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.
Occasionally, a child with autism may display an extraordinary talent in art, music, or another specific area. The cause of autism remains unknown, although current theories indicate a problem with the function or structure of the central nervous system. What we do know, however, is that parents do not cause autism.ccasionally, a child with autism may display an extraordinary talent in art, music, or another specific area. The cause of autism remains unknown, although current theories indicate a problem with the function or structure of the central nervous system. What we do know, however, is that parents do not cause autism.