Autism spectrum disorder (ASD) affects millions of people, impairing their communication and social skills while presenting a variety of behavioral issues.
Researchers have made consistent efforts to determine the causes of autism, but the sources of the disorder are highly complex.
Is there a genetic link to autism? And if not, or if the role of genetics is limited, what steps can you take to minimize your child’s likelihood of developing autism?
Autism: An Overview
Let’s start with a brief overview of ASD. ASD is a brain developmental disorder that interferes with a person’s ability to communicate, socialize, and behave around others. It’s known as a “spectrum” because people with autism have a wide range of symptoms which can range from mild (and barely noticeable) to severe (preventing them from living a normal life).
Autism usually begins to manifest in early childhood, showing symptoms within a child’s first year of life; however, some children develop normally for a time, only showing symptoms after 18 to 24 months of life.
Symptoms of autism vary significantly both in character and in severity. Children with autism usually demonstrate signs such as:
- Difficulty learning. Your child may have a hard time learning certain things.
- Difficulty with speech. They may struggle to form words or articulate certain concepts, or may only communicate nonverbally.
- Inability to understand tone, body language, or other communication subtleties. Tone, body language, and facial expressions are hard for people with ASD to recognize. They have a tendency to take communication literally.
- Inability to understand others’ feelings. People with ASD have trouble noticing and responding to the emotions of the people around them, resulting in difficulty forming social bonds.
- Repetitive movements. Some people with ASD make repetitive movements, like rocking back and forth.
- Highly focused interest. ASD can also cause people to become highly focused on specific things, like the spinning wheels of a toy car.
- Specific preferences. Children with ASD may have very specific preferences or requirements – such as only eating certain types of food.
The Causes of Autism
So what causes autism?
That’s a complicated question that scientists have been trying to answer for many years. It’s almost impossible to narrow down a single “cause” of autism right now and for several reasons.
Autism isn’t fully understood; it’s a difficult disorder to appropriately diagnose, which therefore makes it difficult to analyze. It also presents very differently in different individuals, showcasing different symptoms and severities that are orders of magnitude apart.
Here’s what we do know: genetics play at least some role in autism development, in at least some people. That’s a vague statement, and possibly an overly simple one, but scientists have not reached definitive conclusions here.
There are more than 1,000 genes that appear to be possibly associated with ASD, but many of these haven’t been confirmed. At present, genetic factors are thought to contribute 40 to 80 percent of the total risk for developing ASD.
In roughly 2 to 4 percent of people with ASD, the cause of the disorder is evidently genetic. A rare gene mutation or a defect in a specific chromosome can motivate the development of the condition in these cases. Oftentimes, cases like these are also associated with secondary effects, such as the distinctive facial features associated with ADNP.
How do these gene abnormalities lead to autism? In nearly all cases, these genes are involved in brain development in some way. They could be designed to affect the production of nerve cells or play a role in their growth and organization. If these neurons aren’t developed properly, or if certain types of cell-to-cell communication are inhibited, it could result in the signature impairments of ASD.
That said, there isn’t a known inheritance pattern for ASD. Researchers note that ASD does tend to run in certain families; if you have relatives with ASD, your children will be more likely to develop the condition. However, there’s never a guarantee, and there isn’t a clear pattern to observe (as is the case with something like male-pattern baldness).
There are also many other factors that could play a role in autism development, though the research is still unclear. Certain viral infections, medications, pregnancy complications, and even environmental hazards like air pollutants may all play a role in spurring the development of ASD.
One important thing to note is that there is no link between ASD and vaccines of any variety. The original study suggesting such a claim has been fully retracted and debunked by further research.
The Importance of Further Autism Research
One thing is certain: we need to research autism much further if we’re going to understand it and (eventually) treat it more effectively. This is an incredibly complicated disorder that affects millions of people, so the more resources we devote to researching and treating it, the better. Only through scientific advancement will we be better able to manage ASD.