The number one warning sign for dyslexia is spelling issues. If you can't decode words to read them you won't be able to decode them to spell either.
IDEA definition of Specific Learning Disability is as follows...
Specific Learning Disability
(A) IN GENERAL.–The term 'specific learning disability' means a disorder in 1 or more of the basic psychological processes involved in understanding or in using language, spoken or written, which disorder may manifest itself in the imperfect ability to listen, think, speak, read, write, spell, or do mathematical calculations.
(I underlined and used boldface for the word spell)
Spelling usually falls under written expression and written expression sadly is harder to get services for however if your child is having reading issues and has an IEP there should also be a goal about spelling.
By now you probably know my feelings about Kelli Sandman-Hurley from the Dyslexia Training Institute. Kelli has been doing a lot of work in the area of spelling as of late and if you have not already liked their page, you can find it here. She posts a lot of information about teaching spelling. Kelli recently posted this on their facebook page:
You know what really chaps my hide? When accommodations are put into place instead of teaching. Spelling is the best example. Spelling is the hardest skill a student with dyslexia will learn, and it is quite possible the most important. Yet, we give shorter spelling tests, or no spelling tests, exempt students from spelling instruction or give them an app or computer. Now I am a huge proponent of accommodations, but not in place of teaching these bright kids how to think about language. We need to show them how to understand the language and how to solve the mystery of troublesome spellings. I don’t want to accommodate away a skill that as important as spelling. If you can read a word, it does not mean you can spell it, but if you can spell (and understand the spelling) of a word, you can read it...
But what if your child doesn't have an IEP. What if when your child takes the universal screener required for RTI they score just above the 25th percentile in reading but your child can't spell, doesn't understand correct punctuation and capitalization? Then what do you do?
I wish I had some magic idea for you but sadly I don't. Written Expression is hard to fight for but if you do your research, save all your child's work, keep a journal of your child when doing homework, you can try to make the point of where the issues are.
There is such a thing as a spelling learning disability, most times it is called Dyslexia.