Teaching Tuesday: Physical Features of Down Syndrome

"FYI:  My anatomy does not dictate my worth"

Trisomy 21, or Down syndrome is often referred to as a "visual" disability as those with an additional copy of the 21st gene can share many physical characteristics. The extra chromosome may affect many body systems, or not; it does not just affect mental functioning and facial features. Those with Down syndrome may have few or all of the characteristics listed here. Having some or almost none of these characteristics does not indicate the "degree" of Down syndrome one may or may not have. It is worth noting that there is no such thing as a "mild" or "severe" case of Trisomy 21; one either has it or they do not.

Head and Facial Structure

People with Down syndrome can have Microgenia or a smaller than average chin, overall broadened and flattened facial features and possibly a shortened neck. One of the most recognizable features of Down syndrome are upturned almond shaped eyes with epicanthic folds. A flattened nasal bridge is also common, as well as macroglossia or an "enlarged" protruding tongue (due to both size of the tongue and a smaller oral cavity) and Brushfield spots (white or grey spots on the iris). The ears are often smaller in size and low set. Teeth can be irregularly formed, sized and placed in the skull incorrectly.

For more complications of the eye arising from Down syndrome, please consult Eye Problems Frequently Experienced with Down Syndrome. For more complications of the ear arising from Down Syndrome, please consult Hearing Complications with Down Syndrome.

Musculoskeletal

Most people with Down Syndrome have an overall shorter height and tend towards being more overweight than their peers. Commonly, there is a shortening of the femurs or humerus bones or both, causing the legs or arms to be smaller than normal. Often there is brachycephaly or a flattened skull. Hypotonia or poor muscle tone is common, as is hypermobility or the ability to flex certain joints beyond their normal range (this may not affect all joints). Related to this is a potentially dangerous condition known as Atlanto-axial Instability where there is a looseness between the fist and second vertebrae. It is also not uncommon for people with Down syndrome to have diastasis recti or a separation in the abdominal muscles. Umbilical hernias are also frequently seen.

Hands and Feet

A single palmar crease or simian crease is very common, as is "sandal foot" or the presence of a larger than normal space between the great and second toe. Short fingers, an increased amount of ulnar loops in the fingerprints and a kink or bend of the little finger towards the hand (known as clinodactyly) are also common.

Many people with Down syndrome also have congenital heart issues as well as problems with the digestive and other organ systems. Although considered a "visual disability" by some, Down syndrome can many aspects of the body that may not be readily noticeable.  Many of these traits are best viewed as quirks and have little to no impact on quality of life at all.