Trisomy 13 or Patau syndrome is a genetic disorder in babies with three copies of the genetic material in the thirteenth chromosome. While healthy babies have two copies of genetic material in the thirteenth chromosome. The issue can affect the development of the baby in many ways. Keep reading to learn more about factors that may affect life expectancy in this condition.

Trisomy 13 Life Expectancy

While the condition is quite rare, you can still find babies born with it. The disorder can lead to serious mental and physical abnormalities including heart defects. Many babies with Patau syndrome are stillborn or die within the first few days after being born. It is hard to predict the life expectancy if the baby does not have any immediate life-threatening problems.

• About 50% of babies die within the first week of their birth.
• 90% die within a year.
• Only 5-10 % manage to live longer than a year.

Is There Any Treatment for Trisomy 13?

Unfortunately, there is no standard treatment available for babies born with this disorder. It is therefore difficult to improve Trisomy 13 life expectancy. Healthcare providers focus their treatment on improving symptoms only. Many children with this disorder eventually need surgery as well as occupational therapy, speech therapy, physical therapy, and other supportive treatment measures.

Some infants born with incurable birth defects, but some respond well to treatment used to correct structural abnormalities. Special formulas, techniques, and positions are used to deal with feeding problems. The placement of a gastric tube may help in this regard. Surgery is the only treatment option to correct structural abnormalities such as cleft palate and cleft lip. The combination of hearing aids, special diets, and vision aids may help deal with other symptoms of Patau syndrome.

Causes and Symptoms of Trisomy 13

Causes

While Trisomy 13 is a genetic disorder, it does not pass from the parents to the child. It mainly happens due to defects in the sperm or the egg that forms the fetus. Under normal circumstances, egg and sperm unite and form 23 pairs of chromosomes. In rare cases, egg and sperm form an extra chromosome and the chromosome 13 is released to the embryo. Both mother's egg cell and father's sperm cell can give that extra chromosome to the embryo.

There are three types of this disorder, and these types also have some impact on the overall Trisomy 13 life expectancy.

• Full Trisomy: In this condition, every cell in the body of an affected baby has an additional copy of chromosome 13.
• Partial Trisomy: In this condition, patients do not have a full extra copy of chromosome 13, and only an extra part of the chromosome attached to some other chromosome in the cells.
• Mosaic: Patients with this type of disorder have an entire extra copy of chromosome 13, but they are not present in some of the body's cells.

Symptoms

The symptoms usually depend on the severity of the condition. In addition, the symptoms may be different when only some of the cells are affected–it means the type of Trisomy 13 will also have an impact on how severe the symptoms are.

The most common symptoms include cleft palate, close-set eyes, cleft lip, clenched hands, extra fingers, impaired muscle tone, low-set ears, hernia, skeletal deformities, impaired mental development, and seizure. Some patients may also have a small lower jaw, small head, and un-descended testicles.

How Is Trisomy 13 Diagnosed?

A physical exam is usually all that is required to diagnose Trisomy 13. An affected baby will have certain physical characteristics and symptoms as mentioned already, which makes it easy for doctor to diagnose. Still, they may order a blood test to analyze the chromosomes to confirm the presence of chromosome 13.

It is also possible to analyze cells in the amniotic fluid to confirm the presence of chromosomal abnormalities. The fluid is usually obtained from the placenta through chorionic villus sampling (CVS). A detailed fetal ultrasound may also help make a diagnosis, but it is not a very reliable way. A chromosome analysis is usually 99.9% accurate.

How Often Does Trisomy 13 Occur?

It is quite a rare disorder and affects only 1 in 16,000 newborns in the US. The risk of having a baby with this disorder increases with the age of mother, but a woman can give birth to a baby with Trisomy 13 at any age.