Patau Syndrome - Trisomy 13

What is Patau Syndrome?

Patau syndrome, also known as Trisomy 13, is a rare genetic disorder caused by the presence of an extra copy of chromosome 13. This genetic change leads to a variety of physical and cognitive abnormalities that are typical of the disorder. 

What is the cause of Patau Syndrome?

Patau Syndrome is caused by the presence of an extra copy of chromosome 13 in the cells of the body. Normally, each cell in the human body contains 23 pairs of chromosomes, for a total of 46 chromosomes. One of each pair of chromosomes is inherited from each parent.

In individuals with Patau Syndrome, there are three copies of chromosome 13 instead of the usual two. This can occur when an error in cell division during fetal development leads to an extra copy of chromosome 13 in some or all of the cells of the body.

The majority of cases of Patau Syndrome occur sporadically, meaning that they are not inherited from either parent. However, in some cases, Patau Syndrome can be inherited from a parent who carries a rearrangement of chromosome 13, or a translocation, which can increase the risk of having a child with Patau Syndrome.

It's important to note that the cause of the chromosomal error that leads to Patau Syndrome is not well understood, and there is no known way to prevent the condition from occurring. 

Features of Patau Syndrome

The most common features of Patau syndrome include:

Physical Abnormalities: 

Children with Patau syndrome may have:

• Small head (microcephaly), a small jaw, and a small face

• An abnormally small eye or eyes (microphthalmia)

• Absence of an eye or both of the eyes (anophthalmos)

• reduced distance between the eyes (hypotelorism)

• problems with the development of the nasal passages

• They may also have cleft lip and palate, 

•  Webbed fingers and toes, 

• Extra fingers or toes (polydactyly).

Health Problems: 

Children with Patau syndrome are at higher risk for certain health problems such as:

Heart Defects:

Patau Syndrome is often associated with heart defects, which can be life-threatening and require surgery. The common types of heart defects seen with Patau syndrome are:

1.) Ventricular septal defect (VSD): This is a type of congenital heart defect in which there is a hole in the wall that separates the two lower chambers (ventricles) of the heart. This can cause oxygen-rich and oxygen-poor blood to mix, which can strain the heart and lungs.

2.) Atrial septal defect (ASD): This is a type of congenital heart defect in which there is a hole in the wall that separates the two upper chambers (atria) of the heart. This can cause oxygen-rich and oxygen-poor blood to mix, which can strain the heart and lungs.

3.) Dextrocardia: This is a condition in which the heart is located on the right side of the chest instead of the left side. This can occur on its own or as part of another condition.

4.) Patent ductus arteriosus (PDA): This is a condition in which a blood vessel called the ductus arteriosus, which connects the pulmonary artery to the aorta in a developing fetus, fails to close after birth. This can cause oxygen-rich and oxygen-poor blood to mix, which can strain the heart and lungs.

5.) Transposition of the great arteries: This is a condition in which the two main blood vessels leaving the heart, the pulmonary artery and the aorta, are switched.

6.) Coarctation of the aorta: This is a narrowing of the aorta, the main blood vessel that carries oxygen-rich blood from the heart to the body.

Breathing problems: 

Infants with Patau Syndrome may experience breathing difficulties due to abnormalities in the structure of the airway or lungs.

Vision and hearing problems: 

Patau Syndrome can cause vision and hearing problems, including cataracts, strabismus, and hearing loss.

Seizures: 

Individuals with Patau Syndrome may experience seizures due to abnormal brain development.

Feeding difficulties: 

Infants with Patau Syndrome may have difficulty feeding due to oral abnormalities, weak suck reflexes, and swallowing difficulties.

Growth and developmental delays: 

Children with Patau Syndrome may experience delays in growth and development, including delayed motor skills, language development, and cognitive skills.

It's important to note that the specific complications and health effects of Patau Syndrome can vary widely between individuals, and may be influenced by factors such as the severity and type of physical abnormalities present, the presence of associated health problems and complications, and the individual's response to treatment.

Unfortunately, Patau syndrome is one of the most lethal chromosomal disorders, with 50% of newborns passing away in the first week of life, and the rest of the children dying within the first year of life. 

Diagnosis of Patau Syndrome

Patau Syndrome, also known as trisomy 13, can be diagnosed through prenatal screening and diagnostic tests, as well as after birth through physical examination and genetic testing.

Prenatal screening tests for Patau Syndrome may include:

Noninvasive prenatal screening (NIPS): 

This blood test is performed on the mother and can detect the presence of chromosomal abnormalities, including trisomy 13.

Maternal serum screening (MSS): 

This blood test is also performed on the mother and measures levels of certain hormones and proteins that can indicate a higher risk of chromosomal abnormalities.

Ultrasound: 

This imaging test can detect physical abnormalities that are associated with Patau Syndrome, such as brain defects, heart defects, and cleft lip and/or palate.

If prenatal screening tests indicate a higher risk of Patau Syndrome, diagnostic tests such as chorionic villus sampling (CVS) or amniocentesis may be recommended to confirm the diagnosis. These tests involve sampling cells from the placenta or amniotic fluid to analyze the fetal chromosomes.

After birth, a healthcare provider may suspect Patau Syndrome based on physical features such as cleft lip and/or palate, extra fingers or toes, and heart or brain abnormalities. Genetic testing can confirm the diagnosis by analyzing the baby's chromosomes. In some cases, Patau Syndrome may not be diagnosed until later in life due to mild or atypical symptoms.

Management for Patau Syndrome

The management of Patau Syndrome focuses on providing supportive care to manage the various health problems and complications associated with the condition.

Treatment options for Patau Syndrome may include:

Medical management 

Depending on the specific health problems and complications present, medical management may include medications to control seizures, antibiotics to prevent or treat infections, and surgery to correct certain physical abnormalities.

Feeding support 

Infants with Patau Syndrome may experience difficulties with feeding due to cleft lip and palate, low muscle tone, and other physical abnormalities. Feeding support may include specialized feeding techniques, tube feeding, or surgery to repair cleft lip and palate.

Early intervention services

Early intervention services, such as physical therapy, occupational therapy, and speech therapy, can help infants and children with Patau Syndrome reach their full developmental potential and improve their quality of life.

Palliative care 

In cases where the health problems and complications associated with Patau Syndrome are severe or life-limiting, palliative care may be recommended to manage symptoms and improve quality of life. This may include pain and symptom management, emotional support, and assistance with end-of-life care.

It's important to note that the management of Patau Syndrome is highly individualized and will depend on the specific health problems and complications present in each affected individual. A healthcare provider can provide more information on the available treatment options and help develop a personalized care plan based on the individual's needs and circumstances.

Prognosis of Patau Syndrome

The prognosis for Patau Syndrome, also known as trisomy 13, is generally poor. Many infants with Patau Syndrome die in utero or shortly after birth, and those who survive may have severe physical and intellectual disabilities.

The specific outlook for an individual with Patau Syndrome will depend on a variety of factors, including the severity and type of physical abnormalities present, the presence of associated health problems and complications, and the individual's response to treatment.

Infants with Patau Syndrome may experience a range of health problems and complications, including heart defects, kidney problems, brain abnormalities, and breathing difficulties, among others. These health problems can significantly impact the infant's health and quality of life and may lead to early death.

However, with advances in medical care and supportive treatments, some individuals with Patau Syndrome are living longer and experiencing a better quality of life than in the past. Early intervention services, such as physical therapy, occupational therapy, and speech therapy, can also help improve the individual's developmental outcomes and quality of life.

It's important to note that the prognosis for Patau Syndrome is highly variable and can be difficult to predict.

Caregivers and family members may also need support and care.

It is important for couples who may be at risk of having another child with Patau syndrome to receive genetic counseling. This counseling can provide emotional support and present options for the couple to consider.