Ankylosing spondylitis can curving of the spine and shoulders that have bent forwards cause breathlessness and chest pain?

Yes: It can cause those symptoms by restricting chest expansion or direct involvement of the lungs and/or the heart. These symptoms need to be evaluated so speak with your doctor.

Ankylosis spondyliti: Marked dorsal kyphosis is possible with severe ankylosing spondylitis and this can cause difficulty moving the chest in breathing and pain from the deformity.