Trisomy 13 or Patau Syndrome is a genetic abnormality in which a person is born with an extra copy of chromosome 13. This condition, which rarely occurs, mimics Edwards Syndrome. However, individuals with an excess chromosome 13 often suffer from a severe form of mental retardation. Brain and heart defects are also common among people who have Trisomy 13.
Babies born with Patau Syndrome have poor chances of survival. It is easily diagnosed at birth and further tests are performed to confirm the presence of heart and brain defects. Still, there are steps that can be done to help those who are afflicted and their families manage the syndrome. The treatment is generally aimed towards addressing the problems associated with the condition like speech problems and mental retardation.
Patau Syndrome causes
This form of genetic disorder occurs when an individual has 3 copies of chromosome 13 instead of just 2. The extra chromosome disrupts normal growth and development. The excess copy of chromosome 13 is attributed to the failure of the chromosome to split properly when multiplying. The error may have occurred when the sperm or egg cell is still forming or during fertilization.
Trisomy 13 is categorized into two, namely mosaic and complete. Mosaic Trisomy 13 occurs when a spare copy of chromosome 13 is found in some cells. On the other hand, it is termed as complete trisomy 13 when the extra chromosome is found in all body cells. Around 5% of trisomy 13 is ascribed as mosaicism, while 20% occur due to genetic translocation.
Who can be affected by Patau Syndrome?
Trisomy 13 can occur in both genders and affects 1 child in 10,000 live births. Studies showed that those with a family history of trisomy 13 have greater chances of conceiving a child with the same syndrome. There is an increased risk of trisomy 13 among women who are 35 years old or older.
Though the syndrome is relatively rare, but it definitely is the most severe form of trisomy as those affected don’t live to adulthood. Around 85% of the patients live less than a year and 44% have a life expectancy of 1 month. Only a few live up to 10 years, and fewer still reach 21 years.
The high mortality rate among trisomy 13 sufferers is often due to medical complications associated with the syndrome. Children born with the disorder often have heart defects as well as breathing and feeding problems. They also suffer from frequent bouts of seizures and have problems with hearing and vision. Moreover, congenital heart defect often leads to heart failure.
Patau Syndrome Symptoms
The symptoms of Patau syndrome significantly varies in each patient. However, congenital heart defects and severe mental retardation are among the major markers of the condition. Patients also have feeding problems and frequent episode of seizures.
Trisomy 13 is already evident at birth with the following features:
- Deformed feet
- Extra toes or fingers
- Small and sloping forehead
- Small eyes
- Abnormal ears
- Deformed or absent nose
- Cleft lip/palate
- Kidney defects
Trisomy 13 has a poor prognosis with most patients surviving only 3 days. A number live up to 6 months and a rare few reach adolescence. A significant number die before birth either due to still birth or miscarriage. Patients often expire due to cardiac arrest, pneumonia and congenital heart disease.
Though it may have a poor prognosis, but parents of children with Trisonomy 13 should still seek medical advice in order to receive counseling regarding their chances of having another Trisomy 13 child.
What does Patau Syndrome diagnosis involve?
Trisomy 13 is diagnosed immediately at birth based on the physical features of the child. It can even be confirmed before birth by subjecting the cells in the placenta or amniotic fluid to chromosome analysis. Ultrasound may be used but it is not as accurate as chromosome analysis. Even so, the doctor may still opt for further diagnostic tests to determine any anomalies in the patient’s internal organs. Imaging tests like Magnetic Resonance Imaging (MRI) or Computerized Tomography (CT scan) might be done to reveal renal and heart anomalies, as well as brain defects like fused cerebral hemispheres. On the other hand, ultrasound and gastrointestinal X-ray might be done to show abnormalities in the patient’s internal organs.
Patau Syndrome Treatment
Trisomy 13 has no cure and there is no way to prevent it either. Doctors generally plan the treatment based on the condition of the patient. The objective of the treatment is to help the patient and family manage the condition and accompanying physical problems.
Treatment for Patau Syndrome may involve the following:
- Speech therapy
Speech therapy helps in improving one’s ability to speak.
- Physical and occupational therapy
Physical and occupation therapists help the patient manage the associated mobility issues and maximize the patient’s developmental potential.
- Special education
Specialized education is needed to fill the educational needs of the child.
Surgery is often required to address cleft lip/palate or heart defects. But this is often withheld during the first year of the child’s life due to high rate of mortality.
Patau Syndrome Pictures