Getting to Know Patau or Trisomy 13, a Rare Syndrome That Babies Can Experience

Can cause severe mental and physical problems in children, can this rare trisomy 13 syndrome be prevented?

Ever heard of trisomy 13, Mom? This syndrome, caused by a chromosomal abnormality and known as Patau Syndrome, is quite rare, and is generally experienced by babies while still in the womb.

So, what causes it and how do you know if your baby has this disorder? Here is an explanation summarized from several trusted sources.

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What is Patau Syndrome?

trisomi 13

Patau syndrome or trisomy 13 is a genetic disorder that occurs when a baby gets an extra 13th chromosome in the womb.

Every human being should only have two copies of chromosome 13, but when the cells of this chromosome divide (the process of cell division) during reproduction, the cells divide abnormally and create extra genetic material on chromosome 13 – resulting in three copies of chromosome 13.

According to WebMD , this extra chromosome could come from an egg or sperm cell. Although any woman of any age can be at risk of having a baby with Patau Syndrome, the chances of having a child with this condition increase with age.

As some experts have stated, a mother is at higher risk of having a baby with chromosome 13 abnormalities if she becomes pregnant after the age of 35.

This extra 13th chromosome can cause serious mental and physical problems in the baby after he is born.

As explained on the Medline Plus page , the mental and physical problems caused by Patau Syndrome include severe intellectual disabilities and physical abnormalities in many parts of the body.

Babies with trisomy 13 often have problems such as heart defects, brain or spinal cord abnormalities, very small or underdeveloped eyes ( microphthalmia ), extra fingers or toes, a hole in the lip ( cleft lip ) with or without a hole in the roof of the mouth, problems with the mouth (cleft palate), and weak muscle tone (hypotonia).

Due to the many physical problems, most babies born with Patau Syndrome do not live past their first month or year.

Only 5 to 10 percent of babies with this condition live past their first year. However, some survive for many years.

How Common Is This?

Source: Freepik

Trisomy 13 occurs in about 1 in 16,000 newborns. As mentioned above, the likelihood of a mother having a baby with this condition is closely related to the mother’s age at pregnancy, which is over 35 years old.

Other scientific names for this condition are:

Bartholin-Patau syndrome

Complete trisomy 13 syndrome

Patau syndrome

Patau’s syndrome

Trisomy 13 syndrome

Causes of Patau Syndrome

Most cases of trisomy 13 result from having three copies of chromosome 13 in each cell in the baby’s body, instead of the normal two copies.

This extra genetic material interferes with normal development and causes the characteristic features of trisomy 13.

Trisomy 13 occurs when chromosome 13 attaches (translocates) to another chromosome during the formation of reproductive cells (eggs and sperm) or can also occur early in fetal development.

In rare cases, only part of chromosome 13 is present in three copies. The physical signs and symptoms of this case may differ from those found in full trisomy 13.

Some babies with trisomy 13 have an extra copy of chromosome 13 in only some of their body cells, called mosaic trisomy 13.

The severity of mosaic trisomy 13 depends on the type and number of cells that have the extra chromosome. It is often milder than full trisomy 13.

Diagnosis

Source: Freepik

The doctor will look for physical signs of trisomy 13 during a routine examination in the first trimester via fetal ultrasound (USG).

Or, usually if the mother is over 35 years old when she is pregnant, the doctor will suggest doing a test using cell-free deoxyribonucleic acid (DNA) from the mother’s blood sample.

This technique is called non-invasive prenatal testing (NIPT) and can be done from 10 weeks of pregnancy. Another test is Pregnancy-Associated Plasma Protein A ( PAPP-A) or pregnancy-related plasma protein A.

This test is only a screening test, which means it cannot confirm whether your baby has trisomy 13 or not.

To make a proper diagnosis, the doctor will recommend some more tests such as an amniocentesis test to check for chromosomal abnormalities in the baby.

One of them is chorionic villus sampling (CVS) or amniocentesis. However, this action is risky because of its invasive nature, where one of the risks is miscarriage .

Patau Syndrome Chromosome Formula

The chromosomes in Patau syndrome contain all the genetic material to help human cells divide and eventually grow into babies.

A healthy baby is born with 46 chromosomes, arranged in 23 pairs. A baby with Patau Syndrome, on the other hand, has an extra copy of chromosome 13 in every cell of his body.

There are several forms of trisomy 13:

Full trisomy 13: Full Patau syndrome is the most common and most severe form of the condition, in which every cell in the body has an extra chromosome 13.
Translocation trisomy 13 : an inherited form of the syndrome in which part of chromosome 13 is attached to another chromosome. This type accounts for about one in five cases of Patau Syndrome.
Mosaic trisomy 13 : a less severe and rare form of the syndrome, in which some cells have an extra chromosome 13, rather than every cell.
Partial trisomy 13 : another rare form of this condition, which occurs when part of an extra chromosome, rather than the whole thing, is present in the cell.

Around 150 babies with Patau Syndrome are born in the UK each year. Patau Syndrome causes serious complications and, sadly, most affected babies die during pregnancy.

Babies born with Patau syndrome usually survive for only a few days. In rare cases, some babies with a less severe form of the syndrome have lived for more than a year.

Although rare, babies with Patau Syndrome usually have severe physical and mental disabilities and serious health problems.

Symptoms of Patau Syndrome

Source: Freepik

Babies born with trisomy 13 often have low birth weight, even if they are not born prematurely .

Usually babies with this condition have problems with brain structure, and experience effects on facial development.

Babies with trisomy 13 may have eyes that are close together and an underdeveloped nose or nostrils, as well as a cleft lip or palate.

Other birth defects that a baby with Patau Syndrome is likely to experience include:

Clenched fists
Cleft lip or palate
Extra fingers or toes (polydactyly)
Hernia in babies
Kidney, wrist, or scalp problems
Low ear position
Small head ( microcephaly )
Undescended testicles

Babies born with trisomy 13 or Patau Syndrome can have many health problems, more than 80% of them do not survive more than a few weeks.

Even if some survive, the baby will generally experience serious complications, including:

Difficulty breathing
Congenital heart defects
Hearing disorders
High blood pressure (hypertension)
Intellectual disability
Neurological problems
Pneumonia
Febrile convulsion
Slow growth
Difficulty digesting food

Trisomy 13 Prevention and Treatment

Once the doctor’s diagnosis results come out (which state that the baby is positive for Patau Syndrome), there is no medication that can be given to the mother during pregnancy to treat trisomy 13 in the baby.

The treatment only focuses on the symptoms felt by the baby after birth, the aim is to reduce the symptoms.

The treatment in question includes surgery and therapy, depending on the severity of the condition.

Next, the doctor may choose to wait and consider any action based on the baby’s chances of survival.

However, mothers should not worry, because sometimes Patau Syndrome is not always fatal and life-threatening, although doctors cannot predict how long the baby will live.

However, babies born with trisomy 13 rarely live to adolescence.

Caring for Babies Diagnosed with Trisomy 13 in the Womb

One of the first questions you may be asked if your baby is diagnosed with trisomy 13 while in the womb is whether you want to continue the pregnancy or have intensive interventions if the baby is born with health problems.

During pregnancy, some parents choose to terminate a baby diagnosed with trisomy 13 because of the generally poor prognosis and the desire not to prolong the grief of loss.

Others choose to continue the pregnancy because of personal beliefs against abortion, or because they feel they would rather have time with their baby, even if it turns out to be a short time.

The same is true for babies diagnosed after birth — some parents simply opt for comfort care, while others choose intensive medical intervention, even though the baby is unlikely to survive.

A 2017 study suggested that performing congenital heart surgery on babies with trisomy 13 may improve their chances of survival.

However, there is still not enough research to support this claim, and study researchers still argue that the surgery carries high risks for babies who already have a low chance of survival.

The Importance of Genetic Testing for Parents

Genetic testing of parents is very important because it can determine whether there is a possibility of Patau syndrome again in the next pregnancy.

Both parents need to have their chromosomes analyzed if their baby has Patau syndrome which is caused by a chromosome translocation.

Genetic testing is done to help parents plan for future pregnancies, not as part of the decision-making process for a current pregnancy.

The test results will allow a more accurate assessment of the likelihood of the syndrome affecting future pregnancies. In addition to the parents, other family members may also be affected and should be tested.