Down's syndrome

by Claire Laurent

Down's syndrome | help and info

Down's syndrome is the most common form of learning disability, affecting about 1 in 1,000 babies. It is not a disease, although children with it may have greater health needs than other children. Most cases of Down's syndrome happen by chance, although around one per cent are due to a particular kind that's hereditary.

how it happens

image to accompany feature
© SPL

Chromosomes carry the blueprint for the characteristics we inherit. Each of our cells contains 23 pairs of them – 46 in all. But babies with Down's syndrome have an extra copy of chromosome 21 – a total of 47. About one per cent of people with Down's syndrome will have 'mosaic' Down's syndrome, where only some of the body's cells are affected.

antenatal screening

The chances of having a baby with Down's syndrome increases with a woman's age although paradoxically more babies with Down's syndrome are born to women under 30. This is probably because most pregnancies are in this age range and older women are more likely to have diagnostic tests for the condition.

However, it is usual for pregnant women, whatever their age, to be offered a test to assess their chance of having a baby with Down's syndrome. You do not have to take the test if you don't wish to and you might like to discuss what it means with the midwife. There are a range of possible tests depending on where you live, but not all are available on the NHS.

Alpha-Fetoprotein (AFP) test. A blood test offered in most areas. It is carried out at 16-18 weeks of pregnancy.
Triple test is an extension of the AFP test and is more effective at detecting Down's syndrome.
Triple plus test which claims to detect 85% of babies with Down's syndrome.
Ultrasound scan: a scan at around 18-20 weeks can pick up heart defects and other markers which are more common in babies with Down's syndrome.
Nuchal fold scan. A test which measures the fluid-filled space at the back of the baby's neck at 10-14 weeks of pregnancy.

For more on screening tests, check out the websites in help and info.

diagnostic tests

If you are found to be at greater risk through one of these tests you will be offered a diagnostic test. Both carry a small risk of miscarriage of about 1-2%.

Amniocentesis: a needle is inserted through the mother's abdomen into the amniotic sac to take a fluid sample.
Chorionic villus sampling: a sample is taken from the mother's placenta either through the abdomen or through the vagina.

If a positive diagnostic test is obtained some parents will decide to continue with their pregnancy, accepting the joys and challenges of bringing up a child with Down's syndrome as part of their family.

Some parents want to continue with the pregnancy, but don't feel they can take on the challenge for whatever reasons and want to give their child up for adoption.

Others, following confirmation that their unborn baby has Down's syndrome, will decide to terminate the pregnancy. By this time a woman will generally be at least 20 weeks pregnant and the procedure can be traumatic.

ARC (Antenatal Results and Choices) can help parents to come to a decision they are comfortable with. See help and info.

For more on diagnostic tests check out the websites in help and info.

diagnosis

Down's syndrome is usually diagnosed soon after birth, often because of the baby's appearance. There are many distinctive physical signs that may be apparent. These include:

reduced muscle tone making the baby 'floppy'
a flat facial profile, flat nasal bridge, small nose
eyes that slant upwards and outwards, often with an extra fold of skin in the eyelid called the epicanthic fold
a small mouth giving the appearance of a slightly large tongue
broad hands with short fingers and a little finger that curves inwards. The palm may have just a single crease across it
a below-average birth weight and length at birth.

However, many of these features are found in the general population so a blood test called a karyotype is done to analyse the baby's chromosome make up.

how does Down's syndrome affect development?

Children with Down's syndrome will take longer to meet developmental milestones than other children but most will learn to walk, talk, feed themselves and be toilet trained.

Early intervention will help your child reach his or her full potential – physiotherapy and speech therapy are important early on.

People with Down's syndrome continue to learn throughout their lives, just like non-disabled people.

associated medical problems

There are some medical problems that are more common to people with Down's syndrome than the rest of the population. These include:

heart problems: 40-50% of people with Down's syndrome have heart problems, some of which require surgery
hearing and sight problems
thyroid problems
poor immune system
respiratory problems – coughs and colds
obstructed gastrointestinal tract.

Adults with Down's syndrome are more likely to develop diabetes than other people and may develop Alzheimer's earlier than the rest of the population.

However, many people with Down's syndrome don't experience any extra health problems.

the future

At one time the various health problems associated with Down's syndrome meant that people with the condition had a reduced life span. But now, advances in medical treatment mean that the life expectancy for people with Down's syndrome is 60-65 years and many live longer. People with Down's syndrome are more integrated into the community than they once were but most will need support throughout their lives.

This can put a great strain on older parents and on brothers and sisters. A survey by MENCAP called No Ordinary Life, found that parents of people with profound and multiple learning disabilities are often exhausted by the round-the-clock care their offspring need and yet they receive very little outside help.

For information on financial benefits, day centres and respite care, contact your local social services department as well as one of the groups listed in help and info. See also our feature on learning disablities.

living with Down's syndrome

'Natalie was three hours old and I was on my own when I was told that she probably had Down's syndrome,' remembers Sue Baker. The hospital apologised later for being so insensitive and Sue says she received a lot of support in the early days. 'They didn't paint this wonderful picture of Down's syndrome but they did give me so much information I could work with ... The most important part for me was actually doing something.'

Sue and her husband Dennis have a son of 23 who does not have Down's. Sue was 38 when she had Natalie who is now nine years old. 'I didn't have any tests during pregnancy because I'd lost a baby boy before Natalie at seven months and I didn't want to take any chances.'

Natalie doesn't have any of the medical problems so often associated with Down's syndrome. She attends mainstream school and has many friends, some learning disabled but most are not.

'Her statement (see feature on special educational needs for more on statementing) said that she should attend mainstream school but after a year in the nursery of the school we wanted her to go to they said she would do better in a special school,' says Sue. Sue remembers sobbing in the car all the way home. 'It's that rejection of your child that's so hard for a parent. It takes years to get above that.'

Sue and Dennis won an appeal against the decision and Natalie has remained in mainstream school ever since although they have had to fight each year to keep her there. 'She's now in the juniors and achieving and there is every expectation that she will go on to secondary school. She has lots of friends, enjoys pop music and dancing and can swim.'

Sue's experience has encouraged her to campaign on behalf of other parents for mainstream schools for learning disabled children, and she has recently been elected as a councillor for the Royal Borough of Kingston.

(February 2003, resources updated June 2005)

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