The Kerala Assembly was informed on Wednesday that five lakh people suffer from ankylosing spondylitis (AS) in the state and a detailed survey would be done to identify and treat these patients. Even though the cause of ankylosing spondylitis is not known it has been identified as a variant of rheumatoid arthritis in which there is a long-term inflammation of the joints of the spine. This issue was brought before the House by CPI-M legislator Murali Perunelli who explained how 29-year-old off-beat filmmaker Sijo Kannanaikkal whose recent film on Kathakali won appreciation across the globe was suffering from this ailment.