Characteristics and Features of Down Syndrome

Young girl with down syndrome
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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. The purpose of listing the features of Down syndrome 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.

This list of issues can help you understand what your child might be facing so that you can be proactive in his or her care.

The Features of Down Syndrome

People with Down syndrome have some distinctive facial and physical features, medical problems, and cognitive impairments in common. It's 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 his or her own unique personality and strengths.

Physical Features

Some of the physical features that people with Down syndrome have include:

  • Distinct facial features: Infants with Down syndrome have some specific facial features that 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 somewhat larger tongue, a short neck, white flecks in the colored part of their eyes, 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.
  • Differences in 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.

    Medical Problems

    In addition to their facial and physical features, children with Down syndrome are at higher risk of developing a number of medical problems. Many individuals don't have any medical issues, but it's important to be aware of potential ones that your child could face if he or she has Down syndrome. These potential medical problems include:

    • Hypotonia 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 problems: Up to 60 percent of children with Down syndrome will have some type of vision problem. Vision problems can include nearsightedness, farsightedness, crossed-eyes, cataracts, and blocked tear ducts. Fifty percent have vision problems that require glasses.
    • Hearing problems: Up to 75 percent of babies with Down syndrome will have some form of hearing loss. Most infants in the U.S. are screened for hearing loss shortly after birth. Although rarely is an infant with Down syndrome completely deaf, it's still important to detect any hearing loss since hearing plays a large role in language development.
    • Ear infections: Between 50 percent to 75 percent of children with Down syndrome have ear infections.
    • Heart defects: About 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 your child doesn't have a heart defect (problem with the structure of the heart) at birth, he or she won't develop a heart defect later in life.
    • Other medical problems: Some children with Down syndrome will have gastrointestinal defects. Most of these malformations can be fixed with surgery, but other potential complications that can develop are heartburn, GI blockage, and celiac disease. Thyroid issues and anemia are also more common. Fifty percent to 75 percent have sleep apnea, and obesity is more likely too. Younger children with Down syndrome have a 1 percent higher chance of developing leukemia, a type of cancer that affects the white blood cells in the body.

      Intellectual Disability 

      All individuals with Down syndrome have some degree of intellectual disability, formerly called mental retardation, or developmental delay. They're not incapable of learning, they just tend to learn more slowly and have more trouble with complex reasoning and judgement. It's impossible to predict the degree of intellectual disability 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's easy to list the features and symptoms of people with Down syndrome, it's impossible to capture all of the characteristics that make them unique. It's important to remember that people with Down syndrome are individuals first and their diagnosis is secondary.


      Centers for Disease Control and Prevention (CDC). Down Syndrome: Data and Statistics. Updated June 27, 2017.

      Eunice Kennedy Shriver National Institute of Child Health and Human Development. What Are Common Symptoms of Down Syndrome? Office of Communications. U.S. Department of Health and Human Services. National Institutes of Health. Updated January 31, 2017.

      Mayo Clinic Staff. Down Syndrome. Mayo Clinic. Updated June 27, 2017.