Learn how to watch out for and treat hypothyroidism, a common medical issue in children with Down syndrome.

National Down Syndrome Society

Individuals with Down syndrome have a higher incidence of endocrine problems than the general population does. The endocrine system comprises a set of glands that include the thyroid, adrenal, and pituitary glands.

What is hypothyroidism?

Hypothyroidism results from a thyroid gland that malfunctions, decreasing the synthesis of the hormone thyroxin. Thyroxin is the hormone that promotes growth of the brain and other body tissue.

How common is hypothyroidism?

Hypothyroidism is the most common endocrine problem in children with Down syndrome. It is estimated that approximately 10 percent of children with Down syndrome have congenital or acquired thyroid disease. Studies of adults with Down syndrome vary widely, but the incidence of thyroid disease in adults with Down syndrome is believed to be between 13 and 50 percent. Hypothyroidism can occur at any time from infancy through adulthood.

How is hypothyroidism diagnosed?

All individuals with Down syndrome should be tested for hypothyroidism at birth and at periodic intervals (at least every two years) thereafter. The indicators of hypothyroidism -- enlarged tongue, constipation, poor circulation -- are also found in individuals who do not have hypothyroidism, so the blood test for thyroid function is an important diagnostic test. Because the thyroid hormone affects normal development of the brain, testing of infants is particularly crucial.

What treatment exists for hypothyroidism?

The thyroid hormone, thyroxin, is readily replaced through medication.

What is hyperthyroidism?

In this case, the thyroid gland is overactive rather than underactive (as it is with hypothyroidism). Symptoms include swelling in the neck, abnormal sweating, and rapid pulse rate. No evidence exists to suggest that hyperthyroidism is more prevalent in individuals with Down syndrome than in the general population.

What is the treatment for hyperthyroidism?

This thyroid malfunction can be treated pharmacologically, through medication that blocks the synthesis of the thyroid hormone. It can also be treated with radioactive compounds to destroy the gland, or by surgically removing a portion of the thyroid gland.

Are people with Down syndrome more prone to diabetes?

There is not sufficient data available at this point to know if children with Down syndrome have an increased risk of developing type 1 diabetes as compared with the rate for their peers in the general population. Research suggests, however, that individuals who develop one type of endocrine autoimmune disorder, such as thyroiditis, are more likely to develop a second disorder, such as type 1 diabetes.

Originally featured on National Down Syndrome Society (NDSS.org) and reprinted with permission. Copyright © 2012 Meredith Corporation.