DS is still young, so probably IABU, but I would welcome opinions because I would hate to find out a few years down the line that I had spotted warning signs and ignored them.
So, DS is 3 and knows all lowercase and uppercase letters, although not fluently. His nursery teacher told me last week that he is beginning to spell CVC words phonetically with wooden letters (obv does not yet have the coordination to write). I surprised because although I know he knows the letters, I thought it would be too early for anything more (I learnt to read at 6.5).
I have noticed a few times over the last 2/3 months that he mixes up letters (and sometimes numbers) that look the same/similar in different orientations. Some examples: n/u, d/b/p/q, e/G.
Now, the question is, is it normal at this stage (even though he is beginning to spell) or should we look into having him checked out by a professional?
He is otherwise quite bright (e.g. can count to 20, knows number symbols and can relate them to quantities, can find the missing digit in sequences such as 4-5-?-7, etc) but not the very top of the class.