Babies with Patau’s syndrome have more of chromosome 13 in some or all of the cells in their body. It is also known as Trisomy 13.

In the UK, around two in every 10,000 births are affected by Patau’s syndrome.

Most cases result from a random change in the egg or sperm in healthy parents. This change is not caused by anything parents did before or during pregnancy.

About Patau’s syndrome

Patau’s syndrome affects approximately 2 in every 10,000 births in the UK.

Babies normally inherit 2 copies of each chromosome, 1 from their mother and 1 from their father, in each cell in their body.

A baby with Patau’s syndrome has 3 copies of chromosome 13 in each or some of their cells.

How your baby's affected

How your the baby's affected depends upon a number of things, including the form of Patau’s syndrome they have.

Most babies have delayed physical and learning development and a range of health conditions, some of which can be serious.

The risk of miscarriage in early pregnancy is high however, this risk decreases as the pregnancy progresses. There is also a risk of stillbirth.

The full form of Patau’s syndrome can also affect how long your baby can live.

Patau's syndrome can vary

There are different forms of Patau’s syndrome, these are known as full Patau’s syndrome and partial or mosaic forms.

Full form

Around 80% of babies born with Patau’s syndrome will be affected by the full form of the syndrome. This means the extra chromosome 13 is present in all of the baby's cells.

Mosaic form

The mosaic form means that the baby will have an additional chromosome 13 in some but not all of its cells. How the baby is affected will depend on the percentage of cells affected and where those cells are located in the body.

Partial form

The partial form of Patau’s syndrome is much rarer and means there is a partial additional chromosome 13 in the baby’s cells. In some cases, the partial copy may adhere to another chromosome. The partial form of the syndrome can be due to inherited factors.

Living with Patau's syndrome

Each child is unique, and Patau’s syndrome will affect each child differently.

Like all children they will have their own personalities, likes and dislikes and things that make them who they are.

Caring for a child with Patau's syndrome

There are challenges in caring for a baby with full Patau’s syndrome.

They may have some of the range of health conditions associated with the syndrome.

Many babies have difficulties feeding and may need to be fed via a tube.

Some babies experience seizures, have heart defects and have apnoea or pauses in their breathing.

They will also have some level of learning disability, which can be severe.

How children with mosaic or partial forms of Patau’s syndrome are affected is more varied and depends upon how many of their cells contain the extra chromosome and where those cells are located in their body.

Some children may have much less serious developmental and health issues.

Child development

Despite their complex needs, children with Patau’s syndrome can make progress with their development, although slowly.

Many children are reported to be able to communicate their needs, show awareness of surroundings and some can sit and stand supported.

Older children may attend school.

Feedback from parents suggests a positive quality of life for their child as a valued member of the family.

Because children with the mosaic or partial form of Patau’s syndrome have fewer cells carrying the additional chromosome, they may be much less severely affected or even have no observable effect.

However, it's not always the case as the impact can be extremely variable form one child to another. Unfortunately, it's not possible to predict this variance before the child is born.

Patau's syndrome and health

Babies born with full Patau’s syndrome are likely to have a wide range of health conditions, some of which can be serious:

  • Around 8 in 10 (80%) babies will have heart issues
  • Around 5 in 10 babies (50%) will have seizures
  • 5 in 10 (50%) may have hearing loss and joint contractures.
  • 6 in 10 (60%) may have cleft lip and/or palate
  • 6 in 10 (60% may have issues with brain development
  • 5 in 10 (50%) may have eye issues or an absent eye

They may also need medical help with swallowing, feeding and breathing.

These babies usually have a low birthweight and are considered medically fragile, often susceptible to respiratory and other infections and complications requiring hospital admission.

Patau’s syndrome and life expectancy

Around 7 in 10 (70%) pregnancies diagnosed with Patau’s syndrome at 12 weeks will end in miscarriage or stillbirth.

The risk of miscarriage is higher in early pregnancy and decreases as the pregnancy progresses.

The full form of Patau's syndrome is considered to be a life-limiting condition which means it affects how long the baby can live.

Around 4 in 10 (43.1%) may live longer than 1 week, 11.5% may live longer than 1 year and around 1 in 10 (9.7%) may live longer than 5 years.

The life expectancy for children with mosaic or partial forms of Patau’s syndrome is much more variable, from no impact at all to similar for children with full Patau’s syndrome.

Screening for Patau's syndrome

During your pregnancy you'll be offered a test to screen for Patau’s syndrome. It’s your choice whether to have the test.

Screening tests can tell you if your baby has a higher chance of having Patau’s syndrome.

A diagnostic test will be able to tell you if your baby definitely has the syndrome, but these tests carry a slight risk to your pregnancy.

Some physical signs of Patau’s syndrome may be seen during the mid-pregnancy screening scan (18-21 weeks of pregnancy).

However, screening tests, scans and diagnostic tests cannot tell you if your baby has the full, mosaic or partial form of Patau’s syndrome or how the baby may be affected.

Further information

You can find out more information about Patau's syndrome and the experiences of parents of a child with the syndrome at SOFT UK (Support Organisation for Trisomy 13/ 18)


Source: SOFT UK

Last updated:
14 June 2021