Down Syndrome Extra 21 - Facts & Figures

Why does it occur?

Nobody knows why the presence of an extra chromosome no. 21 occurs but it can come from either the mother or father, however it is important to remember that it is nobodies fault and nothing could have been done differently to prevent it happening.

Down Syndrome occurs in all races, in all social classes and in all countries throughout the world. IT CAN HAPPEN TO ANYONE.

What are the different types of Down Syndrome?

Standard (Regular or primary) Trisomy 21

About 94% of all people with Down Syndrome fall under this group. This type of Down Syndrome is an accident of nature, it can happen to anyone and there is no known reason why it occurs. The parents have normal chromosomes but the baby has three rather than two chromosomes of the number pair 21.

Translocation

This type occurs in about 3% of babies with Down Syndrome. Part of the 21 chromosomes becomes attached to another chromosome so that both parts of the new large chromosome move close together as one.

In about half of the people with translocation it is a one off occurrence and does not mean that it will happen again in any future pregnancy.

In the other half, however, it occurs because one of the parents, though having a normal balanced chromosomal make-up, has one of the number 21’s ‘stuck on’ to another chromosome. In this case the chance of having another child with Down Syndrome is quite high. Blood tests can be taken to find out more detailed information.

Mosaicism

This type of Down Syndrome is also rare – only about 2 – 3% of people with Down Syndrome fall into this category. In Mosaic Down Syndrome the cells with the extra 21 chromosome are mixed with the other normal cells. In other words only a certain percentage of the cells are affected.

What are the common symptoms & characteristics?

While Down Syndrome is chromosomal disorder, a baby is usually identified at birth through observation of a set of common physical characteristics. Babies with Down Syndrome tend to be overly quiet, less responsive, with weak, floppy muscles. Furthermore, a number of physical signs may be present. These include:

Flat appearing face
Small head
Flat bridge of the nose
Smaller than normal, low-set nose
Small mouth, which causes the tongue to stick out and to appear overly large
Upward slanting eyes
Extra folds of skin located at the corner of each eye, near the nose
Rounded cheeks
Small, misshapen ears
Small, wide hands
An unusual, deep crease across the centre of the palm (simian crease)
A malformed fifth finger
A wide space between the big and the second toes
Unusual creases on the soles of the feet
Overly flexible joints (sometimes being referred to as double jointed)
Shorter than normal height

Statistics...did you know?

Two babies with Down syndrome are born every day in the UK.
Around one in every 1,000 babies born will have Down syndrome.
There are 60,000 people in the UK with the condition.
Although the individual chance of a baby having Down syndrome is higher for older mothers, more babies with Down syndrome are born to younger women, reflecting the higher birth rate in this group.
Down syndrome is caused by the presence of an extra chromosome in a baby’s cells. It occurs by chance at conception and is irreversible.
Down syndrome is not a disease. People with Down syndrome are not ill and do not “suffer” from the condition.
All people with the syndrome will have a varying degree of learning difficulty. However, the majority of people with Down syndrome will walk and talk and many will read and write, go to ordinary schools and lead fulfilling, semi-independent lives.
Today, with the right support, people with Down syndrome can enjoy a life of sixty years plus.

Some common myths

People with Down syndrome don't live very long. Today, people with Down syndrome can look forward to a life of 60 years plus.
Only older mothers have babies with Down syndrome. Although older mothers have a higher individual chance of having a baby with Down syndrome, more are born to younger mothers, reflecting the higher birth rate in this group.
People with Down syndrome cannot achieve normal life goals. With the right support, they can. The vast majority of people with Down syndrome learn to walk and talk, and many are now attending mainstream schools, passing GCSEs and living full, semi-independent adult lives.
People with Down syndrome all look the same. There are certain physical characteristics that can occur. People with Down syndrome can have all of them or none. A person with Down syndrome will always look more like his or her close family than someone else with the condition.