What is Down syndrome?

Down syndrome is a chromosomal condition related to chromosome 21. It affects 1 in 800 to 1 in 1000 live born infants.

People who have Down syndrome have learning difficulties, mental retardation, a characteristic facial appearance, and poor muscle tone (hypotonia) in infancy.

Individuals with Down syndrome also have an increased risk for having heart defects, digestive problems such as gastroesophageal reflux or celiac disease, and hearing loss. Some people who have Down syndrome have low activity of the thyroid gland (hypothyroidism) - an organ in the lower neck that produces hormones.