines linked to Autism? The answer has also come in. Doctors can now say with certainty that vaccines are not the cause of this developmental disorder. One of the most popular theories, that the measles-mumps-rubella vaccine may cause Autism, has been debunked by large-scale studies involving thousands of participants in several countries.
However, Autism still retains the fear factor owing to the uncertainty regarding its actual cause.
Even today, one in 50 children worldwide are affected by Autism. This rate has remained unchanged for about 30 years. It doesn’t help that doctors have long struggled to explain what exactly causes Autism. Many medical theories have been debunked and then replaced by new ones, but all of them are, afterall, theories.
The difficulty in reaching the root of Autism Spectrum syndrome may be blamed at the numerous symptoms it exhibits. In fact, Autism is a collection of close to 1000 different conditions. However, of all the causes of Autism, one thing that can be ascertained is that it’s a very genetic disorder.
Doctors have observed that a child with Autism has siblings in whom the symptoms of Autism is 10 times higher than in the general population. The same phenomenon has been observed in large sections of population.
Researchers first recognized the genetic nature of the disorder in the 1970s, with studies on twins involving at least one sibling with Autism. It was found that monozygotic (or identical) twins were more likely to have Autism in common than dizygotic (or non-identical) twins who shared less number of common traits.
Since then, large-scale population studies have uncovered the same pattern — and researchers have come to believe that shared genetic variants in families are probably more important than shared environments for triggering the disorder.
However, not everyone with those genetic mutations has Autism, and that’s because researchers believe it’s not mutations alone that cause the disorder. In many cases, the underlying genetic predisposition or mutation needs to collide with a range of potential environmental triggers.
Finding those environmental risk factors is where things get murky pretty quickly. Researchers have proposed dozens of potential environmental contributors of Autism, including air pollution, pesticides, antidepressants, and viruses. A few of them have concrete science behind them.
Overall, the evidence for prenatal exposures is stronger than the evidence for the range of postnatal causes that may trigger Autism. It’ll time take time for scientists to unlock the biology of Autism, and how genetics and the environment work together to determine a person’s Autism risk.