Trisomy 13
Patau's syndromehappens by chance and isn't caused by anything the parents have done.
Most cases of the syndrome don't run in families (they're not inherited). They occur randomly during conception, when the sperm and egg combine and the foetus starts to develop.
An error occurs when the cells divide, resulting in an additional copy or part of a copyof chromosome 13, whichseverely affects the baby's development in the womb.
In many cases, the baby dies before reaching full term (miscarriage) or is dead at birth (stillbirth) .
In most cases of Patau's syndrome (75-90%), a baby has a whole extra copy of chromosome number 13 in their body's cells. This is sometimes known as trisomy 13 or simple trisomy 13.
In 5-10% of cases of Patau's syndrome, genetic material is rearranged between chromosome 13 and another chromosome. This is called a chromosomal translocation.
Patau's syndrome that arises because of this can be inherited. Genetic Alliance UK has more information about chromosome disorders .
In a further 5% of cases, only some cells have the extra copy of chromosome 13. This is known as trisomy 13 mosaicism. Occasionally, only part of one chromosome 13 is extra (partial trisomy 13).
The symptoms and features of both mosaicism and partial trisomy tend to be less severe than in simple trisomy 13, resulting in more babies living longer.
Find out about Patau's syndrome, also known as trisomy 13, which is a serious genetic disorder where a baby has an extra copy of chromosome 13.
Babies with Patau's syndrome can have a wide range of health problems. Their growth in the womb is often restricted, resulting in a low birth weight, and 80% will be born with severe heart defects.
Patau's syndromehappens by chance and isn't caused by anything the parents have done. Most cases of the syndrome don't run in families (they're not inherited). They occur randomly during conception,
You'll be offered a screening test for Patau's syndrome as well as Down's syndrome (trisomy 21) and Edwards' syndrome (trisomy 18) from 10-14 weeks of pregnancy. The test assesses your chances of ha
Both parents will need to have their chromosomes analysed if their baby is affected by Patau's syndrome caused by a chromosomal translocation. Genetic testing is carried out to help parents plan for