Asymptomatic AS refers to a condition where a person has ankylosing spondylitis but does not experience any noticeable symptoms. While asymptomatic AS may not cause pain or functional impairment, it can still lead to structural damage of the spine and other areas over time if left untreated. Screening family members of people diagnosed with AS can help identify cases of asymptomatic AS to provide early treatment that may help slow progression of the disease.