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.
By Dr Ananya Mandal, MD. Down syndrome or Downâs syndrome is a congenital condition caused by the presence of an additional copy of chromosome 21 in a personâs cells. This is also referred to as trisomy 21. Humans usually have 46 chromosomes in every cell, with 23 inherited from each parent.Due to the extra copy of chromosome 21, people with Downâs syndrome have 47 chromosomes in their cells.t was only in the mid-twentieth century, (the 1950s) that karyotype techniques were discovered, which could be used to help identify the shape and number of chromosomes. This led to the understanding that trisomy 21 was the cause of Downâs syndrome, a finding that was reported by Jerome JÃ©rÃ´me lejeune in. 1959