Children with Down syndrome are often identified at birth as a result of the physical characteristics associated with the syndrome.
Some children exhibit only a few characteristics; others exhibit many. Because some of these features are also seen in people without Down syndrome, genetic testing must be done to confirm the diagnosis.
Other Health Problems Associated With Down Syndrome
As many as 50% of the children with Down syndrome are also born with heart defects. Some of these heart defects are major, and the child may experience heart failure shortly after birth. However, not all heart defects are immediately apparent. For this reason, all infants with Down syndrome should have an echocardiogram within the first few months of life to check for heart problems. The minor defects may be manageable with medications while the major ones may require surgery.
People with Down syndrome also have more hormonal problems than the general population. About 10% of babies born with Down syndrome and as many as 50% of adults with Down syndrome have thyroid disease. The most common thyroid condition is hypothyroidism, slowing of the thyroid gland. Hypothyroidism can be easily treated with medication.
More than half the children born with Down syndrome also have visual problems such as crossed eyes, nearsightedness or farsightedness, or cataracts. In many cases, these problems can be treated with glasses or surgery. Hearing impairment is also very common. Children with Down syndrome should have regular vision and hearing tests so any such problems can be treated before they interfere with language development.
Individuals with Down syndrome have a 15-20 times greater risk of developing leukemia (although it is still uncommon), which generally begins in the first three years and has a high cure rate. A temporary form of leukemia is also seen in the newborn period that resolves spontaneously within the first two to three months of life.
Approximately 10%-12% of babies born with Down syndrome also have abnormalities in the gastrointestinal tract that require surgery for correction.
Approximately 25% of adults over the age of 35 with Down syndrome will show signs of Alzheimer's disease, a form of dementia. In the general population, Alzheimer's disease usually does not develop before age 50, and only 5%-10% of adults over 65 develop symptoms.