Patau syndrome

Patau Syndrome (Patau syndrome)

1) Disease Description (Causes and Symptoms)

• Cause: Trisomy 13 is the main cause. Most cases are full (typical) trisomy (approximately 75%), while approximately 25% are caused by Robertsonian translocation (the risk of recurrence increases if a parent is a carrier). The typical form is associated with maternal age.

• Pathophysiology: Overexpression of genes due to an extra copy of chromosome 13 affects various processes in fetal development (particularly midline, facial, cardiac, and renal development), resulting in severe malformations and functional impairment. Central nervous system abnormalities such as holoprosencephaly are common.

• Major symptoms (representative)

  • Microcephaly, microphthalmia, holoprosencephaly (midline structural abnormalities)
  • Cleft lip and cleft palate, facial malformations
  • Polydactyly (multiple fingers or toes), micrognathia
  • Congenital heart defects (ventricular or atrial septal defects, patent ductus arteriosus, etc.)
  • Renal malformations (such as polycystic kidneys), undescended testes
  • Severe developmental delay and profound intellectual disability
  • High mortality in infancy (approximately 1 in 20,000 live births; more than 80% die within 1 month after birth, and some [approximately 3%] survive to 6 months)

• Diagnosis: A definitive diagnosis is made through clinical findings plus chromosome testing (standard karyotyping). Prenatal screening (NIPT) and amniocentesis/chorionic villus sampling for confirmation, and chromosomal microarray analysis (CMA) when necessary, may be used.

2) Treatment Methods and Precautions

• Basic treatment approach: Multidisciplinary, symptomatic management according to the symptoms (there is no curative treatment). Collaboration among pediatric surgery, cardiac surgery, neurology, orthopedics, genetic counseling, rehabilitation, and nutrition teams is necessary.
• Major treatments/management
  • Respiratory and nutritional support: Prevention of aspiration, parenteral nutritional support, and PEG placement when necessary
  • Treatment of heart disease: Conservative treatment or surgical correction of cardiac defects (determined according to the child's condition, prognosis, and the parents' wishes)
  • Corrective surgery for cleft lip and palate and surgery to correct digital malformations (for functional and hygiene purposes)
  • Seizure management: Use of anticonvulsants (when seizures occur)
  • Active treatment of infections and respiratory problems
  • Rehabilitation: Physical, speech, and occupational therapy (to maintain function and prevent complications)
  • Hospice and palliative care: When the prognosis is poor, a treatment plan focused on symptom relief and quality of life is necessary
• Medications: Anticonvulsants, heart failure medications (when necessary), antibiotics, and others are used according to the symptoms.
• Precautions
  • Fully discuss the risks and expected benefits of each procedure and surgery with the family (considering survival prospects, complications, and quality of life).
  • High-risk group during anesthesia and surgery (airway problems and congenital heart disease) — evaluation by a specialist team
  • Genetic counseling is recommended for the parents: Parental chromosome testing is important to determine whether a parent is a carrier of a Robertsonian translocation (to assess the risk of recurrence).
  • Pay attention to vaccinations, infection control, and nutritional status.

3) Outpatient Visit Checkpoints (Examples of Items to Bring and Records)

• Items and documents to bring
  • List of current medications (dosage and administration times)
  • Previous test results: chromosome testing (karyotyping), prenatal test results (NIPT/amniocentesis/chorionic villus sampling), and reports from imaging tests such as echocardiography, cranial ultrasonography, and abdominal ultrasonography
  • Birth records, surgical records, and hospitalization records (if available)
  • Vaccination records
  • Family history (especially a history of malformations or genetic diseases in the parents or siblings)
• Symptom and progression records
  • Feeding volume, vomiting, and weight gain records (growth chart)
  • Notes on the date, time, and characteristics of breathing difficulty, cyanosis, fever, or seizures
  • Bowel movement and urination patterns; problems with urination or defecation
• Questions to prepare for the visit (examples)
  • How to respond to urgent symptoms or worsening symptoms
  • The schedule and necessity of future tests and surgery

4) Examples of General Questions to Ask the Doctor

• What are the expected effects and side effects of this treatment (medication/surgery)?
• What is your expectation of the child's long-term prognosis (survival prospects and functional prognosis)?
• What are the immediate treatment priorities and the long-term management plan?
• What should parents do to prevent infections and manage daily care?
• How can we arrange rehabilitation and educational (special education) services?

5) Examples of Disease-Specific Questions

• Do you recommend chromosome testing to determine whether either parent is a carrier of a Robertsonian translocation? How will you explain the risk of recurrence based on the test results?
• If a heart malformation is found, how do you evaluate the indications for surgical correction and the expected quality of life after surgery?

Additional notes: Diagnosis, treatment, and prognosis can vary greatly depending on the individual's condition (typical, mosaic, or translocation form; severity of associated malformations, etc.). It is important to determine treatment goals (aggressive treatment versus palliative treatment) together with the family through genetic counseling and consultation with a multidisciplinary team.