While Down syndrome is common, the symptoms an individual experiences can vary. Some people may have many symptoms; others only a few. Some people will have very severe symptoms, and others can have mild ones.
Common characteristics include:
- A flat facial profile
- An upward slant to the eye
- A short neck
- Abnormally shaped ears
- White spots on the iris of the eye (called Brushfield spots)
- A single, deep transverse crease on the palm of the hand
- Smaller than average size
- Exaggerated space between the first and second toes
- Poor muscle tone (called hypotonia)
- Joint looseness
- Broad feet with short toes
- Learning disabilities.
Besides the physical characteristics, people with Down syndrome are also at increased risk of developing certain medical conditions that come with their own set of symptoms. Some of these conditions can include:
- Thyroid problems
- Hearing problems
- Congenital heart disease
- Eye problems
- Seizure disorders
- Bone, muscle, nerve, or joint problems
- Leukemia and other cancers
- Immune system problems
- Developmental delay
- Mental retardation
- Alzheimer's disease.
(Click Down Syndrome Effects to learn more about this topic.)
A diagnosis can be made during prenatal testing. Diagnosing Down syndrome can also be done shortly after birth. In this case, the doctor may suspect that a baby has the condition based on the presence of possible characteristics of the disorder. The diagnosis is confirmed with a special blood test.