What Are the Features of Down Syndrome?
Every syndrome has physical and medical features that define it. Some of these features are just traits that are observed to occur more frequently in people with that specific syndrome, and some of the features are more serious medical problems.
People with Down syndrome have some distinctive facial and physical features, medical problems and cognitive impairments in common. It is important to remember that no one person with Down syndrome will have all of the features described here. Nor does the number of physical problems a person with Down syndrome has correlate with their intellectual capability. Each and every child with Down syndrome has their own unique personality and strengths.
The purpose of listing these features is not to frighten or overwhelm you, but to give you an idea of the wide range of features that can be seen in people with Down syndrome. No individual person with Down syndrome will have all of the features described and not all of the features described are of medical importance. This list of issues is just to help you understand what your child might be facing and to help you be proactive in their care.
Infants with Down syndrome have some distinct facial features which can cause them to resemble one another to a small degree. These features can include small upturned eyes, a small, somewhat flat nose, a small mouth with a with a somewhat larger tongue, and small ears. They also tend to have rounder faces with flatter profiles. Obviously, none of these features is of medical importance but they are what make people with Down syndrome recognizable.
Hands and Feet
Some of the physical features seen in people with Down syndrome include differences in their hands and feet. Instead of two creases across their palms, people with Down syndrome frequently have a single crease, short stubby fingers and a fifth finger that curves inward (clinodactyly). They can have small feet with a larger than normal space between the big and second toes. Once again, none of these features is medically important, but these features are some of the clues that can help a physician make the diagnosis of Down syndrome.
In addition to their facial and physical features, children with Down syndrome are at higher risk to develop a number of medical problems. Many individuals with Down syndrome have no medical issues, but it is important to be aware of what issues an individual with Down syndrome might face.
Hyptonia or Low Muscle Tone
Almost all infants with Down syndrome have low muscle tone or weak muscles. This condition is called hypotonia. Low muscle tone came make it more difficult to learn to roll over, sit-up, stand and even talk. Hypotonia cannot be cured but it generally improves over time and is treated with physical therapy.
Vision and Hearing Problems
Most children with Down syndrome will have some type of vision and hearing problems. Vision problems can include nearsightedness, farsightedness, crossed-eyes and even blocked tear ducts. Somewhere between 40-60% of babies with Down syndrome will have some form of hearing loss. Most infants in the US are screened for hearing loss shortly after birth. Although rarely is an infant with Down syndrome completely deaf, it is still important to detect any hearing loss since hearing plays a large role in language development.
A little less than half of all babies with Down syndrome are born with heart defects. These defects can range from mild to more severe and even life-threatening. Some of the mild heart defects may correct themselves over time, while more severe heart defects require medications or surgeries. If a child does not have a heart defect (problem with the structure of the heart) at birth, it will not develop a heart defect later in life.
About 10% of infants with Down syndrome will have gastrointestinal defects. Most of these malformations can be fixed with surgery. People with Down syndrome can also have problems with their thyroid gland and need to take thyroid medication. Very rarely, about 1% of the time, people with Down syndrome can develop leukemia - a type of cancer that affects the white blood cells in the body. Typically, leukemia is treated with chemotherapy or radiation and over 90% of people diagnosed with this condition are cured with treatment.
All individuals with Down syndrome have some degree of mental retardation or developmental delay. They are not incapable of learning, they just tend to learn slower and have more trouble with complex reasoning and judgement. It is impossible to predict the degree of mental retardation in an infant with Down syndrome at birth. The learning potential of an individual with Down syndrome can be maximized through early intervention, good education, higher expectations and encouragement.
Individuals not Diagnoses
While it is easy to list the features and symptoms of people with Down syndrome, it is impossible to capture all of the characteristics that make them unique. It is important to remember that people with Down syndrome are individuals first and their diagnosis is secondary.
Stray-Gunderson, K., Babies with Down Syndrome - A New Parents Guide, Woodbine House, 1995.
Chen, H., Down syndrome, Emedicine, 2007