While letter reversal is one of the signs of dyslexia, many more signs of the disorder have to exist for a child to be diagnosed as dyslexic. Any questions you have about dyslexia can probably be answered by visiting the International Dyslexia Association website.
Become concerned about reversals only if your son continues to reverse letters after he has had considerable instruction in the left-to-right direction in both reading and writing. Then, if he is having difficulty learning to read, the possibility of a reading problem should be investigated.
In the meantime, the best way to ensure that your son becomes a good reader is to read to him every night. You should also be listening to him read the stories that he is working on at school. It may make it easier for him to read if you have him draw a finger across the page under each word as he reads it.
Praise is another important component in helping young children learn to read. When your child reads to you, find something good to say about his efforts. And try to keep reading fun so he will enjoy reading to you.
To keep on top of how well your son is learning to read in first grade, keep in close touch with his teacher. Then, any problems can be resolved before they become serious.