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.
a chromosomal abnormality in which there is an addition or loss of chromosomes within a set (e.g., 23 + 22 or 23 + 24). Down syndrome is most often the result of this kind of error. See monosomy, trisomy, and polyploidy.