ABSTRACT
I PATHOPHYSIOLOGY OF ANKYLOSING SPONDYLITIS Ankylosing spondylitis is an inflammatory enthesopathy that has a predilection for males. It does not follow simple Mendelian genetics, but the predisposition to the disorder is inherited. Many, but not all, patients with ankylosing spondylitis are HLAB27 positive. Conversely all individuals who are HLA-B27 positive do not develop this disorder, indicating variable penetration and the role of yet unknown environmental factors that modulate the expression of the genetic substrate.
