Autism is a very complex disorder that has a wide spectrum of severity. Some of the broader symptoms used to diagnose autism, per The National Institute of Mental Health, are:
- Ongoing social problems that include difficulty communicating and interacting with others
- Repetitive behaviors as well as limited interests or activities
- Symptoms that typically are recognized in the first two years of life
- Symptoms that hurt the individual’s ability to function socially, at school or work, or other areas of life
Individuals with autism can also suffer from a variety of physical ailments, such as difficulty sleeping and digestive trouble.
Pica in Autism
Due to the physical and mental effects of autism, some individuals eat objects with no nutritional value, such as dirt, which is a disorder called pica. Pica is prevalent among individuals with autism, although there are no concrete numbers about the percentage of autistic individuals with pica.
There are a variety of theories as to why pica is so prevalent in individuals with autism. One thought is that, especially in cases of severe mental deficit, the individuals have difficulty discerning edible objects from inedible ones. Another theory is that individuals are lacking certain vitamins and minerals because they cannot tolerate some foods or because their bodies are unable to properly absorb nutrients from their food, which is why they would eat mineral-rich things like dirt.
Zinc Deficiency in Autism
Many individuals with autism have a deficiency in zinc, but it has a very complicated role in autism. Some studies attribute zinc deficiency to the development of autism while others cite it as a result of improper diet in individuals with autism.
Zinc could lead to autism because it is a key mineral for growth and development as well as immune function, so deficiency could lead to improper development, leading to autism. It could be a result of autism because of the gastrointestinal distress discussed earlier. Scientists have also found a genetic mutation that could contribute to zinc deficiency, and, therefore, to autism.
Mutations in ATP7B Gene
There is a gene called ATP7B that, when it is faulty in both copies of the gene, leads to Wilson’s disease, which is a disease of copper toxicity. When only one of the copies of the gene is mutated, there is less significant pathology, but it is hypothesized that copper overload of babies in utero could inhibit brain development and lead to autism.
The ATP7B gene codes for a channel that moves copper in and out of cells, and when it isn’t working right, copper can’t leave the cells. Copper and zinc compete for binding spots in the cell, so when there is excess of copper, it binds all of the spots and leaves zinc just floating in the cell.
The cell sees the zinc as being in excess, because it is not bound to anything, and excretes it. This leads to loss of zinc, which leads to the zinc deficiency that could cause improper development of the brain, which could lead to autism.
This zinc deficiency would not only be present in utero, but throughout the individual’s life. This genetic mutation, coupled with gastrointestinal difficulty and/or an inability to discern edible objects from inedible ones, could contribute to the prevalence of pica in autism.
