Physical Characteristics

Because a person with mosaic Down syndrome has a percentage of cells with the extra 21 st chromosome associated with Down syndrome, individuals can exhibit some or all of the physical characteristics associated with Down syndrome. In most cases, these individuals have fewer of these features or they are less prominently visible.

It is important to remember that the general population can exhibit these types of characteristics. It is when more than one of these characteristics is found in a person that more investigation is needed to determine if the individual has extra chromosomes.

Head and Face:

Back of head flat in line with neck

Excess skin or webbing around neck

Small low-set ears

Straight, fine hair

Flat nasal bridge

Epicanthal folds (a fold of skin in the inside corner of the eye)

Almond shaped eyes (often related to those of Asian descent)

Brushfield spots (white flecks on the colored part of the eye)

Late eruption of baby teeth and adult teeth

Protruding tongue

Hands and Feet:

Single crease across one or both palms

Short fingers

Single flexion furrow on fifth finger (one knuckle instead of two)

Short toes

Large space between first and second toe

Additional Features:

Short in stature

Unusually dry skin

Low muscle tone at birth