The problem with the term dyslexia is that is covers so many variations of a way of learning and processing information. There are a million different sources with a million different ideas. My thoughts are that is is just a way in which the mind in some people works. I have 9 kiddos and each one has issues at different levels. I don't like the term learning disability because they are not disabled just different. The trick if finding what works for the individual.
A lot will depend on how old this child is. It is very hard to diagnose anything if the child is under 7. Developmentally sometimes reading is hard until a child is older than 7 but by 7 they should pick out the letters OK. Letters may move around on a page for any child until about 7 and writing letters and numbers backwards can be very common.
If the child is in school, the schools tend to try to label right away. In the case of dyslexia it is dangerous to diagnose to early. Remember this is not an illness just a learning style. It is hard to remember that when talking to teachers, counselors, and doctors. I found that the book that helped me the most was a book called: The Gift of Dyslexia. The first half of the book opened my mind into how this type of mind works and thinks. The second half of the book offers a trick to fix dyslexia. I did not find that part helpful at all. I also trust the information gathered about the dyslexic from that same author at this website: http://www.dyslexia.com/library/symptoms.htm
We struggle with reading issues and comprehension issues and even with one child writing issues. I still find that my children are very smart and I try to encourage learning in spite of their issues. I think that the hardest thing is the self esteem issues and not the actually learning. We try to keep in mind every day that our goal is heaven and any thing else is just gravy. I find comfort in knowing that there will be no reading test to get into heaven. I think they still need to learn to read but being kind to others is the most important, even in learning how to read. I hope this helps. I wish I had more time to write stuff but that website should be a good vantage point to take off from.