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Section 2 - What is Down's syndrome and living with Down's syndrome?


What is Down’s syndrome?

Down’s syndrome is a genetic condition caused by an extra chromosome 21 in all or some cells. Down's syndrome is also known as trisomy 21, or T21.  A person with Down’s syndrome has 47 chromosomes instead of the usual 46. The extra chromosome cannot be removed from cells even if Down’s syndrome is diagnosed before the baby is born.

All women have a chance of having a baby with Down’s syndrome. Nothing you or the baby’s father have done or not done can make any difference to this chance.

All people with Down’s syndrome will have a learning disability. This means they may be delayed in their development and take longer to learn new things. There is a greater understanding these days of how children with Down’s syndrome learn, and help is provided in education settings. Around 80% (8 in 10) of children will go to mainstream primary schools, although individuals vary greatly in how they develop and will have different health and support needs. The antenatal tests cannot tell you what the health and support needs of your baby may be.

You can watch some family stories on living with Down’s syndrome here.

There are support organisations available for pregnant women and for families who have a child with Down’s syndrome. These include the Down’s Syndrome Association (DSA). Helpline 0333 12 12 300

Children and adults with Down’s syndrome

In Wales 90% (9 in 10) children with Down’s syndrome live past their 5th birthday.

For babies without serious health conditions survival is similar to that of other children, and most people with Down’s syndrome will live into their 60s. Most children and adults who have Down’s syndrome lead healthy and fulfilled lives and are included in their community. Most say they enjoy their lives and relationships. Many adults are capable of work and live in their own accommodation, with support.

Baby with Down

Toddler with Down


People born with Down’s syndrome are more likely than most to have some medical conditions.

  • In Wales about 60% (6 in 10) of children with Down’s syndrome will have a heart condition, and around 30% (3 in 10) will need an operation.
  • Most children with Down’s syndrome will have some sight difficulty that will need monitoring or treatment. More serious sight difficulty is less common, for example, 0.4% (1 in 250)  of children with Down’s syndrome are born with cataracts.
  • Around 60% (6 in 10) children with Down’s syndrome will have some hearing loss which may cause challenges with speech and language.
  • Infections of the ears, nose and throat are more likely.
  • Leukaemia is more common in children with Down’s syndrome and for most this will not cause any health conditions. 0.5%  ( 1 in 200) children with Down’s syndrome will need treatment for leukaemia. Following treatment, most children with leukaemia will recover with no related health issues.

Babies and children with Down’s syndrome will be under the care of a specialist medical team who will be aware of the increased chances of these medical conditions and will do tests to monitor their wellbeing. Many of these conditions can be treated effectively.