We are continuing to observe National Developmental Disabilities Awareness Month by sharing the research from the NIDILRR community and sharing information and resources on developmental disabilities as a whole and on different types of developmental disabilities, such as Down syndrome. This week, we would like to share information and resources about two of the rarer forms of trisomy: Patau syndrome and Edward syndrome.
Patau syndrome is also known as Chromosome 13, Trisomy 13 complete, Complete Trisomy 13 syndrome, and D Trisomy syndrome. It is named after one of the researchers who identified its origin in 1960. It is a rare trisomy disorder where all or part of chromosome 13 appears three times, instead of twice, in cells in the body. According to the National Organization for Rare Disorders (NORD), the “range and severity of associated symptoms and findings may depend on the specific location of the duplicated portion” of chromosome 13 in individuals with Patau syndrome. Signs and symptoms associated with Patau syndrome may vary in range and severity in each person, but they often include craniofacial, neurologic, cardiac, and other defects that include developmental delays, cleft lip and/or palate, microcephaly, and renal malformations. Many babies with Patau syndrome fail to thrive and have diminished muscle tone, severe feeding issues, and times where they stop spontaneous breathing.
In most people with Patau syndrome, the cause of the duplication of chromosome 13 is spontaneous errors during the division of reproductive cells in one of the parents. The risk of these errors occurring increases with the age of the parents. In some people with Patau syndrome, the errors may also happen during the cellular division after the egg is fertilized. Patau syndrome also occurs due to a translocation involving chromosome 13 and another chromosome and only occurs in about 20% of people affected by Patau syndrome. It seems to affect more females than males and it occurs in about one in 5,000 to 12,000 live births, according to NORD. Research suggests that about one percent of all recognized miscarriages happen in association with Patau syndrome. Research also suggests that there is a possible connection between preeclampsia and Patau syndrome.
Most infants with this disorder do not live past their week of life and varies from child to child. Treatments for Patau syndrome deal with the specific symptoms for each person, are symptomatic and supportive, and may require a multidisciplinary team of healthcare professionals. Part of the multidisciplinary team may include social services and a genetic counselor for families of children with Patau syndrome.
Edward syndrome, or trisomy 18, is a very rare disorder that results from having three copies of chromosome 18 in each cell of the body. This extra genetic material interferes with the normal course of development. Edward syndrome occurs in about 1 in 5,000 live born infants. It is more common during pregnancy; however, many of the affected fetuses do not live to term. It is also three times more common in girls than in boys.
Babies with Edward syndrome may display some or all of the following signs and symptoms: clenched hands, feet with a rounded bottom, low birth weight, low set ears, cognitive delays, microcephaly, small jaw, an unusually shaped chest, issues in the development of the eyes, umbilical hernias, congenital heart issues, and kidney issues. There are no specific treatments for Edward syndrome. Instead, the treatments used are dependent on the baby’s individual condition. MedlinePlus states that genetic counseling “can help families understand the condition, the risks of inheriting it, and how to care for the baby.”
Half of the babies born with Edward syndrome do not live past the first week of life. 90% of the children who do survive the first week do not survive the first year. Some children have survived into their teenage years; however, they do so with serious medical and developmental problems.
You can find information on current clinical trials on www.clinicaltrials.gov. If you would like your child to be involved in clinical trials at the NIH Clinical Center, you may contact the NIH Patient Recruitment Office at 800/411-1222 or email firstname.lastname@example.org.
There are a number of support groups throughout the US for families with children who have Patau or Edward syndrome:
- Support Organization for Trisomy 18, 13 and Related Disorders (SOFT) – trisomy.org.
- Trisomy 18 Foundation – trisomy18.org.
- Hope for Trisomy 13 and 18 – hopefortrisomy13and18.org.
If you would like more information or resources in your area relating to Patau syndrome, Edward Syndrome, or any other developmental disability, please contact NARIC’s information specialists by calling 800/346-2742, via email, or by chat.