Global rates of autism have been increasing, and although we have identified several genes and environmental factors with development of the disease, the ultimate cause is yet to be determined. One might argue that this global increase in autism rates is due to increased diagnosis and classification of the disease. While this could be true, it is not the whole story.
There have been many different genes associated with autism. Most of these genes are caused by certain mutations that occur within the genome. While parents may not carry the mutation themselves, it is possible for the mutations to occur in their reproductive cells or to the baby during pregnancy. Many different environmental factors have been connected with increased risk of gene mutations. As you can see in the figure below, mutations can be attributed to Mendelian Disorders, rare de novo mutations, and chromosome abnormalities.
The question that is trying to be answered now is what makes up the remaining 77% of genetic mutations? Studies have shown connections between environmental factors during pregnancy and early development and rates of autism. These environmental factors include:
Prenatal Viral Infection: Maternal infection and complication of immune system health during pregnancy has been integrally linked with development of autism.
Zinc Deficiency: Zinc deficiencies have been observed in autistic children. This deficiency could play a large role in gene expression.
Abnormal Melatonin Synthesis: Inability to produce sufficient melatonin has been observed at high rates in autistic patients. This abnormal melatonin synthesis leads to complications in the circadian rhythm, leading to abnormal sleep patterns.
Maternal Diabetes: Maternal diabetes during pregnancy has lead to a twofold increased risk of the child developing autism.
Prenatal and Perinatal Stress: High levels of stress have been associated with increased risk of autism.
Toxins: Many toxins have also been associated with gene dysfunction and the development of autism.
Parental Age: The age of both mother and father have a profound influence on the development of autism. The older the parents are, the more likely complications will occur in pregnancy, leading to autism.
Postnatal Risk factors: Gastrointestinal abnormalities, allergies, exposure to drugs, infection, and heavy metals have also been associated with development of autism after birth.
Many different causes have been proposed, and currently there is no one cause that stands out as the one and only cause to the disorder. Further research must be done to better understand autism and how it can be prevented. However one thing is certain. Vaccination has been discounted as a source of autism. So parents, DON’T HESITATE, VACCINATE!!
A Disorder of Growing Uncertainty: Autism
