Down Syndrome
By the Numbers

1 - Down syndrome is the number one chromosomal birth defect.

1862 - The year that Dr. John Langdon Down first characterized Down syndrome.

21 - The number of the chromosome normally affected by Down syndrome.

1959 - The Year that Dr. Jerome Lejeune discovered that it was an extra 21st chromosome that caused Down syndrome

3 - The number of chromosome 21 copies most people with Down syndrome have.

350,000 - The number of people in the United States living with Down syndrome.

56 - The average number of years a typical person with Down syndrome will live.

100 - The percent of people with Down syndrome that are capable of leading full, productive lives.