Patau Syndrome (Trisomy 13)

Patau Syndrome, also known as Trisomy 13, is a serious chromosomal disorder where an individual has an extra copy of chromosome 13 in their cells. This genetic condition leads to severe developmental abnormalities, affecting multiple organs. It is a rare condition, occurring in about 1 in 10,000 to 16,000 live births. Sadly, most affected infants do not survive beyond their first year due to the severity of associated complications.

What Causes Patau Syndrome?

Trisomy 13 is caused by an extra chromosome 13 in some or all of a person’s cells. Normally, a person has 46 chromosomes (23 pairs), but in Patau Syndrome, there are 47 chromosomes due to a full or partial extra chromosome 13. This genetic abnormality disrupts normal fetal development.

There are three main types of Trisomy 13:

1. Full Trisomy 13 – Every cell in the body has an extra copy of chromosome 13. This is the most severe and common form.
2. Mosaic Trisomy 13 – Some cells have the extra chromosome, while others have the normal 46 chromosomes. Symptoms may be milder compared to full Trisomy 13.
3. Partial Trisomy 13 – Only part of chromosome 13 is extra due to a translocation. This is the rarest form and can cause variable symptoms.

Risk Factors for Patau Syndrome

Although Trisomy 13 is a random genetic error, some factors increase the risk, such as:

• Advanced maternal age – Women over 35 have a higher risk of having a baby with chromosomal abnormalities.
• Genetic inheritance – In rare cases, Patau Syndrome is inherited due to chromosomal translocations in parents.

Patau Syndrome symptoms

Babies with Trisomy 13 exhibit multiple birth defects affecting nearly every organ. Common signs and symptoms include:

Physical Features:

• Microcephaly (small head size)
• Cleft lip and cleft palate
• Small or missing eyes (microphthalmia or anophthalmia)
• Low-set ears
• Polydactyly (extra fingers or toes)
• Small, underdeveloped jaw (micrognathia)
• Scalp defects (cutis aplasia)

Neurological Abnormalities:

• Severe intellectual disability
• Seizures
• Poor muscle tone (hypotonia)
• Structural brain defects, including holoprosencephaly (failure of the brain to divide properly)

Internal Organ Defects:

• Congenital heart defects (e.g., ventricular septal defect, atrial septal defect, patent ductus arteriosus)
• Kidney abnormalities
• Umbilical or inguinal hernias
• Gastrointestinal defects (e.g., omphalocele, where intestines protrude outside the abdomen)

Other Complications:

• Difficulty feeding
• Breathing difficulties (apnea episodes)
• Severe growth retardation

Diagnosis of Patau Syndrome

Trisomy 13 can be diagnosed before birth (prenatally) or after birth (postnatally).

Prenatal Diagnosis

Doctors use screening tests and diagnostic tests to detect Patau Syndrome before birth.

Screening Tests:

• Ultrasound – Detects physical abnormalities such as microcephaly, heart defects, or polydactyly.
• Non-invasive prenatal testing (NIPT) – A blood test that analyzes fetal DNA in the mother’s bloodstream to detect chromosomal abnormalities.

Diagnostic Tests:

• Chorionic Villus Sampling (CVS) – Performed at 10-13 weeks of pregnancy, this test analyzes placental cells for chromosomal abnormalities.
• Amniocentesis – Performed at 15-20 weeks, this test examines amniotic fluid for extra chromosome 13.

Postnatal Diagnosis

After birth, doctors diagnose Trisomy 13 based on physical examination and genetic testing (karyotyping).

Patau Syndrome treatment and management

There is no cure for Patau Syndrome, and treatment focuses on managing symptoms and improving the quality of life for the baby.

Medical Supportive Care:

• Feeding Assistance – Babies with cleft palate or poor muscle tone may need feeding tubes.
• Breathing Support – Respiratory issues may require oxygen therapy or ventilators.
• Heart Surgery – Some infants may need surgery for severe congenital heart defects.

Palliative Care:

Since most babies with Patau Syndrome have a very short life expectancy, palliative care focuses on comfort and symptom relief, ensuring the baby is as comfortable as possible.

Life Expectancy of Babies with Patau Syndrome

Unfortunately, Patau Syndrome has a very low survival rate.

• About 90% of babies die within the first year due to severe birth defects.
• Some babies survive beyond infancy, but they experience profound disabilities and require lifelong medical care.

Coping and Support for Families

Receiving a diagnosis of Patau Syndrome can be overwhelming for families. Support groups, genetic counseling, and palliative care teams can help families navigate this difficult journey.

Resources for Support:

• Support Organizations: Trisomy 13 Foundation, SOFT (Support Organization for Trisomy 13 & 18)
• Genetic Counseling: Helps families understand recurrence risks in future pregnancies.

Can Patau Syndrome be prevented?

There is no way to prevent Patau Syndrome, but couples with a history of genetic disorders may benefit from genetic counseling and prenatal testing before planning a pregnancy.

Patau Syndrome is a devastating genetic disorder with severe congenital abnormalities. While most affected infants do not survive long, supportive care can help families provide comfort for their child. Research continues to improve our understanding of genetic conditions, offering hope for better medical management in the future.

To consult a Pediatrician at Sparsh Diagnostic Centre, call our helpline number 9830117733.

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Disclaimer:

No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician.