Down's syndrome, also known as Down syndrome, is a genetic condition that typically causes some level of learning disability and a characteristic range of physical features.

Most babies born with Down's syndrome are diagnosed with the condition after birth and are likely to have:

  • reduced muscle tone leading to floppiness (hypotonia)
  • eyes that slant upwards and outwards
  • their palm may have only one crease across it (palmar crease)
  • a below average weight and length at birth

Although children with Down's syndrome share some common physical characteristics, they do not all look the same. A child with Down's syndrome will look more like their mother, father or other family members than other children with the syndrome.

People with Down's syndrome also vary in personality and ability. Everyone born with Down's syndrome will have a degree of learning disability. The level of learning disability will be different for each individual.

Read more about the characteristics of Down's syndrome.

Screening for Down's syndrome

In some cases, babies with the condition are identified before birth as a result of antenatal screening for Down's syndrome. If screening indicates there is a chance your baby has Down's syndrome, further testing is available to determine how likely it is.

Screening tests don't tell you for definite if your baby has Down's syndrome, but they can tell you how likely it is. The only way to get a definite diagnosis is for a chromosome test to be done using a sample of the baby's blood.

Read more information about how Down's syndrome is diagnosed.

Who is affected?

Down's syndrome is one of the most common genetic causes of learning disability. Around 750 babies are born with the condition each year in the UK. Down's syndrome affects people of all races, religions and economic backgrounds equally.

The condition is caused by the presence of an extra copy of chromosome 21 in a baby's cells. It occurs by chance at conception and is irreversible. As yet, no one knows what causes the presence of the extra chromosome 21. 

Although the chance of having a baby with Down's syndrome increases with age, babies with the syndrome are born to mothers of all ages. There is no evidence that anything done before or during pregnancy causes the syndrome.

Read more about the causes of Down's syndrome.

Living with Down's syndrome

Some families find it difficult to accept a diagnosis of Down's syndrome and it is not uncommon for parents to experience negative thoughts after the birth of their new baby.

As with most new parents, a relationship begins to develop as their baby becomes more responsive and engaging. It is important to remember that a baby with Down's syndrome has the same needs as any baby. Books, magazines and support from family and friends are just as relevant.

Read more information for new parents on the Down's Syndrome Association's website.

Although there is no "cure" for Down's syndrome, there are ways to help children with the condition develop into healthy and fulfilled individuals who are able to achieve a level of independence right for them. This includes:

  • access to good healthcare, including a range of different specialists
  • early intervention programmes to provide support for children and parents
  • good parenting skills and an ordinary family life
  • education and support groups to provide information and help for parents, friends and families

Improved education and support has presented more opportunities to people with Down's syndrome. These include the option to leave home, form new relationships, gain employment and lead independent lives.

However, it is important to remember that each child is different and it is not possible to predict how individuals will develop.

Read more about treating Down's syndrome.


Many children with Down's syndrome have associated health conditions. Possible complications include:

  • heart disorders
  • bowel abnormalities
  • digestive problems
  • hearing and vision impairments
  • thyroid dysfunctions
  • infections
  • cervical spine dislocation
  • blood disorders

These conditions vary in severity with each individual. Some children experience none of them, while others experience several.

Your child may be checked by a paediatrician more often than other children to pick up developing problems as early as possible. If you have any concerns about your child's health, discuss them with your GP, health visitor or paediatrician.

Read more about the complications of Down's syndrome.

Down's syndrome: Emily's story

Emily was born with Down's syndrome. Watch her mum talk about the health issues they faced when she was little, and Emily's life as a young adult.

Media last reviewed: 12/11/2014

Next review due: 12/11/2016

Down's Syndrome Association (DSA)

If you would like more information about Down's syndrome, you can visit the DSA website or call their helpline on 0333 121 2300.

Carers: how to get practical support

Advice for carers with home care, care homes, equipment and more to help you with caring

Page last reviewed: 24/01/2013

Next review due: 24/01/2015