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 a person with Down syndrome may face.
Almost all infants with Down syndrome have low muscle tone (hypotonia). This means that their muscles are somewhat weak and they appear “floppy.” This is important because muscle tone can affect a child with Down syndrome’s ability to learn and grow. Low muscle tone came make it more difficult to learn to roll over, sit-up, stand and even talk. In newborns, hypotonia can also cause feeding problems.
Many children with Down syndrome are delayed in reaching their motor milestones because of their hypotonia. Hypotonia cannot be cured but it generally improves over time. Physical therapy is usually started early in babies with Down syndrome to improve their muscle tone. Hypotonia can also lead to some of the orthopedic problems (bone problems) that some people with Down syndrome can have.
Approximately 70% of children with Down syndrome will have some type of vision problem such as nearsightedness (myopia), farsightedness (hypermetropia), crossed-eyes (strabismus) and even blocked tear ducts (naso- lacrimal duct obstructions). It is very important that children with Down syndrome have early eye exams since the majority of these vision problems are correctable.
About 40% of babies with Down syndrome are born with heart defects. Some of these heart defects are mild and may correct themselves with no medical intervention. Other heart defects are more severe, and may require surgery or medication, and complex medical management.
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.
About 10% of infants with Down syndrome will have gastrointestinal issues such as a narrowing or blockage of the intestines (duodenal atresia), an absent anal opening (anal atresia), an obstruction of the outlet of the stomach (pyloric stenosis), or an absence of the nerves in the colon called Hirschsprung’s disease. Most of these malformations can be fixed with surgery.
People with Down syndrome can also have problems with their thyroid gland, which is a small gland located in the neck. Usually people with Down syndrome have too little thyroid hormone, a condition called hypothyroidism. Hypothyroidism is most often treated taking replacement thyroid hormone. This medication must be taken for the rest of the person’s life.
Very rarely, about 1% if the time, an individual with Down syndrome can develop leukemia. Leukemia is a type of cancer that affects the white blood cells in the body. Some of the symptoms of leukemia include easy bruising, tiredness, looking pale and having unexplained fevers. Although leukemia is a very serious disease, more and more children are surviving (over 90%). Typically, leukemia is treated with chemotherapy or radiation. Occasionally a bone marrow transplant is performed.
All individuals with Down syndrome have some degree of mental retardation. They learn more slowly and have difficulties with complex reasoning and judgment, but they do have the capacity to learn. It is impossible to predict the degree of mental retardation in an infant with Down syndrome at birth (just as it is impossible to predict the IQ of any infant at birth).
There is a wide range of mental abilities among people with Down syndrome (and among people in the general population). IQ stands for ”intelligence quotient” and is a number used to express the relative intelligence of a person. The IQ range for “normal” intelligence is between 70 and 130. A person is considered to have mild mental retardation if his IQ is between 55 and 70. A moderately mentally retarded person has an IQ of between 40 and 55. Most individuals with Down syndrome score within the mild to moderate range of mental retardation.
Perhaps more important that IQ scores is the fact that individuals with Down syndrome can learn. There is often a misconception that individuals with Down syndrome have a “static” or predetermined ability to learn. This simply is not true. It is now known that individuals with Down syndrome develop over the course of their lifetime and should be treated accordingly. The learning potential of an individual with Down syndrome can be maximized through early intervention, good education, higher expectations and encouragement.
Stray-Gunderson, K., Babies with Down Syndrome - A New Parents Guide, Woodbine House, 1995.
Chen, H., Down syndrome, Emedicine, 2007