The National Advocate for People with Down Syndrome Since 1979

National Down Syndrome Society
666 Broadway, 8th Floor
New York New York 10012
800-221-4602
info@ndss.org 

Down Syndrome

Featured ImageOne in every 691 babies in the United States is born with Down syndrome, making Down syndrome the most common chromosomal condition. Here you'll find an introduction to Down syndrome and an overview of related facts, myths and truths and our preferred language guide.

  1. What Is Down Syndrome?

    What Is Down Syndrome?Down syndrome occurs when an individual has a full or partial extra copy of chromosome 21. This section explains the science behind Down syndrome, how it is diagnosed, its history and social impact.

  2. Down Syndrome Facts

    Down Syndrome FactsLearn the basics behind Down syndrome and the more than 400,000 people in the United States who have Down syndrome.

  3. Myths & Truths

    Myths & TruthsToday there are still many misconceptions about Down syndrome and those who have it. This guide dispels some of the common myths about Down syndrome.

  4. Preferred Language Guide

    Preferred Language GuideHere you'll find a guide to the proper use of language when referring to Down syndrome and people who have Down syndrome.

  • Buddy Walk
  • NDSS Yourway
  • My Great Story