This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
HLA - B27 is associated with - 
Select and explain. 
A. Ankylosing spondylitis, B. Rheumatoid arthritis, C. Chronic active hepatitis, D. Diabetes
A: Ankylosing spondylitis
Answer: A: Ankylosing spondylitis 
Explanation: A variety of diseases have been found to be associated with certain HLA alleles.
The best know is the association of HLA-B27 with ankylosing spondylitis (AS), individuals who inherit this allele have a 90 fold greater chance of developing AS than those who are negative for HLA - B27.