37 Powerful Facts about Down Syndrome

By Madeline Thatcher, Associate Writer

Published May 20, 2019

Down syndrome is a chromosomal defect disorder, meaning a mutation occurs on one of the 46 chromosomes that exist in human cellular structures._[4]
Down syndrome is caused by having an extra chromosome 21._[4]
About one in every 700 babies born in the United States has Down syndrome._[3]
Down syndrome causes mild to moderate intellectual disability. It is the most common cause of this type of disability._[4]
The first recorded scientific observation of Down syndrome was made by John Langdon Down in 1866._[6]
The condition was initially referred to as “mongolism,” and Down syndrome did not become the official name until the 1970s._[6]
The term “mongolism” came from the upward-slanting eyes of people born with Down syndrome, which some saw as similar to eye shape common in Asia._[2]

While there are common features for those with Down syndrome, mental ability varies between people.

Common characteristics of Down syndrome include low muscle tone, small stature, upward-slanting eyes, and a single deep crease across the center of the palm._[3]
There is no link between the severity of Down syndrome and the severity of abnormal physical characteristics displayed._[7]
Down syndrome was termed a chromosomal abnormality in 1959 by Jerome Lejeune, who discovered the extra chromosome 21 in patients with the condition._[6]
There are three main types of Down syndrome: trisomy 21, mosaicism, and translocation._[3]
Trisomy 21 is the most common type of Down syndrome, with over 95% of cases falling into this category. It is caused when an embryo develops three copies of chromosome 21 instead of two._[3]
Translocation Down syndrome is present in 4% of cases and does not include an extra chromosome in cell structure. Instead, it occurs when a partial or complete copy of chromosome 21 attaches itself to another chromosome._[3]
Mosaicism is the least common form of Down syndrome, accounting for only 1% of cases. Mosaicism is caused when cells with the normal amount of chromosomes and cells with an added chromosome mix and replicate a chromosome 21 in the latter._[3]

Women who give birth to a child with Down syndrome have a higher chance of having another Down syndrome child.

Both mothers and fathers can contribute the extra chromosome 21 to their fetus, but in 95% of cases, it is the mother._[3]
Down syndrome is not considered hereditary, since only 1% of cases show the condition passing from parent to child._[3]
Types of prenatal screenings can now determine if a fetus will have Down syndrome. These tests are usually conducted using a blood sample and an ultrasound._[3]
In order to accurately determine if Down syndrome is present, doctors perform a karyotype, a chromosomal analysis that indicates which chromosomes may be abnormal._[3]
Until the mid-1950s, hospitals and doctors encouraged parents to give children with Down syndrome to an institution by insinuating it would be too difficult to care for their child and their needs._[6]
In 1960, the average life expectancy of a person with Down syndrome was 10 years. By 2007, the average had risen to 47 years._[2]
In 1982, a baby nicknamed “Baby Jane Doe” was born with Down syndrome as well as esophageal atresia. Doctors and parents argued the right to deny the child life-saving medical surgery because of the baby’s Down syndrome._[6]
The death of Baby Jane Doe incited a massive campaign to ensure fetuses and babies born with Down syndrome were protected by child abuse laws. Legislation was passed in 1984 to officially protect them and their rights to life-saving medicine._[6]

In the past, people with Down syndrome usually died early in life, but recent medical and cultural responses have increased their average life span.

The only known link to increased likelihood of Down syndrome is higher maternal age. However, because younger women give birth more often than older women, 80% of children with Down syndrome are born to women under 35._[3]
Women who give birth to a baby with Down syndrome have an increased chance of having a second child with the same condition (from 1 in 700 to about 1 in 100)._[3]
Between 1979 and 2003, the statistical likelihood of having a baby with Down syndrome increased by 30%._[2]
Babies born with Down syndrome and weighing less than 3.3 pounds are 24 times more likely to die in the first month of life._[2]
About 50% of all babies with Down syndrome are born with a congenital heart defect, which increases the chance of an earlier death._[2]
Up to 75% of people with Down syndrome have some hearing loss._[2]
Ear infections and eye diseases are very common in people with Down syndrome._[2]
Children with Down syndrome usually have poor short-term auditory memory skills, meaning they may struggle to remember things others have said to them._[7]

When you focus on someone's disability you'll overlook their abilities, beauty and uniqueness. Once you learn to accept and love them for who they are, you subconsciously learn to love yourself unconditionally.

- Yvonne Pierre

Medical care for children with Down syndrome between birth and four years of age costs 12 times more than medical care for unaffected children._[2]
About 40% of families who cared for a child with Down syndrome reported financial struggles because of it._[2]
A Flemish painting called The Adoration of the Christ Child may depict an angel with Down syndrome. Evidence like this suggests Down syndrome is not a recent phenomenon, despite only being accurately described in detail fairly recently._[5]

Black children with down syndrome have shorter life spans than white children.

Black children born with Down syndrome have a lower life expectancy than their white counterparts._[2]
Increased access to abortion coincides with a decrease in babies born with Down syndrome._[5]
Of the 500 million people estimated to live with a disability, 80% live in developing nations. These statistics are also true for Down syndrome._[8]
Madeline Stewart, 21-year-old model and fashion designer, was the first person with Down syndrome to become a professional working model._[1]