Can incest cause the child to have speech problems and breathing problems And look like the brother?

Answer 1

Can incest cause the child to have speech problems and breathing problems?  Yes, but a LOT of other thing can do that do.

Look like the brother?  You many his/her Mam or Dad brother?  Yes it can, but a lot of us look like our Mam or Dad brother anyway(e.g. your Mam and her brother do have 50% of the same DNA you know)