Thousands of microvilli form a structure called the brush border that is found on the apical surface of some epithelial cells, such as the small intestines. (Microvilli should not be confused with intestinal villi, which are made of many cells.
Autism spectrum disorder has no single known cause. Given the complexity of the disorder, and the fact that symptoms and severity vary, there are probably many causes. Both genetics and environment may play a role. 1  Genetic problems. 2  Several different genes appear to be involved in autism spectrum disorder.
Autism has a number of causes, as you will read here. You can improve the life of your child, and even reverse autism, by correcting these causes. There are a number of reasons why children develop Autism Spectrum Disorders or ASD. Genetics may play a part. But the vast majority of the causes are not genetic, which means you can do something about them.