It is a responsibility of school to help a child no matter what the individual differences are. I had one child who could read by age 5 but the schools were not structured to deal with this difference which produces a problem for child and parents.
Reading is a complex cognitive process that requires many different parts of the brain to reach a stage of maturity in order for the process to occur.  Reading does not involve the same neural processing for all people. I had another child that had a difference processing method which again produced a problem for child and parents because the schools were not equipped to deal with differences. While she graduated near the top of her class and is now in graduate school programs that are structured to help the child would have likely increased her learning.