The exact cause of autism is not well known till date. But researchers have found through observations various factors that may cause or lead to autism. Autism is a lifelong disorder which can be caused in such situations -
- During Pregnancy- Exposure to drugs, chemicals and illness during pregnancy may increase chances of autism or cause Autism Spectrum Disorder (ASD) in a child. It is also seen that premature births, toxic exposure during pregnancy, alcohol consumption and other chemical exposures during the developmental period of a child (that is when a child is in the womb) may lead to autism and other neurological developmental disorders like fragile X syndrome, epilepsy etc.
- Genetic Factors like prior history of autism in a family increases the chances of ASD in a new born child as it may be genetically inherited by the baby. Siblings of a child with autism are more likely to be affected with the disease.
- Environmental Factors may also cause autism. Various factors such as viral infections, metabolic imbalance and exposure to toxins may be the reason.
- Severe infections of brain like encephalitis, meningitis, etc. may also lead to ASD in some people.
Autism may be caused by a combination of genetic and environmental factors in some cases. Environmental factors may affect normal gene functioning and may cause neuro-degenerative conditions which may lead to disorders.
Besides these factors, people also associate bad parenting as a cause of autism. However, there has been no scientific evidence to support this claim.
There is also a misconception that some vaccines cause autism in children but studies found that these vaccines do not at all cause autism in children. People earlier thought and believed that thiomersal which is used as a preservative in some vaccines and contains mercury is a cause of autism. There are other misconceptions too about autism and its causes like –bad parenting and eating gluten rich diet may lead to autism, but evidence do not prove these assumptions.
Health Conditions - There are certain health conditions which, if prolonged, may affect an individual and lead to autism. These conditions are-
- Genetic Conditions - Some of the rare genetic conditions like fragile X syndrome, rett syndrome, and tuberous sclerosis may cause autism or symptoms like autism.
- Growth of tumour around nerve cells called as ‘neurofibromatosis’ may cause autism.
- Epilepsy during early childhood usually before 1 year of age is considered to cause autism. This epileptic condition is known as “infantile spasms.”
- Muscular dystrophy (which represents a group of genetically inherited conditions which gradually lead to muscle weakening), cerebral palsy (a condition that affects nervous system and brain and causes problems in movement and coordination) and Down’s syndrome (learning disability and various physical features caused by this condition) are some other conditions that are considered by researchers to cause autism or similar conditions.