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.
Normal human Karyotype. Down syndrome is a chromosomal abnormality characterized by the presence of an extra copy of genetic material on the 21st chromosome, either in whole (trisomy 21) or part (such as due to translocations).