Causes of Ankle Pain. 1  Ankylosing Spondylitis Ankylosing spondylitis is a type of arthritis that causes chronic inflammation of the spine. 2  Arthritis Arthritis is inflammation of one or more joints. 3  Broken Bone (Types of Bone Fractures) A broken bone is a fracture.
Down syndrome is a chromosomal condition that is associated with intellectual disability, a characteristic facial appearance, and weak muscle tone (hypotonia) in infancy. All affected individuals experience cognitive delays, but the intellectual disability is usually mild to moderate.
Down Syndrome: Causes, Symptoms and Risks. Down syndrome is the most common birth defect in the United States. It was first described in 1866 and is named after John Langdon Down, the doctor who first identified the syndrome.