Trisomy 13 (also known as Patau syndrome)
Trisomy 13, also called Patau syndrome, is a severe chromosomal condition, with multiple malformations due to an additional copy of all or part of chromosome 13. The cause is unknown. Babies are usually identified at birth due to several recognizable physical features but the diagnosis is confirmed with genetic testing. Individuals with trisomy 13 often have heart defects, brain, or spinal cord abnormalities. Babies are often small at birth and have characteristic facial appearance along with poor muscle tone. Some of these features include: small head size (microcephaly), small eyes (microphthalmia), cleft lip/palate, and variations in ear shape.
Trisomy 13 occurs in 1 of 10,000-16,000 births and the incidence increases with increased maternal age. The risk of recurrence in future pregnancies is 1%. Most cases are not inherited and result from random formation of eggs and sperm in healthy parents.
Common Associated Conditions
Babies with trisomy 13 will have a characteristic group of problems that may include the following: microcephaly (small head size), cleft lip and/or cleft palate (facial and/or oral defect), omphalocele (abdominal defect), spina bifida (open spine defect), microphthalmia (small eyes), anophthalmia (absent eyes), scalp defects, polydactyly (extra fingers and toes), cryptorchidism (undescended testes), omphalocele (infant’s intestines, liver or other organs stick outside of the belly), holoprosencephaly (anatomic defect of the brain involving the forebrain), kidney defects, and skin defects of the scalp. About 80% of infants with Trisomy 13 will have a heart defect as well. The type of heart defect varies, but most would be a ventricular septal defect (opening between the lower heart chambers), an atrial septal defect (opening between the upper chambers), a patent ductus arteriosis (a blood vessel from fetal life that does not close), or dextrocardia, which is a location of the heart on the right side of the chest instead of the left side.
Short-term Treatment and Outcomes
Parents of a baby with Trisomy 13 face many difficult decisions regarding the care of their child. Babies will be given comfort care, and 80% will not survive past the first month of life. Most will not live past the first week, regardless of medical intervention. Despite good caloric intake, many babies with chromosomal defects will show slow growth. Parents will be offered genetic testing and counseling.
A very few children are less severely affected and will overcome many of the difficulties; those babies should receive regular child care visits for immunizations and anticipatory guidance, with screening at frequent intervals for vision and hearing difficulties, scoliosis, developmental delays and symptoms of other conditions that can be treated.
Long-term Treatment and Outcomes
Virtually all of the 5% of children who survive past the first year will exhibit developmental and growth delays. Early intervention programs and special education will be very important to the relatively small number of children with trisomy 13 who survive the difficult early months.
The list of possible complications is very great because so many body systems are affected with the trisomy 13 condition. Infection and difficulty feeding will be big issues in caring for these babies.
Implications for Children's Development
The birth of a medically fragile child is difficult and families will find support from other families who have experienced similar circumstances. Parents often learn from other parents how to be the advocates for their child’s needs. Support groups can be found on the internet as well as in many communities for many of the day-to-day caretaking challenges of parents. Decision-making for children with chromosomal defects is difficult and complex and parents need information and support from their medical providers and community. Listed below are organizations that provide practical information and support for families with a child with trisomy 18.
- Genetics Home Reference: Trisomy 13
- Support Organization for Trisomy 18, 13, and Related Disorders (SOFT)
- Hope for Trisomy 13 & 18 - Not-for-profit organization
- Trisomy Conditions
- Prenatal Booklet
- Prenatal testing
- Prenatal Trisomy Diagnosis Awareness Act
- Prenatal Trisomy Diagnosis Awareness Act Fact Sheet (PDF)