Is multiple schlorsis and ankylosing spondylitis related? what are chances that a person has both?

Dismal: both are autoimmune conditions with very different pathophysiology; to have both is not impossible but would be exceedingly rare;

Not related: MS is a neurologic disease caused by changes in the myelin covering sheaths on nerve fibers, allowing nerve impulses to 'short circuit'. Ankylosing spondyliitis is an arthritic condition affecting primarily the spine with gradual fusion of spinal segments altering one's posture. the two conditions are not at all related, though an individual could have both diseases.