Down syndrome is the most commonly occurring genetic condition. Individuals with Down syndrome have an extra, critical portion of the number 21 chromosome present in all, or some, of their cells. This additional genetic material alters the course of development and causes the characteristics associated with Down syndrome.

It is estimated that one in every 691 live births will result in a child with Down syndrome, representing approximately 6,000 births per year in the United States. There are approximately 400,000 individuals with Down syndrome in the United States today.

There is a wide variation in the abilities, physical development and behavior of individuals with Down syndrome. Each individual has their own unique personality, capabilities and talents. One should always use “people-first” language. For example: a newborn is a baby with Down syndrome, not a Down’s baby.

With appropriate education, therapy, social support and opportunity, the majority of individuals with Down syndrome will lead fulfilling and productive lives.

(Adapted from the NDSS page “What is Down syndrome?“)