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.
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.
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.
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.